scholarly journals Assessment of impact of fishing on Indian mackerel Rastrelliger kanagurta (Cuvier, 1816) in Tuticorin, south-east coast of India

2016 ◽  
Vol 63 (3) ◽  
Author(s):  
M. Sivadas ◽  
S. Mohamed Sathakkathullah ◽  
K. Suresh Kumar ◽  
K. Kannan
Keyword(s):  
East Coast ◽  
Growth Equation ◽  
Continuous Increase ◽  
Indian Mackerel ◽  
F Factor ◽  
Stock Biomass ◽  
Spawning Stock ◽  
Second Year ◽  
Rastrelliger Kanagurta ◽  
Von Bertalanffy Growth Equation

Fishery of the Indian mackerel Rastrelliger kanagurta (Cuvier, 1816) from Tuticorin was studied for the period 2011-2014. Indian mackerel formed fishery round the year in Tuticorin with peak during June to November in trawl and October to December in gillnet. The annual catch varied from 1650 to 5101 t (average 2968 t) in gillnet and from 815 to 1716 t (average 1231 t) in trawl. Total length (TL) of the fishes ranged from 10 to 30.5 cm. Length-weight relationship estimated was W = 0.0038777*L3.3 (r2 = 0.99, n = 535, L=TL in cm, W in g). The fishes were found to be continuous spawners with peak spawning during January to August and November. The von Bertalanffy growth equation derived was Lt = 31.2 [1-e -1.3(t+t0)]. The species attained TL of 22.7 cm in 12 months and 28.9 cm by the end of second year. Longevity estimated was 2.3 years, Phi-prime index (ᴓ) was 7.143, while Z and M were 4.36 and 2.132 respectively. Thompson and Bell model showed continuous increase of yield even after considerable rise in F-factor. Spawning stock biomass (SSB) was 79% at an f-factor of 3.5. F0.1 using Beverton and Holt Y/R model was 3.4 whereas the present F was 2.23 indicating that the current level of fishing is not affecting the stock adversely.

Growth, mortality and exploitation of bigeye scad, Selar crumenophthalmus off Mumbai, north-west coast of India

2015 ◽  
Vol 96 (7) ◽  
pp. 1411-1416 ◽  
Author(s):  
Debabrata Panda ◽  
A. K. Jaiswar ◽  
Soma Das Sarkar ◽  
S. K. Chakraborty
Keyword(s):  
West Coast ◽  
Performance Index ◽  
Single Pulse ◽  
Mortality Rates ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
North West ◽  
Second Year ◽  
Von Bertalanffy Growth Equation

An investigation was carried out to study the growth, mortality and exploitation of bigeye scad, Selar crumenophthalmus off the Mumbai coast during September 2008 to August 2009. The von Bertalanffy growth equation was derived as Lt = 310 mm [1−exp {−1.4 year−1 × (t−(−0.059 year))}] with the growth performance index (ø’) of 3.13. The fishable lifespan of the species was 2+ years in Mumbai waters. Bigeye scad attains total length of 240 and 293 mm during its first and second year of life. The size at first capture (Lc) was estimated as 240 mm (1+ year). The recruitment was continuous and throughout the year with a single pulse during August. Nearly 50% of the recruitment took place during August and September. The total, natural and fishing mortality rates were 4.62, 2.21 and 2.41 year−1, respectively. The estimated exploitation ratio (0.52) was very close to the optimum value of 0.5. Hence, the stock can be considered as optimally over-exploited in Mumbai waters.

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

scholarly journals A two-stage biomass model to assess the English Channel cuttlefish (Sepia officinalis L.) stock

2014 ◽  
Vol 71 (9) ◽  
pp. 2457-2468 ◽  
Author(s):  
Michaël Gras ◽  
Beatriz A. Roel ◽  
Franck Coppin ◽  
Eric Foucher ◽  
Jean-Paul Robin
Keyword(s):  
Reference Points ◽  
Sea Surface ◽  
Sepia Officinalis ◽  
Sustainable Utilization ◽  
English Channel ◽  
Two Stage ◽  
Stock Biomass ◽  
Exploitation Rate ◽  
Spawning Stock ◽  
Age Structured

Abstract The English Channel cuttlefish (Sepia officinalis) is the most abundant cephalopod resource in the Northeast Atlantic and one of the three most valuable resources for English Channel fishers. Depletion methods and age-structured models have been used to assess the stock, though they have shown limitations related to the model assumptions and data demand. A two-stage biomass model is, therefore, proposed here using, as input data, four abundance indices derived from survey and commercial trawl data collected by Ifremer and Cefas. The model suggests great interannual variability in abundance during the 17 years of the period considered and a decreasing trend in recent years. Model results suggest that recruitment strength is independent of spawning–stock biomass, but appears to be influenced by environmental conditions such as sea surface temperature at the start of the life cycle. Trends in exploitation rate do not reveal evidence of overexploitation. Reference points are proposed and suggestions for management of the sustainable utilization of cuttlefish in the English Channel are advanced.

Modelling the effects of establishing a marine reserve for mobile fish species

2002 ◽  
Vol 59 (3) ◽  
pp. 405-415 ◽  
Author(s):  
P Apostolaki ◽  
E J Milner-Gulland ◽  
M K McAllister ◽  
G P Kirkwood
Keyword(s):  
Fish Species ◽  
Marine Reserve ◽  
High Mobility ◽  
Merluccius Merluccius ◽  
Seasonal Movements ◽  
Stock Biomass ◽  
Spawning Stock ◽  
Short And Long Term ◽  
Immature Fish

We present a model of the effects of a marine reserve on spawning stock biomass (SSB) and short- and long-term yield for a size-structured species that exhibits seasonal movements. The model considers the effects of protecting nursery and (or) spawning grounds under a range of fishing mortalities and fish mobility rates. We consider two extremes of effort redistribution following reserve establishment and analyze the effects of a reserve when the fishery targets either mature or immature fish. We apply the model to the Mediterranean hake (Merluccius merluccius) and show that a marine reserve could be highly beneficial for this species. We demonstrate benefits from reserves not just for overexploited stocks of low-mobility species, but also (to a lesser extent) for underexploited stocks and high-mobility species. Greatly increased resilience to overfishing is also found in the majority of cases. We show that a reserve provides benefits additional to those obtained from simple effort control. Benefits from reserves depend to a major extent on the amount of effort redistribution following reserve establishment and on fishing selectivity; hence, these factors should be key components of any evaluation of reserve effectiveness.

scholarly journals Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates?

2012 ◽  
Vol 69 (8) ◽  
pp. 1448-1456 ◽  
Author(s):  
Anna Gårdmark ◽  
Örjan Östman ◽  
Anders Nielsen ◽  
Karl Lundström ◽  
Olle Karlsson ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Halichoerus Grypus ◽  
Grey Seal ◽  
Older Individuals ◽  
Standard Assessment ◽  
Abundance Estimates ◽  
Stock Biomass ◽  
Key Species ◽  
Spawning Stock ◽  
Bothnian Sea

Abstract Gårdmark, A., Östman, Ö., Nielsen, A., Lundström K., Karlsson O., Pönni, J., and Aho, T. 2012. Does predation by grey seals (Halichoerus grypus) affect Bothnian Sea herring stock estimates? – ICES Journal of Marine Science, 69: . Mortality of small pelagic fish due to marine mammals is generally considered to be low compared with other sources of mortality. With recent recoveries of marine mammal predators worldwide, this may no longer hold. The grey seal (Halichoerus grypus) population in the Bothnian Sea has increased fivefold since 1985. Its main prey, herring (Clupea harrengus), is a key species for fisheries in the region. Yet, current stock assessments assume constant natural mortality, leading to a risk of biased stock estimates with increasing predation and misleading analyses of herring population dynamics. We estimated grey seal predation from diet data and reanalysed herring spawning stock biomass (SSB) during 1973–2009. Accounting for predation increased the herring SSB 16% (maximum 19%), but this was within the confidence intervals when ignoring predation. Although mortality in older individuals was inflated when accounting for seal predation, this did not change the conclusions about drivers of herring dynamics. Accounting for grey seal predation is important for abundance estimates of old herring, but currently not for SSB estimates, given the great uncertainties in the standard assessment. The grey seal impact on Bothnian Sea herring will need to be reassessed if stock age composition, grey seal feeding preferences, or total stock development change.

scholarly journals Somatic growth and age of selected commercial fish species of the Cullera Coast, Iberian Peninsula, south-east Spain

2019 ◽  
Vol 66 (3) ◽  
Author(s):  
Angela Maria Jaramillo-Londono ◽  
Alejandra Vanina Volpedo ◽  
Jose Luis Diaz-Arevalo ◽  
Maria Eugenia Rodrigo-Santamalia ◽  
Vicent Bendito-Dura
Keyword(s):  
Fish Species ◽  
Somatic Growth ◽  
Mesh Size ◽  
Age And Growth ◽  
Biological Information ◽  
Growth Equation ◽  
Commercial Fish ◽  
Mullus Surmuletus ◽  
Von Bertalanffy Growth Equation ◽  
Uranoscopus Scaber

This work provides data on the somatic growth and age of selected commercial fish species of the Cullera Coast, Spain. The biological information available that permits responsible fishing management of these species is relatively scarce. This study was conducted in the Bay of Cullera, Spain (39º 12’to 38º 59’N, and 0º 09’to 0º 15’W); and selected benthic fish species were analysed that are frequently fished by trammel nets (mesh size 28-76 mm) at a maximum depth of 30 m. Maturity , age and growth of 63 torpedoes, Torpedo torpedo (L., 1758), 115 red scorpionfish, Scorpaena scrofa Linnaeus, 1758, 280 red mullets, Mullus surmuletus Linnaeus, 1758, 139 stargazers, Uranoscopus scaber Linnaeus, 1758, and 476 Portuguese soles, Dagetichthys lusitanicus de Brito Capello, 1868 were analysed. The data obtained in this study revealed that 50% of individuals of all the species reached sexual maturity at a TL (total length) of 20.0-36.5 cm and at an age of 2-6 years. The von Bertalanffy growth equation derived were: TL=37.0 (1 - e(-0.2(t + 0.33))); TL =31.5(1 - e(-0.38(t + 0.54))); TL =35.5(1 - e(-0.2(t + 2.08))); and TL =34.3(1 - e(-0.14(t + 2.16))) for S. scrofa, M. surmuletus; U. scaber and D. lusitanicus respectively.

Biomedical applications of fish gut associated Streptomyces maritimus IM20 isolated from Rastrelliger kanagurta (Indian mackerel)

2021 ◽  
Vol 16 (10) ◽  
pp. 120-130
Author(s):  
Angamuthu Vignesh ◽  
Venugopal Gopikrishnan ◽  
Sivaraj Anbarasu ◽  
Manikkam Radhakrishnan ◽  
Joseph Jerrine
Keyword(s):  
Ethyl Acetate ◽  
Ethyl Acetate Extract ◽  
Radical Scavenging ◽  
Bioactive Metabolites ◽  
Molecular Characteristics ◽  
Inhibition Assay ◽  
Indian Mackerel ◽  
Fish Gut ◽  
Rastrelliger Kanagurta

The biomedical potential of fish gut-associated actinobacteria isolated from the marine fish Rastrelliger kanagurta (Indian mackerel) was investigated. The actinobacterial strain IM20 was isolated from the fish gut by using Kusters agar medium prepared with 50% sea water. Based on their phenotypic and molecular characteristics, strain IM20 was identified as Streptomyces maritimus. The bioactive metabolites produced from the strain IM20 by agar surface fermentation and ethyl acetate extraction were tested for in vitro antimicrobial, antiquorum sensing , anti-biofilm, anti TB, anti-oxidant and anti-cancer activity. The MIC value of ethyl acetate extract (EAE) of IM20 was found to be 16 μg ml−1 against S. aureus and E. coli. In quorum sensing inhibition assay, the extract showed violacein inhibition upto 87% at 512 μg ml−1 concentration when tested by pigment inhibition assay using C. violaceum MTCC 2656. The results of in vitro assays revealed that the ethyl acetate extract of IM-20 (EAE-IM20) showed 75%, 83% and 72% inhibition against Mycobacterium tuberculosis H37Rv, M. tuberculosis (SHRE sensitive) and multi drug resistant (MDR) M tuberculosis respectively at 500 μg ml−1 concentration. In DPPH assay, 71% radical scavenging activity was exhibited by the EAE-IM20 at 250 μg ml−1. In MTT assay, EAEIM20 exhibited 74.29±2.01% inhibition on breast cancer cell line MCF7 (250 μg ml−1). This study broadly determines that the fish associated actinobacteria is a prolific place for diverse multifunctional bioactive compounds for the development of medically important unique drugs.

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