Document Type : (original research)
Fisheries Department, Faculty of Marine Science, Chabahar Maritime University, Chabahar, Iran
Fisheries Department, Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran
2- Fisheries Department, Faculty of Marine Science &Technology, University of Hormozgan, Bandar Abbas, Iran.
The present study aimed to identify the species composition and estimate by-catch rates in fixed gillnet for Otolithes ruber in the Chabahar coastal waters (Pozm fishing port) for seven months (from October 2019 to April 2020). Fishing and sampling operations were performed by active boats equipped with 10-12 panels fixed monofilament gillnets for O. ruber with a mesh size of 73 mm from knot to opposite knot (STR) and the length and height of the net are 182.88 and 7.74 meter, respectively. Overall, target species had the highest frequency with 27.66%, followed by Pomadasys kaakan (12.23%), Saurida tumbil (10.98%), Netuma thalassinus (7.45%), Ephippus orbis (6.32%) and Nemipterus japonicas (5.41%) had the highest. Catch per unit effort for O. ruber (4.46 number / panel.day) and (3010.02 g / panel.day) calculated. The weight ratio of target catch to by-catch was 1 to 2.6. Also, 14.09% of the total catch was discarded that catfish accounted for 52.84% was the most frequency among the discard species. Comparison of the length frequency of caught fish samples with the Lm50 value reported for this fish in the area (40 cm) shows that 56.64% of the caught samples are below the standard size and the size of the net mesh used is not suitable for O. ruber fishing. Therefore, standardization of gill nets should be considered by observing requirements such as determining the appropriate size of the net mesh to catch the target species and using the appropriate yarn number.