| General Information: |
| Title: | Monitoring of seagrass along southern Andaman coast of Thailand |
| Identifier: | ERDP-2020-10.1.1 |
| Abstract: |
Seagrass ecosystems provide various important ecosystem services in the marine environment. However, their global distribution has been declining since the 1800s. At the current rate of decline of almost 1.5% per year, almost half the meadows will be lost in the next 100 years. To prevent or minimize their loss, global monitoring programs have been established, such as SeagrassNet. The aim of the program is to introduce a global monitoring protocol and to preserve seagrass ecosystems by increasing scientific knowledge of them. The aim of this study was to gather data obtained by this protocol and to set a baseline for knowledge of the seagrass meadows in marine national parks in Southern Thailand. The data were collected from February 2006 until March 2009, three times a month at three national parks: Haad Chao Mai, Tarutao and Mu Ko Petra. At each site the data were obtained along three transects parallel to the coast with 12 quadrats, in which species coverage and biomass above and below ground were recorded. These data sets can be used in future seagrass health assessments, in observation of the temporal changes of the meadows and as a baseline for restoration efforts.
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| Keywords: |
- Marine Plants
- Biomass
- Coverage
- SeagrassNet
- Southeast Asia
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Involved Parties
| Data Set Owners: |
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Organization: | Seaweed and Seagrass Research Unit and SeagrassNet |
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| Data Set Contacts: |
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Individual: | Ekkalak Rattanachot |
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Organization: | Seaweed and Seagrass Research Unit, Excellence Center for Biodiversity of Peninsular Thailand, Faculty of Science, Prince of Songkla University |
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Address: |
| Hat Yai, |
| Songkhla, Thailand |
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Email Address:
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| Associated Parties: |
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Individual: | Ekkalak Rattanachot |
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Organization: | Seaweed and Seagrass Research Unit, Excellence Center for Biodiversity of Peninsular Thailand, Faculty of Science, Prince of Songkla University |
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Address: |
| Hat Yai, |
| Songkhla, Thailand |
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Individual: | Milica Stankovic |
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Organization: | Seaweed and Seagrass Research Unit, Excellence Center for Biodiversity of Peninsular Thailand, Faculty of Science, Prince of Songkla University |
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Address: |
| Hat Yai, |
| Songkhla, Thailand |
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Individual: | Piyalap Tuntiprapas |
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Organization: | Seaweed and Seagrass Research Unit, Excellence Center for Biodiversity of Peninsular Thailand, Faculty of Science, Prince of Songkla University |
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Address: |
| Hat Yai, |
| Songkhla, Thailand |
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Individual: | Anchana Prathep |
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Organization: | Seaweed and Seagrass Research Unit, Excellence Center for Biodiversity of Peninsular Thailand, Faculty of Science, Prince of Songkla University |
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Address: |
| Hat Yai, |
| Songkhla, Thailand |
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Data Set Characteristics
| Geographic Region: |
| Geographic Description: | The sites are distributed along the lower Andaman (west) coast of Thailand, in Trang and Satun provinces |
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Bounding Coordinates:
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| West: | 99.30968944 degrees
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| East: | 99.690585 degrees
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| North: | 7.38279416 degrees
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| South: | 6.60488916 degrees
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Sampling, Processing and Quality Control Methods
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Step by Step Procedures
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| Step 1: |
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Description:
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Study sites
Seven sites were set up in intertidal seagrass meadows along the coast of the Southern Andaman Sea, on the western seaboard of peninsular Thailand (Figure 1a). Two sites were selected in Trang province in the area of Haad Chao Mai National Park (Figure 1b): Laem Yong Lam (HCM NP Site 1) (7° 22.975 N, 99° 20.129 E) and Mook Island (HCM NP Site 2) (7° 22.591 N, 99° 18.617 E). Another five sites were selected in Satun province: three in Mu Ko Petra National Park (Figure 1c) at Lidee Lek (Petra NP Site 1, 6º 46' 58.2" N, 99º 46' 10.8"E), Lidee Yai site 1, (Petra NP Site 2, 6º 46' 58.7" N, 99º 46' 52.2" E) and Lidee Yai site 2 (Petra NP Site 3, 6º 47' 11.9"N, 99º 46' 40.9" E); and two at Talowaw Bay on Tarutao Island, Tarutao National Park (Figure 1d): (Tarutao Site 1, 6º 36' 20.6" N, 99º 41' 25.3" E and Tarutao Site 2, 6º 36' 45.2" N, 99º 41' 14.4").
Monitoring started in February 2006 at HCM NP Sites 1 and 2, in June 2006 at Petra NP Sites 1, 2 and 3 and in February 2007 at Tarutao NP Sites 1 and 2. Data were collected three times a month, but due to severe weather conditions, especially during monsoon season, data were not collected from some sites (please refer to the missing_data_table.csv to see the overview and explanation of the missing data, check Table 2 and 3 for the description of the file and variables). Data collection and site monitoring ended in 2009.
Figure 1: (a) Location of the study sites (shaded areas) along west coast of Thailand; (b) Sites at Haad Chao Mai National Park; (c) Sites at Mu Ko Petra National Park; (d) Sites at Tarutao National Park; (e) Arrangement of the transects towards the land and location of screw anchors
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| Step 2: |
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Description:
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Field collection
The study was carried out following the SeagrassNet protocol (Short et al. 2006b; www.seagrassnet.org). Three transects (50 m) were laid parallel to the shore (Figure 1e). The first transect (transect A) delineated the upper edge of the seagrass meadows, the second transect (transect B) delineated the transitional zone between the shallow edge and the deeper edge and the third transect (transect C) delineated the deeper edge of the meadows. Three steel screw anchors were permanently placed in the substrate at 0, 25 and 50 m of each transect and were used as station markers for the duration of the study. The GPS coordinates of each anchor were recorded during setup. If a station marker was lost, the pre-recorded GPS points were used to reinstall the marker at the next field collection (for the detailed description of the sites and transects please check sites.csv file and Table 2 and 3 for detailed description of the variables). To assess seagrass abundance, 12 quadrats (50 × 50 cm) were randomly placed along each transect on the landward side, and species composition, percent coverage of each species (%) and total percent coverage (%) were recorded.
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| Step 3: |
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Description:
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Species identification
Seagrass species were identified following previous study in Thailand by Lewmanomont and Ogawa 1995 and the information in SeagrassNet manual (Short et al., 2006b), which used mainly vegetation parts such as leaf morphology as the key character (complete list of the species is in Table 1 and codes for the species is in Table 4). There were 2 species in the genus Halodule (H. uninervis and H. pinifolia) and 2 species in the genus Halophila (H. ovalis and H. minor) that sometimes have unclear character. The following characters are used to identify these species. Halolude uninervis was distinguished from H. pinifolia by the tridentate leaf tip with well-developed lateral teeth, while the latter species has obtuse tip with irregular teeth. Halophila ovalis was distinguished from H. minor by the bigger leaf blade (3-8 mm wide) and 12-19 pairs of cross veins, while the latter species has smaller leaf blade (3-4.5 mm wide) with 6-8 cross veins (Lewmanomont and Ogawa 1995). In addition, the species identification was also confirmed from the specimens collected for biomass.
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| Step 4: |
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Description:
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Biomass collection
Seagrass biomass was collected by core sampler (7 cm in diameter). Biomass was collected outside the coverage estimation area (0.5 m to the landward side of transects) from areas of similar coverage and species composition to the quadrat. Biomass was only collected for species which had coverage higher than 5%. Whole plants including leaves, rhizomes and roots were collected and as much sediment was scraped off as possible. Biomass samples were packed in labeled bags and kept in a cool, dark container until arrival at the laboratory.
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| Step 5: |
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Description:
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Data processing
At the laboratory, seagrass specimens were cleaned by washing with fresh water. Epiphytes were removed by scraping with a brush or razor blade and if calcareous epiphytes presented, plants were soaked in weak acid (vinegar) then scraped and rinsed with fresh water again.
Plants were separated into above- (leaf blade, leaf sheath and petiole) and below-ground biomass (rhizome and root). Biomass parts were separately dried in a hot air oven at 60°C until constant weight was obtained. Biomass data were calculated to grams dry weight per square meter (g m-2) for each part and species.
The collected data were saved to site-specific files. As biomass was not collected of species with a coverage less than 5%, coverage information about these species was omitted in the data file. If some samples were lost during transportation or could not be collected due to severe monsoon weather, NAs were used instead. For further information about the missing data at each of the site, please refer to the missing_data_table.csv.
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Data Set Usage Rights
| This dataset is provided under a Creative Commons Attribution 4.0 International License (CC BY 4.0; https://creativecommons.org/licenses/by/4.0/legalcode). |
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