केंद्रीय समुद्री मात्स्यिकी अनुसंधान संस्थान का वेरावल अनुसंधान केंद्र

केंद्रीय समुद्री मात्स्यिकी अनुसंधान संस्थान का वेरावल अनुसंधान केंद्

Thompson & Bell prediction model

Prediction or predictive models predict the effect of different levels of fishing effort on the fish stocks in the future. Two prediction models that are widely applied are Thompson and Bell (1934) model and the Yield per recruit model developed by Beverton and Holt (1957). These models provide a direct link between fish stock assessment and fishery resource management. The Thompson & Bell Model is a widely used prediction model in assessing the optimum factor for increase or decrease of fishing effort to achieve maximum sustainable and economic yield of a commercially exploited species. This model builds on the output of age (as conceived in the original model) or length-based Virtual Population Analysis (VPA). The equations used for the VPA and cohort analysis can be transformed to predict future yields and biomass at different levels of fishing efforts; i.e., the knowledge of the past fishery can be used to predict the future yields

गुजरात के मछुआरों द्वारा समुद्री मात्स्यिकी संपदाओं का परिरक्षण और पबंधन

कृपया पूरा लेखा पढ

Protonibea diacanthus (Lacepède, 1802)

Snout is pointed with large terminal mouth forming a low angle to the horizontal. Teeth are differentiated into large and small in both jaws. No canine teeth present. Lower gill rakers are 7 to 8. Dorsal fin spines are 9-10 followed by low notch and are with 22-24 soft rays. Pectoral fin is fairly small, a little more than half of the head. Anal fin is with 2 spines and seven soft rays. The second anal spine is strong. Rhomboid shaped caudal fin

Parastromateus niger (Bloch, 1795)

Body is rhomboid, scaly, strongly compressed and deep grey-brown to dark grey in colour. The head is blunt with a terminal mouth. Both dorsal and anal fins are triangular. The sickle-shaped slender pectoral fin extends beyond mid-body. A number of small scutes are present on the slender caudal peduncle. Dorsal fin is with 2-6 spines and 41-46 soft rays; anal fin is with 2 spines and 35-40 soft rays. Pelvic fins are absent in fish over 9 cm size

కృత్రిమ దిబ్బల సాగులో ప్రపంచ వ్ ర యాప్తంగా ఆచరించే పద్ధతులు (Global practices in artificial reefs)

Historically, it was well understood by the coastal communities and fisher’s world over that the rock patches, sunken ships and vessels and submerged coastal dwellings and reefs supported more life in the coastal waters, and they supported good fisheries. The floating tree trunks, leaves, floating islands in flash floods carried huge sheltering populations of fishes and fauna. The traditional fishers of Kerala and Tamil Nadu in India deployed huge palm trees and thick bushy trees with foliage as anchors in the sea bottom with boulders and sandbags which harboured larger predatory fishes and thus improving catch rates and returns

Juvenile croakers - a major component of the low value trawl by-catch landed at Chennai

Low value by-catch forms about 10-12% of the trawl landings at Chennai. Fishes form about 60 - 65% of this by-catch. The major fishes occurring in the by-catch include - silverbellies, cardinal fishes, flatheads, lizardfishes, whitebaits anchovies, croakers, threadfin breams, monocle breams, flatfishes, dragonets, glassies, rays and skates, goatfishes, pufferfishes, scorpionfishes etc. Juvenile croakers have been found to occur in considerable proportion in the by-catch

Cephalopod fishery and population dynamics of Loligo duvauceli (Orbigny) off Saurashtra region, Gujarat

The fishery of cephalopods and some aspects of population dynamics of the Indian squid Loligo duvauceli from Veraval and Mangrol in Saurashtra region was studied for the period 1996-99. The average annual landing of cephalopods by trawl in Veraval and Mangrol were estimated at 3911t and 1030t respectively, which contributed 4.8 and 5.7% of the total fish landings in Veraval and Mangrol. Loligo duvauceli dominated the catch (58%) , followed by Sepia aculeata (19%), S. elliptica (19%), S.pharaonis (3%) and Sepiella inermis (1%). The length weight relationship was estimated for males and females of Loligo duvauceli as W= 0.109011 L 2.634609 and W = 0.314656 L 2.185796 respectively. The estimates of VBGF parameters were L! = 303mm and K= 0.98 year -1. The mortality rates values Z, M, F were 3.94, 1.94 and 2.20 respectively. The exploitation rate was 0.56. The present study shows that the resource is exploited above the optimum level and the effort has to be reduced for sustaining the resource for long term exploitatio

On a black porpoise Neophocaena phocaenoides Cuvier landed in a dol net at Seemar, Gujrat

A Black porpoise identified as Neophocaena phocaenoides Cuvier was caught in a dol net operating off Seemar bunder, Gujarat

Global practices in artificial reefs

Historically, it was well understood by the coastal communities and fisher’s world over that the rock patches, sunken ships and vessels and submerged coastal dwellings and reefs supported more life in the coastal waters, and they supported good fisheries. The floating tree trunks, leaves, floating islands in flash floods carried huge sheltering populations of fishes and fauna. The traditional fishers of Kerala and Tamil Nadu in India deployed huge palm trees and thick bushy trees with foliage as anchors in the sea bottom with boulders and sandbags which harboured larger predatory fishes and thus improving catch rates and returns