scholarly journals Reproductive Biology of Commercially Valuable Squid, Sepioteuthis lessoniana (Lesson, 1830) Taken as By-Catch in a Tropical Trawl Fishery

2012 ◽  
Vol 4 (4) ◽  
pp. 14-19
Author(s):  
Vellathi VENKATESAN ◽  
Santhanam RAJAGOPAL
Keyword(s):  
Coastal Waters ◽  
Graphical Method ◽  
Gonadosomatic Index ◽  
Mantle Length ◽  
Trawl Fishery ◽  
Management Measures ◽  
Nidamental Gland ◽  
Commercially Important ◽  
Sepioteuthis Lessoniana ◽  
By Catch

Some aspects of the reproductive characteristics of the commercially important squid Sepioteuthis lessoniana (Lesson, 1830) in the coastal waters of Mandapam, Palk Bay was studied with a view to provide possible management measures in this region. A total of 984 individuals (508 males and 476 females) were collected between April, 2009 to March, 2010. The size of specimens ranged from 40 mm to 290 mm in mantle length. Sex ratio was not significantly different from the expected ratio of 1:1 except for months of July, October and December. Spawning season as revealed by seasonal maturity stages, gonadosomatic index of sexes and nidamental gland length (NGL) and dorsal mantle length (DML) ratio of females, lied between January to June with peak at February. Size at maturity as determined by graphical method was 83.5 for males and 112.5 for females.

Aspects of the biology of Caranx bucculentus (Teleostei: Carangidae) from the Gulf of Carpentaria, Australia

1994 ◽  
Vol 45 (3) ◽  
pp. 413 ◽  
Author(s):  
DT Brewer ◽  
SJM Blaber ◽  
DA Milton ◽  
JP Salini
Keyword(s):  
Coastal Waters ◽  
Gonadosomatic Index ◽  
Tropical Species ◽  
Length Frequency ◽  
Wet Season ◽  
Important Predator ◽  
Commercially Important ◽  
Predatory Fishes ◽  
One Year ◽  
Length Frequency Analysis

Caranx bucculentus is the most abundant secondary consumer and the most important predator of commercially important penaeids in the Gulf of Carpentaria. More than 18 000 individuals of this species were collected from 406 trawls during 13 cruises in the Gulf of Carpentaria from 1986 to 1991. The species was most abundant in coastal waters, with a maximum biomass at a depth of 28.1 m. Catches were higher in prawn-trawling grounds than elsewhere in the gulf, and prawns comprised a greater proportion of the diet than is the case for other predatory fishes. Interannual variations in biomass occurred, but there were no differences between cruises or seasons. The decreased catches at night may have resulted from vertical die1 migration of C. bucculentus. Sexual maturity is reached at 110 mm standard length and about one year of age, which is much younger than in congeners. Back-calculated birth dates of C. bucculentus show year-round recruitment that peaks in the pre-wet season months of spring, and gonadosomatic index values are generally higher in the pre-wet season than in the wet season. Gonadosomatic index values remain relatively high (> 1.0), which indicates continuous spawning by C. bucculentus in the gulf. Other large tropical species of Caranx spawn annually, in summer. C. bucculentus fecundities range from 18 000 eggs for a 120-mm fish to about 650 000 eggs for a 460-mm fish. A possible switch is seen in the sex ratio-males seem to predominate at smaller sizes, whereas females seem to predominate among bigger fish. MULTIFAN length-frequency analysis gave values of L∞ = 538.8 mm (8 years old) and K= 0.305 year -1. A growth rate of 822 mm year-1 at L∞/2 is comparable to the growth rates of other tropical carangids. The diet of C. bucculentus throughout the gulf is dominated by epibenthic crustaceans and teleosts.

scholarly journals Comparison of beam trawl catch, by-catch and discard in fishing and non-fishing areas – a case study from the northern Adriatic Sea

2021 ◽  
Vol 22 (1) ◽  
pp. 108
Author(s):  
DARIA EZGETA -BALIĆ ◽  
NEDO VRGOČ ◽  
IGOR ISAJLOVIĆ ◽  
DAMIR MEDVEŠEK ◽  
ANTE VUJEVIĆ ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Beam Trawl ◽  
Northern Adriatic Sea ◽  
Important Species ◽  
Northern Adriatic ◽  
Trawl Fishery ◽  
Trawl Catch ◽  
Commercially Important ◽  
By Catch ◽  
Trawl Fisheries

Beam trawl fishery is highly important in the Croatian part of the northern Adriatic wherein 116 vessels have a licence for this type of fishing gear. A sharp decrease in the beam trawl catch observed since 2015 has raised concern about not only socio-economic issues but also ecological issues and the effect that beam trawl fisheries have had on exploited stocks. Besides the effect that beam trawl fisheries can have on targeted economically important species, intensive dredging can cause long-term changes in the benthic community. Therefore, this study aimed to detect the effect that this type of fishing gear has on target and by-catch species. Furthermore, survey data were compared with the official beam trawl fishery data gathered through Vessel Monitoring System data together with fishermen’s logbooks. Our research targeted two adjacent areas: an area where beam trawl fishing is allowed and an area where it is forbidden. The results demonstrate that the commercially important catch represented a minor share of the total beam trawl catch in both survey areas, while discard made up more than 93% of the total catch. The main beam trawl commercially important species in the Croatian part of the northern Adriatic Sea was Pecten jacobaeus, followed by Solea solea and Ostrea edulis. Our results suggest that beam trawl fisheries mostly affect target bivalve species and some non-commercial benthic species (e.g. sponges). The differences recorded between areas could suggest that beam trawl fisheries cause changes mostly in the P. jacobaeus population.

scholarly journals Sharks and batoids (Subclass Elasmobranchii) caught in the industrial fisheries off the Brazilian North coast

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Alexandre Pires Marceniuk
Keyword(s):  
New Records ◽  
Fish Fauna ◽  
North Coast ◽  
Pink Shrimp ◽  
Trawl Fishery ◽  
The North ◽  
Elasmobranch Species ◽  
Fish Collection ◽  
Commercially Important ◽  
By Catch

The Brazilian North coastline comprises a total area of approximately 223,000 km2, representing one of the world’s most essential fishing grounds. Availability of data on the diversity of fishes caught in the industrial fishery trawlers in the region are usually limited to the commercially important and targeted species. Knowledge gaps on the related marine fish fauna are eminent, which hamper both fisheries and conservation efforts of the local biodiversity. A comprehensive taxonomic list of elasmobranch species captured off the North coast from Brazil through industrial trawl fishery is provided. Trawling operations acting regionally included pink-shrimp and several fish (outrigger trawling) and piramutaba catfish (pair trawlers). Sixty-eigth elasmobranch species belonging to 20 families and nine orders were recorded for this region, according to fish collection, fishery observer and literature data. Thirty-two are by-catch species caught in the local trawl operations, including endemic and rare species as well as four new records and one possible undescribed species of electric ray.

Studies on reproductive biology and ecology of blue swimming crab Portunus pelagicus from Chilika Lagoon, Orissa, India

2010 ◽  
Vol 91 (1) ◽  
pp. 257-264 ◽  
Author(s):  
D. Sahoo ◽  
S. Panda ◽  
B.C. Guru
Keyword(s):  
Gonadosomatic Index ◽  
Carapace Width ◽  
Food Habit ◽  
Total Body Weight ◽  
Fish Bone ◽  
Chilika Lagoon ◽  
Portunus Pelagicus ◽  
Commercially Important ◽  
Total Body ◽  
The Relationship

Portunus pelagicus a commercially important crab species found in Chilika lagoon constitutes about 20% of the total crab production. The carapace width (CW) ranges from 4.5–10.5 cm in both the sexes during the study period. The maximum abundance of male was at 6.6 to 7.5 cm CW whereas the females predominate from 6.6 to 9.5 cm CW. The relationship between carapace length (CL) and CW is linear in both sexes which indicates isometric growth. However, the relationship between CL, CW with total body weight (TW) is exponential. The food habit from gut content analysis shows that the species is highly carnivorous and the main food items include prawn carapace and appendages (27.58%), molluscan remaining (21.55%), fish bone (7.75%), seagrass (1.72%), unidentified materials (4.31%) and the mixed food (37.06%). The feeding index was found highest (80.95%) in February whereas it is lowest (60.9%) in June. The mature females are observed from May to July with a peak in July in the lagoon. The highest gonadosomatic index is found in July with an average CW of 10.5 cm. No berried females are found in the study period, which indicates that it did not spawn inside the lagoon and migrates to the sea during the rainy season.

scholarly journals Actual conditions of discards of by-catch from small-scale trawl fishery in Ariake Sea

2003 ◽  
Vol 69 (3) ◽  
pp. 330-336 ◽  
Author(s):  
YOSHIO HIRAI ◽  
HIDEYUKI NISHINOKUBI
Keyword(s):  
Small Scale ◽  
Ariake Sea ◽  
Trawl Fishery ◽  
By Catch

scholarly journals Factors affecting rule compliance with mesh size regulations in the Baltic cod trawl fishery

2007 ◽  
Vol 64 (8) ◽  
pp. 1603-1606 ◽  
Author(s):  
Petri Suuronen ◽  
Vesa Tschernij ◽  
Pekka Jounela ◽  
Daniel Valentinsson ◽  
P-O. Larsson
Keyword(s):  
Gadus Morhua ◽  
Management Practice ◽  
Mesh Size ◽  
Factors Affecting ◽  
Trawl Fishery ◽  
Management Measures ◽  
Gradual Introduction ◽  
Minimum Landing Size ◽  
The Baltic ◽  
Baltic Cod

Abstract Suuronen, P., Tschernij, V., Jounela, P., Valentinsson, D., and Larsson, P-O. 2007. Factors affecting rule compiance with mesh size regulations in the Baltic cod trawl fishery. – ICES Journal of Marine Science, 64: 1603–1606. In this study, we evaluate the efficiency and applicability of a series of gear-based management measures, enforced since 1990, whose purpose was to improve size selectivity in the trawl fishery for Baltic cod (Gadus morhua). In general, our study revealed that these measures had no marked effect on the capture and discard of young cod. Legal and illegal manipulation of selective codends was widespread. The adoption of a codend design that offered a modest increase in selectivity, but had a good match with the legislated minimum landing size (MLS), led to greater compliance, demonstrating that a mismatch between MLS and selectivity should be avoided. It was also obvious that, generally, the fishing industry did not tolerate large short-term losses. Our evaluation is that overly ambitious rules will be circumvented, and frequent and incoherent changes in the regulations represent bad management practice. A gradual introduction of restrictions and participation by fishers in the decision-making process will increase compliance.

scholarly journals Pengaruh ekstrak minyak cumi pada umpan bubu terhadap hasil tangkapan kepiting bakau dan rajungan di Perairan Malise Kecamatan Tabukan Tengah

2016 ◽  
Vol 2 (3) ◽  
Author(s):  
Maichel Arvan Pananggung ◽  
Ivor L. Labaro ◽  
Emil Reppie
Keyword(s):  
Coastal Waters ◽  
Scylla Serrata ◽  
Fishing Gear ◽  
Swimming Crab ◽  
Portunus Pelagicus ◽  
Mangrove Crab ◽  
Gill Net ◽  
Oil Extract ◽  
Mangrove Crabs ◽  
By Catch

ABSTRACT Mangrove crab (Scylla serrata) and swimming crab (Portunus pelagicus) are economically important marine commodities produced from the coastal waters of Sangihe Islands Regency. But those marine commodity products are usually only caught accidentally with a bottom gill net. There has been a special trap fishing gear for that resources, but not known well by local fishermen. Addition of squid oil extraction baits could increase the fishing power of mangrove crab and swimming crab traps. This research aims to study the effect of squid oil extract on traps bait to catch mangrove crab and swimming crab; and identify the types of biota captured. This research was done in coastal waters of Malise village, Tabukan Tengah District of Sangihe Islands Regency for 2 weeks September 2015; based on experimental method. Six unit traps were operated ten trips where three units of them used scad mackerel bait that injected with squid oil extract, and tree other units just used scad mackerel bait without extract; and the capture data were analyzed using t test. The catch was 142 individuals (135 mangrove crabs and 7 swimming crab); where 86 crabs was caught by scad mackerel bait with squid oil extract, and 56 crabs caught with bait without squid oil extract. The analysis showed that the use of squid oil extracts on trap baits increased the catch. Keywords: mangrove crab, swimming crab,trap baits, squid oil extract, Sangihe   ABSTRAK[1] Kepiting bakau (Scylla serrata) dan rajungan (Portunus pelagicus) merupakan komoditi hasil laut ekonomis penting yang dihasilkan dari perairan pantai Kabupaten Kepulauan Sangihe. Tetapi komoditi hasil laut tersebut biasanya hanya tertangkap tanpa sengaja (by catch) dengan jaring insang dasar. Sebenarnya telah ada alat tangkap bubu khusus untuk kepiting bakau dan rajungan, tetapi belum dikenal oleh nelayan lokal. Pemberian ekstrak minyak cumi pada umpan, diduga dapat meningkatkan kemampuan tangkap dari bubu kepiting bakau dan rajungan. Penelitian ini bertujuan untuk mempelajari pengaruh ekstrak minyak cumi pada umpan bubu terhadap hasil tangkapan kepiting bakau dan rajungan, dan mengidentifikasi jenis-jenis biota yang tertangkap. Penelitian ini dilakukan di perairan Malise Kecamatan Tabukan Tengah, Kabupaten Kepulauan Sangihe; selama 2 minggu pada bulan September 2015; yang didasarkan pada metode eksperimental. Enam unit bubu dioperasikan selama sepuluh trip untuk mengumpulkan data; di mana tiga unit menggunakan umpan ikan layang yang disuntikan ekstrak minyak cumi, dan tiga unit lainnya hanya menggunakan umpan ikan laying tanpa ekstrak; dan data dianalisis dengan uji t. Tangkapan total berjumlah 142 ekor (135 ekor kepiting bakau dan 7 ekor rajungan); di mana 86 ekor tertangkap dengan umpan layang yang diberi ekstrak minyak cumi, dan 56 ekor tertangkap dengan umpan tanpa ekstrak. Hasil analisis menunjukkan bahwa penggunaan ekstrak minyak cumi pada umpan bubu, memberikan hasil tangkapan yang sangat berbeda dibandingkan dengan umpan tanpa ekstrak minyak cumi. Kata-kata kunci: kepiting bakau, rajungan, umpan bubu, ekstrak minyak cumi, Sangihe  

The by-catch of sharks in the western Mediterranean (Balearic Islands) trawl fishery

2003 ◽  
Vol 61 (1-3) ◽  
pp. 7-18 ◽  
Author(s):  
A Carbonell ◽  
F Alemany ◽  
P Merella ◽  
A Quetglas ◽  
E Román
Keyword(s):  
Western Mediterranean ◽  
Balearic Islands ◽  
Trawl Fishery ◽  
By Catch
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