Quantifying vulnerability of sharks and rays species in Indonesia: Is biological knowledge sufficient enough for the assessment?

3rd EMBRIO International Workshop on Marine Biodiversity: Understanding, Utilization, Conservation

生态环境科学

Mardhiah, U.^1 ; Booth, H.^1 ; Simeon, B.M.^1 ; Muttaqin, E.^1 ; Ichsan, M.^1 ; Dharmadi^2 ; Fahmi^3 ; Prasetyo, A.P.^4 ; Yulianto, I.^1^4

Wildlife Conservation Society - Indonesia Program. Bogor, Jawa Barat, Indonesia^1

Center for Fisheries Research, Indonesia Ministry of Marine Affairs and Fisheries, Jakarta, Indonesia^2

Indonesian Institute of Sciences, Jakarta, Indonesia^3

Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, Indonesia^4

关键词: Biological information;    Biological parameter;    euler-lotka equation;    Extinction risks;    Habitat degradation;    Life-history traits;    rays, rmax;    sharks;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/278/1/012043/pdf
DOI  :  10.1088/1755-1315/278/1/012043

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Sharks and rays are vulnerable species, which are highly exploited in Indonesian waters but lacked of detailed information on their ecology and fisheries status. This research aims to assess the level of vulnerability of sharks and rays to overfishing using the maximum intrinsic rate of population increase (rmax), derived from the Euler-Lotka equation, as a proxy of extinction risk. It is calculated based on several biological parameters including fecundity, maximum age, age at maturity, and the number of offspring. Using rmax calculation adapted to shark and ray life history traits by accounting for survival to maturity, we were able to calculate rmax values for 26 out of 208 sharks and rays species present in Indonesia. This includes vulnerable species such as Mobula alfredi, Prionace glauca, and Pristis zijsron. This result showed that rmax is a valuable tool which can be used to quantify extinction risk with some level of precision, but it also highlights the necessity to collect important biological information of the most vulnerable species to further estimate their status. This approach requires complementary information related to external threats such as habitat degradation, species economic value and threat level from local fishing effort and related fishing gears.