Page 34 - Abstract book - TJSSF-2020

Thailand – Japan Student Science Fair 2020 (TJ-SSF 2020)
“Seeding Innovations through Fostering Thailand – Japan Youth Friendship”

Mapping of Seagrass Meadows Using Aerial Photography
at Pak Klong Bay in Trang Province, Thailand

It Jubprung , Rattanakon Phlunang
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Advisors: Patchara Pongmanawut , Anantanit Chumsri
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1

Princess Chulabhorn Science High School Trang
1
Rajamangala University of Technology Srivijaya Trang Campus
2

Abstract
There are several factors behind reduction of dugong numbers, and one of the responsible factors is
reduction of seagrass bed. More research should be conducted to know the present status of seagrass
bed in Thailand, as well as to conserve them. Researchers usually observe seagrass beds by sampling
information directly from the field, which is very difficult and time consuming. The aims of this study
are to (1) compare the seagrass coverage between field observation and aerial photography and (2) to
make seagrass mapping at Pak Klong Bay, Trang Province, Thailand. We divided it into three study
areas. Each study area was 30 x 30 meters and divided into 9 points. We surveyed seagrass using field
observation and using drones. Afterwards, calculated the percentage of each seagrass using Wolfram
Mathematica 11.3 program and analyzed the seagrass coverage (%) data using SPSS 22. We found three
seagrass groups in this study: Enhalus acoroides, long flat leaves and short oval leaves. In aerial
photography method using drones, we found 29.04% seagrass (19.48% of long flat leaves, 8.56% of
short oval leaves, and 0.99% of E. acoroides) and in field observation method using quadrats, we found
25.03% seagrass (16.43% of long flat leaves, 8.46% of short oval leaves, and 0.14% of E. acoroides).
There was no significant difference in seagrass coverage between aerial photography and direct field
observation methods. So, drone can be used for checking seagrass bed. This method is easier because
it needs few people, one drone and few hours to finish the study. After that, we surveyed seagrass by
aerial photography using drones to map seagrass at Pak Klong Bay, Trang Province, Thailand. We
found 11.84% seagrass in an area of 22,500 square meters (9.59% of long flat leaves, 2.21% of short
oval leaves, and 0.05% of E. acoroides).

Keywords: Aerial photography, drones, field observation, seagrass coverage

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