First records of bentfin devil ray (Mobula thurstoni) and the examination in physical factors of its habitat in the western waters of Morotai Island (North Moluccas)

Asean-Fen International Fisheries Symposium - 2017

Mukharror, D.A.^1 ; Baiti, I.T.^2 ; Harahap, S.A.^3 ; Prihadi, D.J.^3 ; Ichsan, M.^1 ; Pridina, N.^1

Shark Diving Indonesia Morotai, Kampung Yayasan, Daruba, Morotai, Indonesia^1

FPIK, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang KM 21, Bandung, Indonesia^2

Marine Science Department, FPIK, Universitas Padjdjaran, Jl. Raya Bandung-Sumedang KM 21, Bandung, Indonesia^3

关键词: Conservation management;    Low currents;    Physical factors;    Physical parameters;    Visual census;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/137/1/012048/pdf
DOI  :  10.1088/1755-1315/137/1/012048

来源: IOP

【 摘 要 】

Bentfin devil ray (Mobula thurstoni) was recorded for the first time in Morotai waters on 3rdMarch 2017. In a conservation management context, it is important to clarify the population of Mobula thurstoni and their relations with their habitat. Thus, we examined the existence of Mobula thurstoni with the physical parameters: depth, temperature, visibility, current, weather, and tidal. We measured the existence of Mobula thurstoni with the Underwater Visual Census (UVC) combined with Diver Operated Video (DOV) census. The research from 3rdMarch to 14thJuly 2017 (50 dives) showed the Frequency of Occurence (FO) is 50% per single dive. The highest aggregation of 30 Mobula thurstoni was recorded at 14thMay 2017 and the average sighting was 3.1 Mobula thurstoni per single dive. Among the examined parameters, it was found that strong factor affecting the sighting of Mobula thurstoni were at the depth of 30-35 m, temperature of 30°C, visibility of 16-20 m, low current (