Akademik Veri Yönetim Sistemi
3rd International Aquatic Biotechnology Symposium, İstanbul, Türkiye, 25 - 27 Eylül 2024, ss.43-44, (Özet Bildiri)
Nowadays,
as the negative effects of climate change are more frequently seen in the
marine environment, the leaves and stem parts of Posidonia oceanica, an
endemic species of the Mediterranean, as well as the mat and underlying
sediment layers have become the subject of new research. The objectives of our
TUBITAK 123Y368 project, which started in 2024, include detecting and mapping
the distribution of P. oceanica meadows with side scan sonar data,
determining the mat thickness of the meadows from and high resolution shallow
seismic and determining the approximate mat volume by determining how much area
they are spread under the bottom, as well as determining the general values of
physical parameters (temperature, salinity, etc.) affecting the locations where
meadows and mats are distributed.
Within
the scope of the project, side scan sonar data were collected with CMAX CM2 and high resolution shallow seismic (CHIRP) data were
collected with Syqwest Bathy 2010P in the study area in Karaburun-Ildır Special
Environmental Protection Area. In addition, seawater temperature and salinity
data were recorded with Microcat CTD at designated points in the area. In
addition, verification of possible Posidonia meadows seen in the sonar
data was carried out by video imaging with an underwater drone and photography
with GoPro.
In
the preliminary results, the mat structure observed in the seismic data is
differentiated by the high acoustic impedance difference with the underlying
stratigraphic unit. The internal reflection has a medium-low amplitude
quasi-parallel reflection. In sonar data, seagrass meadows show continuous
strong texture reflection with isolated bright areas in dense areas and
continuous strong texture reflection with abundant isolated bright areas in
sparse areas. Underwater drone video imaging on a line to the south of the
study area shows that the current Posidonia is sparse at 25m and is not
observed after 27m. At 32m, where the mat ends, Posidonia is absent from
the current seabed. This relationship suggests that the mat defined in these
areas is a mat structure belonging to Posidonia in the past. In the
physical oceanography studies, seawater temperature values measured at the
selected points ranged between 19.23°C and 25.07°C, while salinity values were
realized between 39.08 psu and 39.99 psu. The presence of the expected
two-layer structure and thermocline in the summer months was also observed from
the vertical temperature distributions throughout the study.
Keywords: Posidonia Oceanica, Side
Scan Sonar, High Resolution Shallow Seismic, Underwater Imaging, Physical
Parameters