Circular No. 31/2024/TT-BTNMT on technical procedures for marine environment investigation, survey of coastal areas and islands

CIRCULAR

Technical regulations for marine hydrographic and environmental surveys in coastal areas and islands

marine, coastal environment, and islands

Pursuant to the Law on Marine Resources, Environment, and Islands dated June 25, 2015;

Pursuant to Decree No. 68/2022/NĐ-CP dated September 22, 2022 of the Government on the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

At the proposal of the Director of the Vietnam Marine and Island Administration;

The Minister of Natural Resources and Environment promulgates this Circular on technical regulations for marine hydrographic and environmental surveys in coastal areas and islands.

PART I

GENERAL PROVISIONS

Article 1. Scope of Regulation

This Circular stipulates the procedures, contents, and requirements for marine hydrographic and environmental surveys in coastal waters up to 20 meters deep in Vietnam's territorial waters for the following types of work:

1. Marine meteorological survey.

2. Marine hydrographic survey.

3. Marine environmental survey.

4. Seabed depth survey.

5. Marine ecological survey.

Article 2. Applicability

This Circular applies to agencies, organizations, and individuals conducting marine hydrographic and environmental surveys in coastal waters and islands of Vietnam.

Article 3. General Principles for Marine Hydrographic and Environmental Surveys in Coastal Waters and Islands

1. Compliance with the steps, procedures, standards, and specifications for each specific type of work when conducting surveys.

2. The quality of products from surveys must reflect the characteristics of natural conditions in the surveyed area.

3. During the implementation of surveys, compliance with laws on environmental protection, biodiversity, fisheries, cultural heritage, underwater and surface structures, and not hindering marine economic activities must be ensured.

4. Ensure strict adherence to labor safety regulations during marine surveys.

5. In case of unusual data during marine hydrographic and environmental surveys in coastal waters and islands, re-surveying and re-checking should be conducted, the cause identified, and reported to management authorities if necessary.

6. Organize inspection and acceptance of quantity and quality of products after completing the task.

Article 4. Explanation of Terms

1. Broad station refers to a station where observation is conducted once after the vessel stabilizes at a position, then moves to another station to examine spatial changes in marine resource and environmental factors.

2. Continuous station involves continuous observation over extended periods (hours, days) to examine temporal variations in marine resource and environmental factors and their interrelationships.

3. Observation layer refers to the vertical distance from the calm sea surface to the observation point.

Article 5. Survey Elements and Measurement Frequencies

Table 01. Survey Elements and Measurement Frequencies

Article 6. Main Monitoring, Measurement, and Analysis Equipment

Table 2. Main Monitoring, Measurement, and Analysis Equipment

Chapter II

TECHNICAL REGULATIONS FOR INVESTIGATION AND SURVEY WORK

Section 1

INVESTIGATION AND SURVEY OF MARINE METEOROLOGY

Article 7. Principles of Investigation and Survey

1. Ensure compliance with general principles for marine hydrographic investigation and survey, coastal and island environment investigation and survey as stipulated in Article 3 of this Circular.

2. Marine meteorological investigation and survey work must comply with the National Technical Regulations on Meteorological Observation, code QCVN 46:2022/BTNMT, issued by the Minister of Natural Resources and Environment under Decision No. 14/2022/TT-BTNMT dated October 27, 2022, and the user manuals for meteorological measuring instruments and equipment provided.

Article 8. Preparation work

1. Prepare equipment for meteorological measurement fully and check their operational status. Prepare backup equipment.

2. Check the validity period of calibration certificates according to current laws on measurement. In cases exceeding the prescribed period, recalibration of meteorological measuring equipment must be conducted.

3. Prepare materials for observation and calculation.

4. Prepare supplies and office materials for marine meteorological investigation and survey.

5. Fully prepare personal protective equipment.

Article 9. Investigation and Survey Work

1. General Requirements

a) The observation position and installation location of instruments must be at an open place, the highest point on the ship, unaffected by surrounding obstructions;

b) The off-going watch must check and record the handover logbook with the previous watch's duties;

c) The shift handover process must be completed fifteen minutes before the full hour;

d) For wide-range stations: When the ship arrives at the survey point, it must stop completely and stabilize before conducting measurements according to Table 01;

đ) For continuous stations: When the ship arrives at the survey point and proceeds to anchor firmly, then conduct measurements according to Table 01;

e) Collect and clean up machinery, equipment, and supplies when the survey trip concludes.

2. Measuring Air Temperature and Humidity

a) Before the measurement time, take the humidity measuring tool to the measurement location. In winter, take the tool out 15 minutes prior, in summer, take it out 10 minutes prior;

b) Four minutes before observation, moisten the fine cloth wrapped around the mercury bulb of the wet thermometer (right side) and wind up the clockwork fan;

c) Immediately after moistening and winding up, hang the humidity measuring tool on the external support arm of the ship facing the wind;

d) After three minutes of operation, read the dry thermometer (left side) and wet thermometer (right side) values sequentially. Record the decimal part first (tenth degree) and then the whole number, and enter the results into the marine meteorological observation form;

đ) Clean up, wipe, and store the humidity measuring tools after completing the measurement.

3. Measuring Atmospheric Pressure

a) Place the atmospheric pressure measuring device on a stand approximately 1.4 meters high inside the ship's cabin or in a location not affected by heat from engine rooms, kitchens, or stoves;

b) Do not change the position or move the atmospheric pressure measuring device;

c) During measurement, open the protective case of the atmospheric pressure measuring device and read the temperature value;

d) Lightly tap the finger or use a pencil to gently knock on the glass surface of the atmospheric pressure measuring device and read the atmospheric pressure value;

đ) Enter the result into the marine meteorological observation form;

e) Close the protective case of the atmospheric pressure measuring device after completing the measurement.

4. Measuring Wind

a) At the measurement time, take the anemometer, stopwatch, and compass to the measurement location;

b) Raise the anemometer to the roof of the cabin, choose an open spot, determine the height of the anemometer above sea level, read and record the initial readings of the instrument;

c) Hold the anemometer in the right hand, lift it above head level so that the axis of the instrument is vertical, the face towards the observer. Hold the stopwatch in the left hand. Simultaneously start the stopwatch, release the brake on the anemometer to allow the needle to move. Maintain this position for 100 seconds and at the last second, pull down the brake to stop the needle. If the wind is very weak, extend the measurement time to 200 seconds or more;

d) Read and record the second reading on the marine meteorological observation form;

đ) Determine the wind direction using the compass;

e) Collect, clean, and store the compass, stopwatch, and anemometer after completing the measurement.

5. Observing Clouds

a) The observer estimates (assesses) the total cloud cover (tenths of the sky) using the naked eye, regardless of the type or nature of the clouds;

b) The observer estimates (assesses) the cloud cover below the sky using the naked eye, including vertically developed clouds;

c) Identify the type and form of clouds in the sky based on the World Meteorological Organization (WMO) standard cloud atlas images or cloud classification tables;

d) Determine the base height of low and middle clouds not exceeding 2,500 meters;

đ) Enter the results into the marine meteorological observation form.

6. Observing Visibility

a) The targets for determining visibility must be clearly visible from the observer's position under an angle not greater than 5 - 6º from the horizon;

b) Determine visibility according to the visibility classification table;

c) Determine visibility in both directions: seaward and landward. Enter the results into the marine meteorological observation form.

7. Observing Weather Phenomena

a) Observe hydrometeorological phenomena: Rain, drizzle, hail, fog, and other phenomena;

b) Observe lithometeorological phenomena: Dry haze, smoke, and other phenomena;

c) Observe electrometeorological phenomena: Thunderstorms, lightning, and other phenomena;

đ) Enter the results into the marine meteorological observation form.

Article 10. Processing Data and Reporting Results

1. Calibrate temperature and humidity measurement results according to the calibration certificate of the machine, use the humidity table to calculate relative humidity, absolute humidity, saturation difference, dew point.

2. Calibrate air pressure measurement results: calibrate the scale, calibrate the temperature, and perform additional calibration. Convert atmospheric pressure to sea level.

3. Calibrate wind measurement results: based on the calibration certificate of the wind measuring machine, convert the number of revolutions to wind speed.

4. Calculate the characteristics of each meteorological factor.

5. Determine trends and changes in meteorological factors over space and time.

6. Summarize and report the results.

Article 11. Inspection and Acceptance

1. Inspect the volume of work performed, assess and evaluate the quality of the results achieved from the survey and investigation trip.

2. Evaluate the collected data set and compare it with the general laws of weather patterns in the research area and their impact on other factors.

3. Organize reports on results, summarize, and draw lessons for subsequent survey trips.

Article 12. Submitted Products

1. Compile the results of surveys and investigations of marine meteorological factors.

2. Report on the summary, evaluation, and preliminary comments on the results obtained during the marine meteorological survey trip.

3. Recommend and propose regarding the work of marine meteorological surveys in the next phase, identify points that need to be surveyed and measurement frequency to meet the requirements of the task.

Section 2

SURVEY AND INVESTIGATION OF COASTAL AND MARINE ENVIRONMENT

Article 13. Principles of Survey and Investigation

1. Ensure compliance with general principles for survey and investigation work of coastal and marine environment, coastal environment, and islands as stipulated in Article 3 of this Circular.

2. Marine environment survey and investigation work must comply with the National Technical Regulation on Marine Environment Monitoring QCVN 69:2021/BTNMT issued by Decision No. 08/2021/TT-BTNMT dated June 30, 2021 of the Minister of Natural Resources and Environment and related guidance documents for using marine environment monitoring equipment.

Article 14. Preparation Work

1. Check the validity period of the calibration and verification certificates for equipment requiring calibration and verification. In cases where the validity period has expired, calibration and verification must be conducted before proceeding with measurements.

2. Install software controlling the operation of flow, wave, and water level measuring devices on computers.

3. Check the connection capability and data transmission between flow, wave, and water level measuring devices and computers.

4. Prepare and check the operational status of marine environment measuring devices.

5. Prepare backup equipment.

6. Prepare documents serving the survey and investigation.

7. Prepare materials and office supplies for marine environment survey and investigation.

8. Fully prepare labor protection tools.

Article 15. Survey and Investigation Work

1. General Requirements

a) The observation positions must be representative of the surveyed marine area, unaffected by terrain and surrounding obstacles such as near islands, river mouths, and offshore structures affecting currents and waves;

b) The off-going watch must check and record the handover logbook with the previous watch's duties;

c) The shift handover process must be completed fifteen minutes before the full hour;

d) For wide-area stations: When the vessel arrives at the survey point, the vessel must stop completely and stabilize before conducting measurements of the elements according to Table 01;

đ) For continuous stations: When the vessel arrives at the survey point, the independent buoy station system will be deployed (according to Diagram 01 for single-element measuring machines or Diagram 02 for multi-element integrated machines). Afterward, anchor the vessel to stabilize at a distance of 3 to 5 times the deployment depth from the machine. Conduct surveys of the elements according to Table 01;

e) Conduct depth measurements at all types of survey stations;

g) Deploy the independent buoy station system so that the machine is balanced at the seabed to ensure the quality of the collected data;

h) Retrieve the machines, clean the machines, equipment, and materials when the survey trip concludes;

2. Wave observation by eye

a) Determine the wave direction using a compass;

b) Estimate the wave height visually;

c) Continuously observe the wave height for 5 minutes;

d) Record all observed wave heights within 5 minutes on scratch paper, then cross out all except the five highest waves and record them in the marine environment observation chart;

đ) Cross out under the highest wave and find the corresponding wave category;

3. Measure current directly with a current meter

a) Check and calibrate the time information;

b) Adjust the LCD display contrast;

c) Perform zero-point correction for the current and depth sensors;

d) Use a nylon rope to suspend a weight (10 kg), do not use chain;

đ) Lower the current meter to the predetermined measurement layer at a rate of 0.5 m/s. At each measurement layer, measure for 2 minutes and record the direction and speed of the current in the current observation logbook. Save the direction and speed of the current in the meter's memory;

e) Retrieve the meter, wash the meter and ropes, clean the display part when the measurement is complete. Store the current meter in protective containers;

4. Measure current with a self-recording current meter

a) Install batteries for the current meter, connect the current meter to the computer;

b) Set measurement parameters and memory format;

c) Apply a thin layer of silicone to all waterproof seals on the current meter, install the cover, tighten all screws;

d) Accurately calculate the length of the rope for lowering the meter suitable for the depth of the survey station, place the current meter at the required measurement layer. Install the marker buoy, signal buoy, flashing light, tension buoy, and weight on the rope in a U-shape;

đ) Lower the current meter, ensuring the rope suspending the meter is straight, with a maximum tilt angle of the rope ≤ 10º;

e) Arrange personnel to continuously monitor the self-recording current meter until the measurement is completed;

g) Retrieve the self-recording flow meter at the end of measurement. Rinse the machine with clean freshwater, dry it. Export data from the meter's software to a computer file for storage. Remove the power battery, rinse the cable, buoy, light, and other tools clean. Store the flow meter in a protective box.

5. Measure waves using a self-recording wave meter.

a) Install the power battery for the wave meter, connect the wave meter to the computer;

b) Set measurement parameters and memory format;

c) Apply a thin layer of silicone to all water seals on the wave meter, install the waterproof plug;

d) Install the wave meter protective frame. Accurately calculate the length of the meter cable suitable for the depth of the survey station. Attach the marker buoy, signal buoy, flashing light, tension buoy, and weight to the cable in a U-shape;

đ) Arrange personnel to continuously monitor the wave meter until the end of measurement;

e) Retrieve the wave meter at the end of measurement. Rinse the machine with clean freshwater, dry it. Export data from the meter's software to a computer file for storage. Remove the power battery, rinse the cable, light, buoy, and other tools clean. Store the wave meter in a protective box.

6. Measure water level using a self-recording water level meter.

a) Install the power battery for the water level meter, connect the water level meter to the computer;

b) Set measurement parameters and memory format;

c) Apply a thin layer of silicone to all water seals on the water level meter;

d) Install the water level meter protective frame. Accurately calculate the length of the meter cable suitable for the depth of the survey station. Attach the marker buoy, signal buoy, flashing light, tension buoy, and weight to the cable in a U-shape;

đ) Turn on the water level meter, release the water level meter;

e) Arrange personnel to continuously monitor the water level meter until the end of measurement;

g) Retrieve the water level meter at the end of measurement. Rinse the machine with clean freshwater, dry it. Export data from the meter's software to a computer file for storage. Remove the power battery, rinse the cable, light, buoy, and other tools clean. Store the water level meter in a protective box.

7. Diagram of meter deployment at independent buoy station

Figure 01. Diagram of positions of flow and water level measuring devices at independent buoy station

 

Figure 02. Diagram of positions of wave, flow, and water level measuring equipment at independent buoy station

Article 16. Data processing and reporting results

1. Use specialized software to process wave data, extract data into a file according to the software format, and convert to Excel file format.

2. Use specialized software to process flow data, extract data into a file according to the software format, and convert to Excel file format.

3. Use specialized software to process water level data, extract data into a file according to the software format, and convert to Excel file format.

4. Adjust flow data, create frequency tables, calculate harmonic constants, draw flow hydrographs, and other flow characteristics.

5. Adjust wave data, determine wave direction, period, height characteristics, and predominant direction.

6. Adjust water level measurement data, draw water level fluctuation curves, determine maximum, minimum, and average characteristics.

7. Summarize and report results.

Article 17. Inspection and Acceptance

1. Inspect the volume of work performed, assess and evaluate the quality of the results achieved from the survey.

2. Evaluate the set of collected data, determine the characteristics and patterns of marine environmental factors in the study sea area and their impact on other factors.

3. Organize reports on results, summarize, and draw lessons for subsequent survey trips.

Article 18. Submitted Products

1. A set of data results from investigating and surveying marine environmental factors.

2. A summary report evaluating and providing preliminary comments on the results obtained during the marine environmental survey.

3. Recommendations and proposals for marine environmental investigation and survey work in the next phase, identifying points to be surveyed and measurement frequency to meet the requirements of the task.

Section 3

MARINE ENVIRONMENTAL INVESTIGATION AND SURVEY

Article 19. Principles of Investigation and Survey

1. Ensure compliance with general principles for marine hydrographic investigation and survey, coastal and island environment investigation and survey as stipulated in Article 3 of this Circular.

2. Marine environmental investigation and survey work must comply with the provisions stipulated in: TCVN 6663-1:2011 (ISO 5667-9:2015) on water quality - sampling - Part 9: Guidance on sampling seawater and TCVN 6663-3:2016 (TCVN 8880:2011) on water quality - sampling - Part 3: Guidance on sample preservation and treatment; Circular No. 01/2023/TT-BTNMT dated March 13, 2023 issued by the Minister of Natural Resources and Environment regarding National Technical Regulation QCVN 10:2023/BTNMT on seawater quality; Circular No. 20/2017/TT-BTNMT dated August 8, 2017 issued by the Minister of Natural Resources and Environment on economic and technical norms for environmental monitoring activities; Circular No. 10/2021/TT-BTNMT dated June 30, 2021 issued by the Minister of Natural Resources and Environment on technical guidelines for environmental monitoring and management of monitoring information and data.

3. Marine sediment environmental investigation and survey work must comply with the provisions stipulated in: TCVN 6663-3:2008 (ISO 5667-3:2003) - Water Quality - Sampling. Part 13: Guidance on sampling mud water, wastewater sludge and related sludge; TCVN 6663-15:2004 (ISO 5667-15:1999) - Water Quality - Sampling. Guidance on sample preservation and treatment of sludge and sediment.

Article 20. Preparation Work

1. Prepare and check the operational status of sampling and measuring equipment for marine environment. Maintenance before and after each investigation and survey period.

2. Check the validity period of calibration certificates for equipment that requires calibration. In cases where the validity period has expired, calibration must be conducted prior to measurement.

3. Develop a construction design plan for the survey area, including: location of survey stations; types of marine environmental samples expected at one survey station; water quality parameters; foundational materials for the outline (natural and socio-economic characteristics, research history, geological features, sedimentation, previous studies on marine pollution areas...), research methods, workload, submitted products, and implementation organization.

4. Prepare documents, tables, investigation and measurement regulations.

5. Purchase and prepare tools, materials, chemicals, office supplies for investigating and surveying marine environmental factors, sample preservation: logbooks, pens, protective equipment, chemical preservatives.

6. Install equipment and tools for marine environmental investigation and survey.

7. Charge batteries for machines and measuring devices, check battery voltage.

8. Conduct trial survey, measurement, monitoring, and sampling operations.

Article 21. Survey and investigation work

1. Measuring seawater transparency

a) Wait for the ship to stabilize after anchoring, measure transparency on the side of the ship with shade. Avoid areas near the ship's wastewater discharge and areas with oil slicks on the water surface;

b) Slowly lower the transparency disk vertically until it touches the water surface, mark the position of point 0, continue lowering the disk until it can no longer be seen, lift and lower the disk several times at this depth;

c) Measure three times, take the average depth value, record the result on the measurement chart.

2. Measuring water quality parameters: DO, pH, salinity, temperature, and turbidity

a) Install batteries for the DO, pH, salinity, temperature, and turbidity measuring machines;

b) Calibrate the automatic pH sensor with pH4 standard solution;

c) Immerse the sensor into the water sample to be measured. Measure sea water temperature and DO first, then measure salinity and turbidity, and finally measure pH;

d) Record the results on the environmental survey and measurement form.

3. Collecting marine water environment samples

a) Wait for the ship to stabilize after anchoring, measure the depth at the survey positions, collect samples from the side of the ship facing the wind using a water sampling device (batomet), avoiding areas contaminated by ship wastewater;

b) The sampling device is attached to a weight to ensure that the sampling line does not skew;

c) Lower the water sampling device to the required sampling layer;

d) Collect samples to measure temperature, salinity, DO, pH, and turbidity at the surface, middle, and bottom layers;

đ) Collect samples for analyzing nutrients NH₄⁺, PO₄^3- at the surface, middle, and bottom layers;

e) Collect heavy metal samples (Cu, Pb, Cd, Fe, Mn, Zn, As, Hg, Total Cr, Cr⁶⁺) at the surface, middle, and bottom layers;

g) Collect mineral oil samples at the surface layer. The required water sample volume is 2 liters;

h) Fluoride (F-), Cyanide (CN-), Total Phenol, Total Coliform, Total Petroleum Hydrocarbons (TPH), Total DDT, Total Suspended Solids (TSS), Anionic Surface Active Agents.

4. Collecting marine sediment environment samples

a) The sediment composition of the environmental sample must have a high fine particle content (mud, mud-sand, sand-mud...);

b) When the ship arrives at the survey point, wait for the ship to stabilize after anchoring, measure the depth, then proceed to release the shovel. The cable must be released in a direction relatively perpendicular to the sea surface;

- When the shovel reaches the bottom (the cable slackens), pull up slowly without tangling the cable, ensuring the amount of sample collected (approximately 0.3-0.5 kg/sample);

- Once enough samples are collected, move the ship to the next survey location and clean the equipment to prepare for the next station;

5. Collecting surrounding air environment samples

a) Ensure that the air collection location is not locally polluted by ship activities (the highest point of the ship, not obstructed);

b) Determine wind direction and speed. Observe and preliminarily assess weather conditions;

c) Choose a location and securely install the equipment in an appropriate position;

d) Pump the prepared absorbent solution and hold the sample into the corresponding tubes and attach them to the air sampling location. Adjust the time-setting device for the equipment. Check the Rotameter, adjust the flow rate to the appropriate value, and start the generator;

đ) At the end of the sampling process, transfer the samples to the analysis and storage unit;

e) In cases of sampling during the journey, record the starting and ending coordinates and the beginning and ending times of the sampling process;

g) Parameters such as CO, SO₂), nitrite (NO₂, total suspended particulate matter (TSP) may be measured directly using equipment. Technical requirements shall be applied according to the technical procedures specified in Appendix 2.1. Method for monitoring ambient air (Table 6. Sampling and on-site measurement methods for ambient air), Circular No. 10/2021/TT-BTNMT dated June 30, 2021 issued by the Minister of Natural Resources and Environment regarding Technical Regulations for Environmental Monitoring and Management of Monitoring Information and Data;

h) The sampling time for total suspended particulate matter (TSP) is 24 hours, for SO₂ is 1.5 hours, for NO₂ is 1 hour, for O₃ is 1 hour, and for CO is 20 minutes.

6. Sample preservation

a) Marine water sample preservation work

The sample storage containers and preservation methods shall be carried out in accordance with TCVN 6663-3:2016 ISO 5667-3:2012 Water Quality - Sampling. Part 3: Preservation and Handling of Water Samples.

b) Marine sediment environment sample preservation work

Follow the provisions set forth in TCVN 6663-15:2004 Water Quality - Sampling. Part 15. Guidance on Preservation and Handling of Sediment and Sludge Samples.

c) Air environment sample preservation

Preserve SO₂), nitrite (NO_x, O₃, and CO samples in refrigerated cabinets. Preserve glass fiber filter paper for TSP dust samples in plastic bags in a dry environment.

7. Sample analysis

a) On-site rapid measurement work

The method of measuring marine water samples at the site for water quality parameters shall comply with the provisions of Section 3. Determination Methods of National Technical Regulation on Marine Water Quality QCVN 10:2023/BTNMT promulgated by Circular No. 01/2023/TT-BTNMT dated March 13, 2023 issued by the Minister of Natural Resources and Environment on National Technical Regulations on Ambient Environmental Quality and Appendix 2.4. Marine Water Quality Monitoring Methods accompanying Circular No. 10/2021/TT-BTNMT dated June 30, 2021 issued by the Minister of Natural Resources and Environment on Technical Regulations for Environmental Monitoring and Management of Monitoring Information and Data.

b) Marine water sample analysis work

The method of determining marine water quality parameters shall comply with the provisions of Section 3. Determination Methods of National Technical Regulation on Marine Water Quality QCVN 10:2023/BTNMT promulgated by Circular No. 01/2023/TT-BTNMT dated March 13, 2023 issued by the Minister of Natural Resources and Environment on National Technical Regulations on Ambient Environmental Quality.

Accept analytical methods guided in other national and international standards with equivalent or higher accuracy than the referenced standards.

c) Marine sediment environment sample analysis work

The method for analyzing and determining marine sediment environmental parameters is carried out in accordance with the National Technical Regulation on Sediment Quality QCVN 43:2017/BTNMT issued together with Circular No. 78/2017/TT-BTNMT dated December 29, 2017 of the Minister of Natural Resources and Environment on issuing national technical regulations on the environment.

Accept analytical methods guided in other national and international standards with equivalent or higher accuracy than the referenced standards.

d) Air quality analysis work

The method for analyzing and determining ambient air environmental parameters is implemented according to Article 2.1 of Circular No. 10/2021/TT-BTNMT dated June 30, 2021 of the Minister of Natural Resources and Environment on Technical Regulations for Environmental Monitoring and Management of Monitoring Information and Data (Appendix 2.1. Ambient Air Monitoring Methods (Table 7. Laboratory Analysis Methods)).

Article 22. Processing Data and Reporting Results

1. Processing data after surveying

a) Completing logbooks and sample registers; checking samples, preserving samples;

b) The results after processing are stored in comprehensive measurement charts, on CDs or in computer files;

c) Considering stations to be surveyed in the next round, drawing lessons from implementation;

d) Establishing actual documentation maps of the survey must include content showing types of samples taken at survey stations, preliminary assessment of field measurement results;

đ) Preparing a survey result report containing content reflecting the volume completed, assessing advantages and difficulties, reasons for increases or decreases in volume, a preliminary assessment of the characteristics of the surveyed water area through field measurements, factors affecting seawater quality;

e) Selecting samples, preparing sample analysis forms, and sending samples for analysis.

2. Processing data, establishing maps, and reporting

a) Receiving and evaluating the quality of marine water sample analysis results;

b) Processing data: dividing sample sets for calculation, based on the number of samples and the content of the report, statistical processing may use different software but must include basic statistics (minimum value, maximum value, average value, values exceeding permissible standards), establishing parameter tables, correlation matrix tables, trend graphs of concentration changes;

c) Plotting sea water temperature, salinity, and other factor variations;

d) Interpreting data: interpretation must be based on actual documentation results, analysis results, verification, and related technical standards, regulations;

đ) Preparing a report that must include the following main contents: Factors affecting seawater and marine sediment environments, geochemical characteristics of seawater and marine sediment environments, distribution characteristics of elements in seawater and marine sediments, comparison with environmental standards and regulations to identify polluted areas and pollution risks, causes, and pollution reduction measures;

e) Establishing current status maps (diagrams) of the marine environment (water and sediment): Showing the positions and depths of survey stations, geochemical environment according to analysis results, distribution of abnormal environmental quality parameters, pollution and pollution risks, factors affecting the marine environment.

Article 23. Inspection and Acceptance

1. Inspect the volume of work performed, assess and evaluate the quality of the results achieved from the survey.

2. Evaluation of the collected data set.

3. Organize reports on results, summarize, and draw lessons for subsequent survey trips.

Article 24. Submitted Products

1. Set of survey and investigation results data. Field diaries, samples, analysis results.

2. Summary report, evaluation and comments on preliminary results obtained during the survey and investigation trip regarding the marine environment.

3. Recommendations and proposals for marine environmental survey work in the next phase, identifying points to be surveyed and measurement frequency to meet the requirements of the task.

Section 4

DEEP SEABED SURVEY AND INVESTIGATION

Article 25. Principles of Survey and Investigation

1. Ensure compliance with general principles for marine hydrographic investigation and survey, coastal and island environment investigation and survey as stipulated in Article 3 of this Circular.

2. The factors measured and the frequency of measurements for seabed depth survey work shall be carried out in accordance with Article 5 of this Circular.

3. All measurement and positioning activities shall be conducted on the VN-2000 coordinate system. Conversion of WGS-84 coordinates obtained from the GPS system shall be performed using parameters as prescribed by laws governing the use of conversion parameters between the international WGS-84 coordinate system and the national VN-2000 coordinate system.

4. Depth measuring equipment must be calibrated accurately according to the draft of the echo sounder head, corrected for scale errors and sound speed. Corrections must be made for wave influences such as pitching, rolling, and heaving.

5. Survey line depth, positioning, and navigation software must be modern, capable of collecting and integrating data from positioning, depth measuring, wave influence measuring, navigation devices, determining the coordinates of points, sending signals and data to peripheral devices. All data from all sources must be stored in a database created by the software for post-processing tasks.

6. Products used for processing data from different survey tasks on board, preparing topographic reports.

7. Mathematical basis and accuracy for survey line and station drawings must comply with current regulations applicable to each scale of topographic maps corresponding to specialized survey maps.

Article 26. Preparation and Installation Work

1. Receive and inspect the operational status of machinery and equipment for the system installed on the survey vessel.

- DGPS positioning machine;

- Digital compass;

- Wave influence correction machine;

- Computer with depth survey software installed, printer;

- Backup equipment for the aforementioned machines.

2. Prepare backup machines and equipment.

3. Receive and inspect the operational status of measurement equipment used for testing.

4. Configure software parameters.

a) Declare the coordinate system as VN-2000, declare the transformation parameters from WGS-84 to VN-2000.

b) Declare the communication ports of the devices with the computer, check the connection and data transmission between the devices and the computer.

c) Declare the survey lines and targets for ship navigation.

- Survey lines within the scope of ship and boat surveys are designed parallel to the slope of the terrain;

- Around islands and along the coast, specific survey lines do not need to be designed. When measuring, the ship or boat will run close to the shore at a safe distance;

- Check survey lines are designed to intersect deep survey lines at angles from 60º to 90º, with the total length of check lines not less than 10% of the total length of deep survey lines;

- Sampling and observation station placement points are designed as circles with radii equal to the allowable tolerance of sampling and station placement positions. Each point is linked to a target in the navigation and positioning software.

5. Installation, Testing, Calibration of the System

a) The measurement and positioning system used for shallow water survey vessels includes interconnected equipment as shown in Diagram 03.

Diagram 03. Measurement and Positioning System Diagram

b) Equipment must be securely installed in appropriate locations on the survey vessel following the instructions for each type of equipment;

c) The antenna of the positioning machine must be placed in an unobstructed location, avoiding electromagnetic interference and multi-path effects;

d) The gyro compass must be securely installed on a flat surface so that its direction accurately indicates the true heading of the vessel. For satellite compasses, both antennas must be installed like the positioning machine's antenna and on the same horizontal plane;

đ) The sensors of the wave correction machine must be placed near the center of gravity of the vessel, installed correctly and ensuring a horizontal plane for the machine to minimize installation-induced system errors;

e) The transducer of the depth measuring machine must be securely installed at the best position to avoid acoustic interference on the survey vessel;

g) After installing the entire system on the survey vessel, measurements must be taken to determine the following factors:

- Offsets of equipment on the survey vessel, the center of gravity of the vessel, points indicating the size, shape, and orientation of the vessel; antenna mounting points, compass antenna (satellite compass), sensor installation points for the wave correction machine, transducer installation points for the depth measuring machine, sample collection and observation device release points, draft marks;

Diagram 04. Example of measuring offsets of equipment on the vessel

- Establish a table showing changes in vessel draft according to speed and changes in load;

- Pitch and roll angle of the sensor plane of the wave correction machine relative to the vessel's longitudinal axis;

- Pitch and roll angle of the plane where the acoustic transmitter/receiver (transducer) of the depth measuring machine is mounted relative to the vessel's longitudinal axis;

- Installation-induced directional offset of the compass, transducer, and wave sensor relative to the vessel's longitudinal axis;

- Positions of the equipment must be represented in a spatial coordinate system with the origin at the vessel's center of gravity, the Y-axis aligned with the bow direction, and the X-axis perpendicular to the Y-axis pointing to the right. Measurement errors of off-center points from this origin must not exceed ± 1 cm. Measurement errors of angles of installed equipment must not exceed ± 1 degree.

6. Testing and Calibrating the System

Surveying and positioning equipment shall be tested in accordance with Circular No. 27/2011/TT-BTNMT dated July 20, 2011, issued by the Minister of Natural Resources and Environment, concerning testing and calibration of certain surveying equipment for marine maps.

Article 27. Survey and Exploration Work

1. Positioning for Survey Work

a) When guiding the vessel to the target location for deploying observation stations or sampling devices, the deployment point on the vessel must be selected as the corresponding device release point. This point must align with the designed target;

b) Once the device release position falls within the tolerance circle, the vessel must be stabilized within the circle to release the device;

c) Upon reaching the sampling position, this position must be marked again. The recorded data includes: the coordinate position of the device release point, depth of the survey area, time of marking. Device depth is recorded according to the information from the person releasing it;

d) Throughout the voyage conducting environmental and hydrographic surveys, positioning data must be recorded at intervals of every five seconds;

2. Tide Observation

Survey work must include tide observation. In cases where the survey area lies outside regions where tide data can be obtained from fixed hydrographic stations, tide water level data must be connected to the national height system;

3. Seabed Depth Measurement

a) The survey vessel must follow the position of the echo sounder head, during measurement, deviation from the course must not exceed 1 mm on the map scale, maximum speed of the vessel is 8 km/h;

b) When turning the vessel to enter the next course, speed must be reduced to ensure sufficient time for the wave correction system to eliminate lateral acceleration effects;

c) Positioning data, depth, compass, wave influence are continuously recorded by software throughout the measurement and verification routes;

d) Marking measurement points starts from the beginning of the route, the distance between two consecutive points must comply with current regulations for each specialized map scale, such as seabed topographic map creation;

đ) All events during depth measurement, route name, start and end times, direction of travel, data files must be meticulously recorded in the depth measurement logbook;

e) If any measuring device malfunctions causing loss of data over two consecutive marking points, that section must be remeasured;

g) Echo sounder head immersion depth is measured at the start and end of each shift. Note the measurement time to correct the echo sounder head immersion depth in data processing;

Article 28. Data Processing and Reporting Results

1. Editing tidal data, adjusting recording times if there is a time difference between the tide station and the vessel's surveying system, creating data files compatible with the data processing software requirements;

2. Creating separate data processing projects for each survey, loading survey data and tidal data into the software;

3. Data processing and editing are carried out for each survey route;

4. Adjusting measurement data based on acoustic velocity and echo sounder head immersion depth data;

5. Using cross-section data to eliminate erroneous depth and wave measurement points. Calibrating the delay between depth and wave measurements. Interpolating missing data without supplementary measurement;

6. Evaluating measurement accuracy based on current regulations using depth and verification measurement data;

7. Exporting X, Y, H coordinates of marked points into formats suitable for map editing and database software;

8. Preparing survey report drawings including survey routes, depth measurement points, station placement points, and hydrographic and environmental sample collection points;

9. Types of products:

- Processed coordinate and seabed depth data along survey routes and measurement points;

- Coordinate and elevation data of survey stations;

- Survey route and station drawings displayed on corresponding maps;

- Preliminary reports, evaluations, and observations of measurement results.

Article 29. Inspection and Acceptance

1. Inspect the volume of work performed, appraise and evaluate the quality of the results achieved from the survey trip.

2. Evaluate the set of collected data; compare and contrast preliminary results with other comprehensive results, the impacts and influences of the measurement outcomes on other environmental factors.

3. Organize reports on results, summarize, and draw lessons for subsequent survey trips.

Article 30. Submitted Products

1. A collection of survey results data. Drawings of lines, deep points, station placement points, sample survey oceanographic and environmental conditions displayed at corresponding scales.

2. Summary report, evaluation and initial comments on the results obtained during the survey for seabed depth measurements.

Section 5

MARINE ECOLOGICAL SURVEY AND INVESTIGATION

Article 31. Principles of Survey and Investigation

1. Ensure compliance with general principles for marine hydrographic investigation and survey, coastal and island environment investigation and survey as stipulated in Article 3 of this Circular.

2. Marine ecological surveys and investigations must comply with the Biodiversity Law 2008 and the Fisheries Law 2017.

3. To ensure quality safety objectives, the sample quantity for testing must be at least 20% for each sample, and the sample separation process must be carefully conducted. The analysis results meet requirements when 5 to 10% of the total number of samples sent for testing have matching analysis results between the first test and subsequent checks.

4. After the samples have been tested, they must be preserved long-term by soaking them in glass or plastic bottles containing 70% alcohol solution or other chemicals (depending on the sample fixation method).

Article 32. Preparation Work

1. Check the operational status of machines, equipment, tools, and perform regular maintenance before each survey round.

a) Survey vessels: Ships, speedboats, motorboats, cars, diving equipment;

b) Equipment and tools for collecting and preserving samples on-site;

c) Tools for investigating stock levels;

d) Sample preservation tools;

đ) Chemical tools for fixing fresh samples;

e) Field classification materials;

g) Cameras, video recorders, computers;

h) Logbooks according to general regulations for each group of organisms;

i) Medical supplies and equipment for on-site use in case of emergencies;

k) Clothing, shoes, boots, gloves (safety gear);

l) Sample labels, stickers, and other materials.

2. Calibrate, prepare machines, equipment, tools, materials, and chemicals.

3. Determine the coordinates of the station positions on the map.

4. Determine the locations and routes, stations for sampling that must meet the following criteria:

a) Representativeness;

b) Covering all habitats;

c) Covering the entire space;

d) Develop sampling and mapping diagrams with coordinates included.

5. Determine the sampling time: Representative of different seasons, ideally once every three months.

6. Identify the groups of organisms to be sampled.

Article 33. Survey and Investigation Work

1. Plankton Plants

a) Sampling work

- Surface layer sampling using funnel-shaped nets with mesh sizes of 20-25 micrometers, equipped with bottom suction tubes or other equivalent sampling devices. Nets should be vertically lifted from the seabed to the surface. If the angle exceeds 45º, the collected samples will only have qualitative value, not quantitative;

- Pull the net through the surface layer at a stable speed. For large nets (diameter over 45 cm), the pulling speed is 0.5 to 1 m/s; medium nets (diameter 25-45 cm) at 0.5 m/s; small nets (diameter under 25 cm) at 0.3 to 0.5 m/s. During net pulling, absolutely no stopping is allowed;

- After lifting the net out of the water, rinse the organisms into the suction tube with a water hose or bucket, then pour them into a bottle. Fix the samples with 5% formalin solution (or other chemicals) based on the volume of water in the bottle;

- Stratified sampling must be based on the stratification of hydrological layers: 0 to 10 meters, 10 to 20 meters. If the cable angle exceeds 30º, stratified sampling cannot be conducted;

- Stratified sampling using water sampling equipment: At least 1 liter of water must be collected. If the sample contains debris, oil slicks, or large aquatic animals with many tentacles, resample. When fixing the sample, add sufficient chemicals corresponding to the volume of water in the bottle. In cases where the net has a light bottom tube, the end of the net frame connected to the weight should weigh approximately 0.5 kg.

b) Sample Processing

- Pour the samples into appropriately sized small bottles;

- All sample bottles must have external and internal labels, which should be written with waterproof ink on acetate paper or similar material. Labels should include the marine area code, net type, collection time, and sample serial number for each survey round;

- Water samples collected using water sampling equipment must be centrifuged to reduce the water volume to about 5 to 10 ml, then preserved in small bottles with appropriate chemicals. These bottles must also be labeled;

- Samples from each water layer at each station should be placed in a larger bottle with labels indicating the station number.

c) Preservation and Transportation

- Preserving chemicals: Formaldehyde solution, Lugol's solution, or similar chemicals;

- Sample bottles with complete labels, pencils, waterproof pens, and survey logs. Regularly used sample bottles are typically made of thick plastic or glass for easy transportation during surveys; for quantitative samples, the bottle size varies depending on the research area, usually ranging from 0.1 to 1 liter;

- After collecting samples, the bottles should be packed in foam boxes, large PP plastic containers with lids, or similar materials for transport back to the laboratory for analysis.

d) Registering Samples

- All collected samples must be registered in the sample logbook;

- After registration, verification by another person is required.

đ) Analyzing Samples

- Qualitative sample analysis: Qualitative samples are brought back to the laboratory, allowed to settle, then a small amount of the sample solution is drawn up with a pipette onto a slide and observed under a microscope. Depending on the classification characteristics of each species, further steps such as sample cleaning, breaking down, separating, and staining cells for easier observation are carried out. While observing, take photos of representative samples for each species. Analysis is conducted using an Olympus microscope and a Leica fluorescent inverted microscope or equivalent equipment.

- Quantitative analysis: The quantitative sample is brought back to the laboratory and allowed to settle for at least 24 to 48 hours. A small siphon is used to gradually remove water from the sample bottles until sediment begins to appear. The sample is then transferred to a 100 ml cylindrical measuring tube and allowed to settle for at least one night. Water is removed using a siphon until sediment appears again, repeating this process until the volume of the sample in the measuring tube remains between 10 to 20 ml. The sample is then transferred to a small bottle with a volume of 10 to 20 ml for preservation. When analyzing, shake the sample bottle thoroughly, use a pipette to take 1 ml of the solution and place it in a Sedgewick-Rafter, Neubauer chamber, or equivalent material. Count the number of cells of each species under an inverted microscope such as a LEICA or equivalent.

- For species with high frequency of occurrence, a counting machine must be used. Count a portion, half, or the entire chamber depending on the cell density in the sample.

- After counting, the sample is returned to the preservation bottle. The counting chamber and pipette must be washed clean with distilled water before moving on to count another sample.

- The analysis results are updated in the counting table and the weight of phytoplankton cells is calculated.

2. Zooplankton

a) Sample collection

- Collect surface layer samples using nets: Various funnel-shaped nets with mesh sizes of 45 - 75 μm, equipped with bottom collection tubes or other equivalent sampling devices. Nets should be pulled vertically. If the angle exceeds 45º, the collected sample will only have qualitative value, not quantitative.

- Pull the net at a stable speed. For large nets (diameter over 45 cm), the pulling speed is from 0.5 to 1 m/s; medium nets (diameter from 25 to 45 cm) at 0.5 m/s; small nets (diameter under 25 cm) from 0.3 to 0.5 m/s. During net pulling, absolutely do not stop.

- After lifting the net out of the water, rinse the organisms into the collection tube with a water spray or pour from the outside, then transfer them to a bottle. Fix the sample with 5% formalin solution (or equivalent chemicals) based on the volume of water in the sample bottle.

- Stratified sampling must be conducted according to the stratification of the hydrological department: 0 to 10 meters, 10 to 20 meters. When the net reaches the upper limit of the water layer, stop and quickly release the stratification hammer to fold the net. If the cable angle exceeds 30º, do not collect stratified samples. Record the results of stratified sampling in the table.

- Quantitative samples are collected using a bathometer with a volume of 5 liters to 10 liters, pulling enough to filter 100 liters of water through the zooplankton sampling net, retaining no more than 200 ml of water with zooplankton. Then, the sample is preserved in a sample bottle (plastic, glass, or equivalent materials) and fixed with a 5% formalin solution (or equivalent chemicals).

b) Sample Processing

- Use a pipette with a fabric mesh cover to remove excess water from the sample bottle, transferring the sample to a smaller bottle suitable for the amount of sample.

- Each sample bottle must be labeled both externally and internally, with labels written in non-fading ink on carbon paper or equivalent materials. On the label, record the symbol of the investigation sea area, type of net, time of collection, and serial number of the sample in each survey round.

c) Preservation and Transportation

- Samples collected with nets are kept in a 5% formalin solution or equivalent chemicals.

- Samples collected with water extraction machines are kept in a 1% Lugol's solution or equivalent chemicals.

- In some cases, to prevent shell corrosion of zooplankton, the formalin solution must be buffered with sodium borate or sodium carbonate (Na₂CO₃) or equivalent chemicals.₂Add distilled water to make up to 1 liter of solution.₃- Sample containers are sample bottles (plastic, glass, or equivalent materials).

- After being properly preserved and labeled, zooplankton samples are placed in foam boxes, wooden boxes, or equivalent materials for transport back to the laboratory.

- Qualitative analysis: Determine the species composition using dissecting microscopes and compound microscopes.

d) Registering Samples

- All collected samples must be registered in the sample logbook;

- After registration, verification by another person is required.

đ) Analyzing Samples

- Identify up to the genus level using a dissecting microscope.

- Select fully developed individuals representing each group for dissection and identification of species using a compound microscope.

- Counting method: If the number of samples is small, count all of them. If the number of samples is too large, count all larger species. Record the counting results in the zooplankton individual counting table and the stratified sample counting results in the stratified net zooplankton individual counting table.

- Weighting method: Choose zooplankton species that serve as fish food for wet weight measurement. The scale must have a sensitivity of at least 0.01 mg. Remove debris and impurities before weighing the sample with an electronic balance accurate to 0.0001 g. Filter the sample through a sieve (mesh size 315 μm or equivalent). Dry the sample with filter paper to natural moisture content and then weigh the sample.

3. Benthos

- Collect samples using a sea scoop (volume from 0.15 m³ and contact area 0.1 m²) or similar tools: Observe and record the condition of the bottom sediment, thickness, and biological status. The mass of the bottom sediment must exceed half of the sea scoop or similar tool to meet requirements. The sampling area is 0.5 m² at each station. The depth of the sampling tool must reach a minimum of 4 - 5 cm for sandy bottoms with medium-sized shells, 6 - 7 cm for fine sand, and ≥ 10 cm for mud. If the sample does not meet any of these criteria, it must be re-collected. Rinse the sample through a sieve system (mesh size 0.5 - 5 mm). After rinsing, separate and sort each species or taxonomic group (individuals may be sorted by size) and place them in bottles for preservation.

a) Sampling work

- Collect samples using a large spade (with a volume of 0.15 m³ and a contact area of 0.1 m²)³and a contact surface area of 0.1 m²or similar tools: Observe and record the condition of the collected sediment samples, thickness, and current biological status. The weight of the sediment must be more than half of the large spade or similar tool to meet the requirements. The sampling area at each station is 0.5 m². The depth of the sampling tool must reach a minimum of 4-5 cm for a sandy bottom with medium-sized shell debris, 6-7 cm for fine sand, and ≥ 10 cm for mud. If any of the above criteria are not met when collecting samples, they must be re-collected. Rinse the samples through a sieve system (mesh size 0.5-5 mm). After rinsing, sort and separate each species or taxonomic group (individuals can be separated by size) and place them in preservative jars;²at each station. The depth of submergence of the sampling tool must be at least 4-5 cm for a sandy bottom with medium-sized biological shells, 6-7 cm for fine sand, and ≥ 10 cm for mud. If any of the above criteria are not met when taking samples, it is mandatory to retake the sample. Rinse the sample through a sieve system (sieve mesh size 0.5-5 mm). After rinsing, sort and separate each species or taxonomic group (individuals can be separated by size) and place them in preservative jars;

- Collecting samples using a bottom rake with a triangular frame (25 or 30 cm) or square frame (25 to 30 cm) attached with a mesh bag having a mesh size of 0.5 to 1 mm or equivalent tools: Lower the rake when the vessel is moving slowly at a stable direction. The length of the cable when pulling the net must depend on the speed of the vessel, depth, wind direction, and current flow. The speed of the vessel during pulling must be slow enough for the rake not to float. The time for pulling the bottom rake should be approximately from 5 to 10 minutes. A sample is considered to meet the requirements when the mesh bag contains one quarter of the bottom material (the length of the mesh bag should be more than 1.5 meters). Depending on the depth and speed of the current, different sizes and weights of bottom rakes should be used to prevent floating. Pour the sample from the mesh bag onto a sieve, rinse with water, and filter out non-sample materials through the sieve system before placing it in a sample bottle and fixing it in a 70 to 90 percent alcohol solution.

- Collecting samples in tidal zones: Collect samples in all three high tide, mid-tide, and low tide areas. Once the collection point is accurately determined, use a quantitative square frame of 0.25 m² (50 x 50 cm)² or 1 m

 (100 x 100 cm) placed on the tidal flat and then use a shovel or similar tool to dig down to 15 to 20 cm below the surface until no bottom animals are encountered;

- Collecting samples in seagrass beds: Depending on the area of the seagrass bed, determine the number of cross-sections needed, with a minimum of three cross-sections for each seagrass bed. On each cross-section, set up three sampling stations (two at the ends and one in the middle). At each station, collect four samples (three quantitative and one qualitative) using deep diving equipment such as Scuba or large ocean shovels (over 20 kg) or other tools. Pour the samples from the tools onto a sieve, rinse with water, and filter out non-sample materials through the sieve system before placing them in a sample bottle and fixing them in a 70 to 90 percent alcohol solution.²- Collecting samples on coral reefs: Use deep diving equipment such as Scuba or equivalent tools to collect bottom animal samples. Qualitative samples are collected along transects used for coral research. Along each transect, place about 3 to 5 survey stations. At each station, collect three square samples, each with an area of 1 m

b) Sample Processing

 (collecting all individuals present within the sampling square). Quantitative samples are collected at the same stations as the qualitative samples. At each station, collect three dead coral blocks weighing over 5 kg each. Use a hammer, knife, or chisel to extract all samples within the coral block, immerse them in a 70 to 90 percent alcohol solution, and label them properly.

- Separating samples: When transferring samples from the collection tools, remove objects that are not bottom animals. Among the bottom animals, separate those requiring anesthesia from those that do not. Further separate soft-bodied, easily damaged species and those with hard shells or spines.

- Culturing and Anesthetizing: To keep the sample specimens in their original living state after fixation, culturing and anesthetizing must be performed before immersing them in the preservation solution (allowing organisms to recover normally in seawater). Avoid mixing soft-bodied animals with predatory species, those with hard shells, or fast-swimming species (such as large crustaceans). Once the animals have recovered normally, gradually introduce anesthetics (alcohol, menthol, magnesium sulfate, etc.). During anesthesia, the anesthetic is administered in multiple doses, with the amount not being too large. Only after the bottom animals have completely lost sensation should they be immersed in a 70 to 90 percent alcohol solution for preservation.

- Qualitative Samples: For medium-sized bottom animals with hard outer shells (soft-bodied, crustaceans) or internal skeletons (sea cucumbers, sea anemones, echinoderms, etc.), use alcohol for preservation. For larger specimens with thick meat (Nudibranchia, squid, octopuses, or similar animals), directly inject alcohol into the body tissue using a syringe or fix the specimen with a 7 to 10 percent formaldehyde solution.

- Quantitative Samples: For quantitative specimens where accurate biomass calculation is required, use a 7 to 10 percent formaldehyde solution or a 70 to 90 percent alcohol solution to fix the entire living material in the organism's body. For species requiring microsurgical techniques during subsequent identification, after anesthesia, use a fixing solution (Bouin, neutral 10 percent formaldehyde, or equivalent chemicals).

c) Preservation and Transportation

- Preservative Chemicals: Alcohol, formaldehyde, Lugol's solution, or equivalent chemicals.

- Sample bottles with complete labels, pencils, waterproof ink pens, and field survey logs. For bottom animal sample bottles, typically plastic or thick glass bottles are used for easy transportation during surveys. For quantitative samples, the volume of the sample bottles usually ranges from 0.1 to 1 liter depending on the study area.

- After fixing the samples, the bottles are arranged in foam boxes, large plastic PP boxes with lids, or equivalent containers for transport back to the laboratory for analysis.

d) Registering and Recording Specimens

- After processing, specimens must be registered simultaneously in the field logbook and on the labels.

- Registration on the record sheet. The record sheet for qualitative sampling is used to register qualitative samples. The record sheet for quantitative sampling is used to register quantitative samples.

- Registration on labels and cards: Labels must be made of carbon paper or other materials that do not tear or smudge when soaked for a long time in alcohol, formaldehyde, or equivalent chemicals. Cards for registering samples must be made of plastic, aluminum, or other materials and must be engraved with numbers, have standardized dimensions, and have a hole drilled at one end for easy sorting, fixing, and storage.

đ) Analyzing Samples

- Comparing specimens, after comparison is completed, proceed to separate the samples for preparation for analysis. Qualitative and quantitative samples are separated. Separate different taxonomic groups such as sea cucumbers, sea anemones, ribbon worms, mollusks, crustaceans, sea urchins, or animals with distinct external appearances.

- Alcohol-soaked samples: Use an analytical balance with a sensitivity of 0.01 g to weigh. If the sample is also used for calculating dry weight, a consistent balance with a sensitivity of 0.01 mg must be used. Before weighing, the sample must be placed on absorbent paper to remove surface water. For living animals in tubes or nests that are too large, they must be removed; smaller ones may be kept intact to avoid damage. When weighing soft-bodied organisms, the shell does not need to be removed, but all water or alcohol inside the shell must be absorbed. For larger species with many individuals, the shell should be removed, but the live weight and shell weight must be weighed separately for reference.

- Weighing dry weight: After weighing the alcohol-soaked samples, each species or group of species at each station must be dried and then weighed. Large specimens must be dissected to remove internal debris. Species with calcium bones must be decalcified using diluted hydrochloric acid (0.1N HCl). Use an analytical balance with a sensitivity of 0.01 mg. Before weighing, the samples must be taken out of the drying cabinet and cooled in desiccators. Each sample must be weighed quickly.

4. Seaweed

a) Sampling work

- Community survey: Samples used for classification or museum storage must be collected from various locations, including floating, attached, and epiphytic species. The samples must be complete, with all organs present, bearing reproductive cells or sexual organs, and in mature or fully developed stages. At least five to ten samples of each species are required, and if a species is extremely rare, all encountered samples must be collected. For small seaweeds, rock-dwelling species, or those firmly attached, a knife or scraping tool should be used. Other types of seaweed can be collected by hand or with a rake.

- Surveying natural yield of economic seaweed: Determine the survey route. In coastal tidal areas, routes are set parallel to each other from high tide to low tide, up to where seaweed distribution ends. The process must ensure that there are at least three to five routes in a survey area. On each route, place three sampling stations (two at the ends and one in the middle). At each station, collect one quantitative sample (using a square frame of 50 x 50 cm, increasing the size of the frame in sparse areas) and collect all seaweed within the defined area vertically until none remain (collecting all parts of the seaweed such as roots, stems, leaves, flowers, fruits...). Fix the samples with 70-90% ethanol solution or other chemicals.

- In brackish or saltwater lagoons, the routes are arranged in a checkerboard pattern. The distance between routes depends on the lagoon's area and should not exceed 100 meters.

- Select sampling points: On each route, determine sampling points to calculate biomass. The distance between sampling points is based on the length of each route, with each route having five to ten sampling points (each point collects one sample).

- In areas with dense seaweed distribution and long sampling routes, the distance between sampling points should not exceed 50 meters.

- In areas with sparse seaweed distribution, the distance between sampling points should not exceed 30 meters. Collect samples within a defined area limited by square frames of 50 x 50 cm, increasing the size of the frame in sparse areas.

- In areas with dense or concentrated seaweed distribution, the sampling area only needs a square frame of 50 x 50 cm. In areas with sparse distribution, use larger frames.

- For some seaweed species with large quantities often washed ashore by waves (such asSargassum, Chnoosporaor similar conditions), it is necessary to calculate their biomass at shore points corresponding to the extended sampling lines reaching the main distribution area.

- When water depth exceeds the observation and sampling capability of the survey team, use deep diving equipment such as Scuba or equivalent tools to collect bottom animal samples.

- When collecting samples using the selected area frame, gather all seaweed individuals within the frame, including the root portion.

- After completing the sample collection, clean and separate each species, place each sample in breathable bags or materials, remove all adhering water, and weigh each species or variety.

- On the back of the survey chart, draw a diagram of the survey area, number the sampling lines and points. The sampling points must correspond to the numbers recorded in the survey chart for easy comparison during data processing.

b) Sample Processing

- Preparing dried seaweed samples: Choose representative seaweed samples with all organ parts (stem, tip, reproductive organs, or typical organs), wash them thoroughly with fresh water, and clean off any attached substances. Depending on the size of each seaweed sample, select appropriate paper sizes for pressing. Write basic information (collection location, time, sample number, gender of the sample, or notable characteristics) on the pressing paper with a pencil. Process and prepare the samples for museum storage.

- Preparing fresh seaweed samples: Freshly soaked seaweed samples are usually temporary and used for classification. Green algae (Chlorophyta) are soaked in a 7% formalin solution in seawater and a small amount of copper sulfate (CuSO4). Brown algae (Phaeophyta) are soaked in a 7% formalin solution in seawater. Red algae (Rhodophyta) are soaked in a solution of 68% seawater, 25% 90% alcohol, and 7% formalin, which may be stained with eosin before soaking. For soft, gelatinous red algae that easily disintegrate when soaked, add a small amount of glycerin or fix with other chemicals.

c) Preservation and Transportation

- Preservative Chemicals: Alcohol, formaldehyde, Lugol's solution, or equivalent chemicals.

- Sample containers with complete labels, pencils, waterproof pens, and field survey logs. For seaweed sample containers, thick plastic or glass boxes are typically used for easy transportation during surveys.

- After fixing the samples, pack them into foam boxes, large plastic PP boxes with lids, or equivalent containers for transport to the laboratory for analysis.

d) Registering and Recording Specimens

- After processing, specimens must be registered simultaneously in the field logbook and on the labels.

- Register on the sample log: The qualitative sample log is used to register qualitative samples. The quantitative sample log is used to register quantitative samples.

- Registration on labels and cards: The label must be made of carbon paper or other material that does not tear or smudge to ensure long-term preservation.

đ) Analyzing Samples

- Examine the internal structure of algae using various microscopes;

- For single-celled algae or filamentous algae, simply place them on a slide, cover with a coverslip, and observe under a microscope;

- For algae composed of multiple filaments aggregated (Calothrixor similar types of algae) or adhered together (Rivularia, Brachytrichaor similar types of algae after placing the sample on a slide, separate the sample with a fine needle, cover with a coverslip, and press firmly to separate the sample before observation;

- For algae with complex cellular structures, to observe the internal structures, it is necessary to cut them into thin slices either horizontally or vertically depending on the part to be observed;

- For algae treated with lime (some species in the family Corallinaceae or similar families), they should be decalcified prior to cutting by soaking the algae sample in acetic acid and nitric acid (for small algae, only acetic acid is needed) or other chemicals and then stained with chemical substances.

5. Seagrass

a) Sampling work

- Determine the area of the seagrass bed, select the position for cross-sections with sampling points (sampling points should represent the community of seagrass in the entire region and be easily accessible);

- Set up cross-sections: Typically, three cross-sections are set up at each site. The length of each cross-section depends on the area, usually ranging from 50 to 100 meters. Cross-sections are placed parallel to each other and parallel or perpendicular to the shore;

- Sampling begins from the 0-meter station of each cross-section, with subsequent stations spaced 10 meters apart. Continue this pattern until reaching the end of the cross-section;

- Identify seagrass species: Determine the seagrass species within the quantification frame;

- Determine coverage: Measure the percentage coverage of seagrass within the quantification frame (50 x 50 cm);

- Collect samples for biomass calculation: At each station spaced 10 meters apart along the cross-section, collect at least two to four quantification frames (20 x 20 cm, for larger seagrass) or two to four tubes (0.0035 m², for smaller seagrass) to calculate shoot density and seagrass mass;

- When water depth exceeds the observation and sampling capability of the research team, use deep diving equipment such as Scuba or equivalent devices to collect bottom-dwelling animal samples;

b) Sample Processing

- Collect dried pressed samples: Select representative seagrass samples with shoots, stems, roots, leaves intact, flowers, and fruits. Rinse thoroughly with fresh water, clean off any attached matter. Depending on the size of each seagrass sample, choose appropriate materials for pressing. Write basic information (collection location, time, sample number, gender of the sample or similar characteristics) on the pressing paper with a pencil. Arrange and prepare museum specimens;

- Prepare fresh submerged seagrass samples: Freshly submerged seagrass samples are used temporarily for classification. Seagrass species are immersed in a 5-7% formaldehyde solution or 70-90% alcohol or fixed with other chemicals;

c) Preservation and Transportation

- Preservative Chemicals: Alcohol, formaldehyde, Lugol's solution, or equivalent chemicals.

- Sample storage boxes with complete labels, pencils, waterproof ink pens, survey logs. For seagrass sample storage boxes, thick plastic or glass containers are typically used for easy transportation during surveys;

- After fixation, the boxes are packed into foam boxes or large PP plastic boxes with lids for transport back to the laboratory for analysis;

d) Registering and Recording Specimens

- After processing, specimens must be registered simultaneously in the field logbook and on the labels.

- Register on the sample log: The qualitative sample log is used to register qualitative samples. The quantitative sample log is used to register quantitative samples.

- Registration on labels and cards: The label must be made of carbon paper or other material that does not tear or smudge to ensure long-term preservation.

đ) Analyzing Samples

- Dry pressing samples: Collect all seagrass samples obtained from two to four quantification frames (quantification tubes) at each sampling station along the cross-section. Clean the leaves thoroughly, remove sediment and attached matter to avoid errors when weighing. Separate each seagrass species and carefully count each leaf and flower shoot;

- Measure biological parameters of seagrass: Use a ruler to measure the length of the leaf sheath, leaf length, and leaf width. To achieve accuracy, measure at least twenty leaf shoots;

- Separate seagrass parts: Above-ground parts (leaf shoots and flower shoots) and below-ground parts (stems and roots). Dry at 60°C for 24 hours, then weigh on an electronic scale with an accuracy of 0.01 mg;

6. Coral

a) Surveying fluctuations in coral species abundance

- Collect samples: Use diving equipment such as AquaLung, Scuba or equivalent tools to collect coral samples from reef areas from the coral zone to the reef base (depth of 30-40 meters). For massive coral species, use drilling materials to take samples. The collected samples are cleaned of flesh (soak in water for about 5-7 days, then rinse with high-pressure water to remove the flesh or use chemicals to clean);

- Film and photograph: Use video cameras and cameras to investigate the richness of coral species. All species encountered at the site are photographed closely enough to clearly identify taxonomic features;

- Analyze samples: Collected samples will be classified based on morphology and skeletal structure according to the classification system of Veron and Pichon (1976, 1978, 1980, 1982, 1986). For classification based on images, determine species composition based on color and morphology according to the living coral classification system of Veron 2000 or other classification systems;

b) Surveying fluctuations in coverage

- Rapid assessment method for coral reefs: The Manta tow method is used to quickly assess the status of a coral reef over a wide area including hard coral coverage, soft coral coverage, and large benthic invertebrate density. This method can only be performed in clear waters (minimum visibility of 6 meters, minimum depth of 3 meters). One person controls the boat and is responsible for the safety of the survey team. Another person observes and records underwater. A third person sits on the boat, sets positions, times, and oversees the technique to ensure it is carried out correctly while also being able to relieve the underwater observer if the survey covers a large area.

- Prior to initiating the manta tow, a person shall record weather parameters (rain/sun, wind, temperature), sea surface conditions, a preliminary description of the survey area, and the distance from the affected area (oil spill, toxic chemicals, or other impacts);

- When the underwater observer gives the start signal, the person controlling the vessel begins moving the boat. A person on board records the time and coordinates of the starting point. The speed of the boat is maintained at 3 - 5 km/h or equivalent;

- Two minutes after departure, the controller stops the boat for the underwater observer to record data (percentage cover of live coral, dead coral, and soft coral), which is then entered into a chart, while the person on board also records the coordinates of the stop point;

- The observer must pay additional attention to wave destruction, external impacts (urchins, oysters), and estimate the quantity during each tow;

- At a minimum, three parameters (hard coral, soft coral, and dead coral) must be recorded according to the agreed coverage scale or other index;

- Data analysis: After collecting all data in the field, the information will be entered into a computer in Excel format, and the data will be represented in graphs or maps;

Figure 05. Diagram of the Manta Tow Survey Method;

c) Reefcheck Method;

- Applicability: This method can be applied to all coral reefs that are 100 meters or longer in length with limited visibility where the Manta Tow method cannot be implemented;

- Selection of Survey Location: Choose locations near areas heavily impacted by incidents (oil spills, toxic chemicals, or other incidents), particularly avoiding reefs with steep cliffs and caves. Select reef sections at least 100 meters long with moderate slopes for cross-section placement. Describe the selected location and record necessary parameters such as latitude and longitude, distance from shore, distance from river mouth, and distance from the affected area (oil spill, toxic chemicals, etc.);

- Procedure: Lay out a 100-meter transect line parallel to the depth contour at depths of 2 - 6 meters and another line at depths of 6 - 12 meters. For narrow and shallow reefs, only one 100-meter transect line at depths of 2 - 6 meters is required. The 100-meter transect line is divided into four smaller segments, each 19.5 meters long (i.e., surveying segments from 0 - 19.5 meters, 25 - 44.5 meters, 50 - 69.5 meters, 75 - 94.5 meters), with intervals of 5 meters between segments to ensure reliability in data calculation. Record bottom components under the transect line at points spaced 0.5 meters apart, starting from 0 meters, 0.5 meters, 1 meter, 1.5 meters... up to 19.5 meters. Once the 19.5-meter point is completed, the first of the four segments of the 100-meter transect line is finished, skipping the 20 - 24.5 meters interval. Repeat this process for 25 - 44.5 meters, 50 - 69.5 meters, 75 - 94.5 meters, skipping the 20 - 24.5 meters, 45 - 49.5 meters, 70 - 74.5 meters, and 95 - 100 meters intervals. Record bottom components into the data sheet using symbols as indicated on the bottom component recording sheet. Ten bottom components need to be recorded including: hard coral (HC), soft coral (SC), dead coral (DC), rock (RC), coral rubble (RB), sand (SD), mud (SI), large seaweed (FS), sea anemones (SP), and other organisms (OT);

7. Marine Fish;

a) Sampling on Coral Reefs;

- Rapid assessment of reef fish resources through direct observation statistics combined with underwater filming and photography:

+ Survey Location Selection: Conduct a general survey of the reef slope (type, distribution, etc.), select survey points representative of the entire reef. All sites must be similar in physical characteristics, slope, and coral cover. In clear water, use the manta tow method for a general survey, otherwise apply the point diving method for high turbidity reef areas. Select at least two points (repeated) facing the prevailing wind direction to calculate changes within a habitat. Each site within a habitat (windward slope) must be similar to other windward sites. If there are distinct windward and leeward habitats, choose at least one or two sites in each area. In regions opposite the prevailing winds, select sites in reef areas facing different seasonal winds. Sites within habitats should be separated by an appropriate distance (from 100 to 200 meters);

+ General Procedures: Species must dominate in number, not have cryptic habits, be easily identifiable underwater, and be closely associated with reef slope habitats;

+ Transect Placement: At each reef site, place at least two 50-meter transects at depths of 3 - 5 meters and 8 - 10 meters. These transects are used for both benthic life surveys (LIT). It is advisable to conduct surveys of both fish and benthic life on the same reef;

+ Survey Techniques: The survey time is conducted between 8:30 AM and 3:30 PM to ensure adequate sunlight on the reef and avoid counting nocturnal feeding groups. After laying out the transect lines, wait 5 to 15 minutes, remain quiet until fish return to normal behavior before counting. Each transect is surveyed as a 50 x 5-meter belt. The observer (using diving equipment) swims slowly along the transect, recording all encountered fish species within a 2.5-meter width (density, total length estimated, and identification to species level) on both sides and 5 meters above the transect. Always check the diver's ability to determine the 5-meter width before starting the survey. In poor visibility, the transect width may be reduced to 2.5 meters and the height above the transect to 2.5 meters;

- The repeated monitoring method evaluates the fluctuation of reef fish resources using the Reef Check method.

+ Selection of survey site: Depending on the monitoring purpose, we choose different coral reef sites. Select a coral reef area with a length of at least 100 meters to set up cross-sections. Describe the selected site with necessary parameters such as latitude and longitude, distance from shore, distance from river mouth, distance from the nearest residential area, pollution level, and reasons for selecting this location;

+ Arrangement of cross-section ropes: The number of cross-section ropes usually placed is two and they are parallel to the depth contour lines, one on the flat part of the reef at depths of 3 - 6 meters and another on the sloping part of the coral reef at depths of 6 - 12 meters. Recheck to avoid the situation where the cross-section rope floats on the water surface. Use two buoys floating on the water surface tied to each end of the cross-section rope to mark the position. The length of a cross-section is 100 meters (the cross-section is a measuring tape divided into minimum intervals of 0.5 meters) divided into four smaller sections (0 - 20 meters, 25 - 45 meters, 50 - 70 meters, and 75 - 95 meters), each section being 20 meters long to ensure reliability during data calculation process;

+ Survey technique: About 10 - 15 minutes after laying out the cross-section (waiting for the water to calm down again), the fish observer will conduct observations, swimming slowly and starting to count the number of relevant indicators (listed in the method) along the cross-section within a range of 2.5 meters on either side of the rope, 5 meters ahead and 5 meters above from the starting point (i.e., the 0-meter point) to the 5-meter point. Stop at the 5-meter point for 3 minutes to wait for fish to move out of their hiding places before continuing to count in the next 5 - 10 meters. Stop for 3 minutes and then count in the next 10 - 15 meters, followed by counting in the 15 - 20 meters range. This process continues similarly for the remaining sections (25 - 45 meters, 50 - 70 meters, and 75 - 95 meters) without counting in the 20 - 25 meters, 45 - 50 meters, 70 - 75 meters, and 95 - 100 meters ranges;

- Indicators recorded for coral reef fish include: Groupers, Snappers, Seetlips, Emperors, Butterflyfishes, Barramundi cod, Bumphead parrotfish, Humpheadfish, and various species of Morray eels;

b) Sampling method for coastal waters

- Selection of survey site: Choose a sampling site that is representative of the area and ensures comparability;

- Sampling technique: Use multiple types of nets simultaneously for sampling. The type of net used for sampling depends on the target species and the appropriate habitat for operating that type of net. Along areas transitioning between habitats, such as mangrove forests/seagrass/coral reefs, additional horizontal nets should be used to sample fish moving between habitats. Record all details about the collected samples (sampling location (GPS coordinates), type of sampling net, number of net pulls, time of pulling);

- Samples are fixed in plastic boxes, large PP containers with lids, PVC bags, or equivalent equipment. Small fish samples are typically preserved in 10% formalin solution, while larger specimens are preserved in 20% formalin solution. Collected samples need to be classified into taxa and preliminarily identified before being taken back to the laboratory;

8. Mangrove plants

a) Sample collection work:

- Establish cross-sections in the study area. At least two cross-sections are set up in the research area. Cross-sections must reflect the structural characteristics of the plant community in the area. At each research station, establish at least three cross-sections running perpendicular to the shoreline and cutting across the mangrove vegetation;

- Divide the cross-section into zones: low tide, mid-tide, and high tide to study the structure of the mangrove plant community;

- Depending on the composition of mangrove plant species, typical forest types may be distinguished;

- Randomly place three identical quadrats along the cross-section rope. Collect qualitative samples (collect leaves, flowers, fruits, etc., to determine the scientific name of the species). Collect quantitative samples (quantitative quadrats used to determine the density and ecological indices of mangrove plants are usually 10 meters x 10 meters or larger);

- In some cases (time limitations, natural conditions, or other factors), smaller quadrats may be used but the data must still ensure statistical significance (each quadrat must contain at least 40 - 100 individuals);

- Count the number of trees in the quadrat (including those with trunks inside the quadrat), measure the length and diameter of the trees, identify the species composition within the quadrat, and calculate the proportion and density of species in the quadrat. b) Preservation and transportation of samples:

- After collecting, samples are soaked in alcohol, then pressed using a press frame in newspapers and packed in foam boxes, wooden crates, or large PP containers with lids clearly labeled for transport to the laboratory;

- Specimen processing method: Collected samples are dried (with sulfur treatment) at temperatures ranging from 40°C to 105°C for 24 hours;

c) Sample analysis: Identify to genus and subspecies.

Article 34. Processing Data and Reporting Results

1. Analytical Indicators

a) Species composition;

b) Biomass (determine density and weight or other indices).

2. Data Editing

a) Input survey and investigation data into an Excel file or suitable software. Create analysis tables;

b) Calculate data: Determine natural reserves, diversity, similarity, balance, richness indices, calculate coverage of mangrove plants, bottom animals, fish, sea grasses, seaweed, coral;

c) Draw charts and graphs with specialized computer software support;

d) Draw distribution maps of resources: Use mapping software such as Mapinfo, ArcGIS and other types of software;

đ) Prepare reports on investigation and survey results.

Article 35. Inspection and Acceptance

1. Inspect the volume of work performed, assess and evaluate the quality of the results achieved from the survey.

2. Evaluate the collected data set. Compare and contrast with the general laws of the research area.

3. Organize reports on results, summarize, and draw lessons for subsequent survey trips.

Article 36. Submitted Products

1. Survey and investigation result data sets. Field diaries, specimens, analysis results, maps, charts, and distribution diagrams of marine ecological factors.

2. Summary report evaluating and providing preliminary comments on the results obtained during the marine ecological survey.

3. Recommendations and proposals for future marine ecological surveys, identifying areas to be surveyed and frequency of implementation to meet task requirements.

Chapter III

HANDLING INCIDENTS AND LABOR SAFETY REGULATIONS

Article 37. Incident Handling

During marine and coastal environmental surveys and investigations, when encountering incidents that endanger people and equipment, the following must be adhered to:

1. For survey and investigation participants

a) In case of minor work-related accidents on board, immediate first aid should be provided;

b) In serious cases, the victim must be immediately transferred to shore and taken to the nearest medical facility.

2. For survey and investigation vessels

a) In case of encountering typhoons, tropical depressions, high waves, strong winds that do not ensure safety for ships, equipment, and personnel, find safe places to shelter;

b) In case of incidents such as fire, explosion, leakage, and other incidents, immediate rescue and on-site handling must be carried out. If it cannot be resolved, immediately report to the competent authority via radio waves.

3. For survey and investigation equipment

a) When encountering technical issues, they must be repaired immediately. If it cannot be fixed at sea, a backup machine must be used;

b) Damaged equipment must be brought ashore for inspection and repair to ensure quality and progress of the work.

Article 38. Labor Safety Regulations

1. For survey and investigation participants

a) All technical staff and workers must attend labor safety training courses;

b) Personal protective equipment must be used fully and correctly as prescribed;

c) Alcohol, tobacco, and other stimulants must not be used during work;

d) Adhere to labor safety regulations as stipulated by law.

2. Survey and investigation vessels must comply strictly with current maritime safety regulations.

3. Use machinery, equipment, and materials in surveys and investigations safely and in accordance with technical standards.

Chapter IV

IMPLEMENTING PROVISIONS

Article 39. Effective date

This Circular takes effect from January 27, 2025 and replaces Circular No. 34/2010/TT-BTNMT dated December 14, 2010 of the Minister of Natural Resources and Environment on technical guidelines for marine hydrographic, chemical, and environmental surveys in coastal areas and islands.

Article 40. Transitional Provisions

Specialized tasks and projects approved according to the provisions of Circular No. 34/2010/TT-BTNMT and being implemented or yet to be implemented before this Circular takes effect shall continue to be implemented based on the approved bases, except where there is a requirement to implement according to the provisions of this Circular.

Article 41. Implementation Organization

2. In case the legal normative documents cited in this Circular are amended, supplemented, or replaced, they shall be implemented according to the new amended, supplemented, or replaced documents.