سیویلیکا را در شبکه های اجتماعی دنبال نمایید.

Gillnet selectivity of longtail tuna based on morphometric data in Iranina coastal waters in Persian Gulf and Oman Sea

Publish Year: 1396
Type: Conference paper
Language: English
View: 693
این Paper فقط به صورت چکیده توسط دبیرخانه ارسال شده است و فایل کامل قابل دریافت نیست. برای یافتن Papers دارای فایل کامل، از بخش [جستجوی مقالات فارسی] اقدام فرمایید.

نسخه کامل این Paper ارائه نشده است و در دسترس نمی باشد

Export:

Link to this Paper:

Document National Code:

MASERE01_031

Index date: 16 December 2017

Gillnet selectivity of longtail tuna based on morphometric data in Iranina coastal waters in Persian Gulf and Oman Sea abstract

In this study, the size selectivity of long-tail tuna (Thunnus tonggol) was examined for the gillnets of 101, 140 and 132 mm using Sechin model (1969) in Iranian coastal waters of Persian Gulf and Oman sea during the years of 2014-2015. To this aim, the transverse morphometric data for girths in three positions of the fish body such as Opercular girth (OP), girth at the beginning of first dorsal fin (D1) and girth at the beginning of first dorsal fin (D2) as well as fork length were collected by mesh size. Results from Analysis of covariance (ANCOVA) showed that girth at D1 is considered as the maximum girth of the species (SNK: P <0.05). Fish being snagged, depending on the mesh size, were constituted the considerable amount of the catches in the nets depending on the mesh size. Unlike the 114 mm nets, in mesh sizes of 101 and 132 mm the selectivity curves were not fitted to the length frequency distribution, owning to the fish being snagged by larger sizes. According to the selectivity curve, the optimal length of T. tonggol for the nets of 101, 114, and 132 mm was obtained as 41, 50 and 55 cm, respectively. Depending on the mesh size more than 80% of catched juvenile fish are Immature. As well as of target species, bycatch recorded is 26% of the total catches, which is expected to have detrimental effect on the environments. To obtain accurate results, it needs to determine later the size selectivity of long-tail tuna from the data taken from the field experiments of several mesh sizes.

Gillnet selectivity of longtail tuna based on morphometric data in Iranina coastal waters in Persian Gulf and Oman Sea Keywords:

Gillnet selectivity of longtail tuna based on morphometric data in Iranina coastal waters in Persian Gulf and Oman Sea authors

Seyed Abbas Hosseini

Offshore Fisheries Research Center-Chabahar, Agricultural Research Education and Extension Organization (AREEO), Chabahar, Iran

Mohammad Reza Mirzaee

Offshore Fisheries Research Center-Chabahar, Agricultural Research Education and Extension Organization (AREEO), Chabahar, Iran

Siamak Behzady

Persian Gulf and Oman Sea Ecology Research Center, Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Iran