Taking the Initiative on Maltese Trawl Industry Management. Industry and Science Collaboration on Identifying Nursery and Spawning Areas for Trawl Fisheries Target Species

2020 ◽  
pp. 249-262
Author(s):  
Nicholas Flores Martin
Keyword(s):  
Target Species ◽  
Spawning Areas ◽  
Science Collaboration ◽  
Trawl Fisheries

scholarly journals Spanish otter trawl fisheries in the Cantabrian Sea

2010 ◽  
Vol 67 (8) ◽  
pp. 1604-1616 ◽  
Author(s):  
Antonio Punzón ◽  
Carmen Hernández ◽  
Esther Abad ◽  
José Castro ◽  
Nelida Pérez ◽  
...  
Keyword(s):  
Hierarchical Classification ◽  
Horse Mackerel ◽  
Otter Trawl ◽  
Target Species ◽  
The West ◽  
Market Conditions ◽  
Blue Whiting ◽  
Classification Technique ◽  
Main Target ◽  
Trawl Fisheries

Abstract Punzón, A., Hernández, C., Abad, E., Castro, J., Pérez, N., and Trujillo, V. 2010. Spanish otter trawl fisheries in the Cantabrian Sea. – ICES Journal of Marine Science 67: 1604–1616 A non-hierarchical classification technique (clustering large applications, CLARA) was used to identify four fishing tactics of Spanish otter trawlers in the Cantabrian Sea (ICES Division VIIIc) from 1983 to 2004: mixed fishing, blue whiting fishing, horse mackerel fishing, and mackerel fishing. There were no significant differences in the fishing tactics employed by two trawl fleets identified using a non-hierarchical classification technique (partition around medoids). There was, however, a decline in the use of the blue whiting fishing tactic from 2000 on, perhaps as a result of competition with pairtrawls, a gear whose main target species is blue whiting. There was an increase in the number of trips using the mackerel fishing tactic from 1996, a change possibly caused by improved market conditions. Between 2000 and 2004, the fleets had two distinct behaviour patterns, identified depending on the area in which they operated. The study area could therefore be subdivided into two areas based on the prevalence of the fishing tactic followed. The horse mackerel fishing tactic was more commonly used in the west, and the mixed fishing tactic in the east.

Can we define target species in Mediterranean trawl fisheries?

2003 ◽  
Vol 59 (3) ◽  
pp. 431-435 ◽  
Author(s):  
Konstantinos I Stergiou ◽  
Athanassios Machias ◽  
Stylianos Somarakis ◽  
Argyris Kapantagakis
Keyword(s):  
Target Species ◽  
Trawl Fisheries

scholarly journals Commercial catches and discards composition in the central Tyrrhenian Sea: a multispecies quantitative and qualitative analysis from shallow and deep bottom trawling

2021 ◽  
Vol 22 (3) ◽  
pp. 521
Author(s):  
FRANCESCO TIRALONGO ◽  
EMANUELE MANCINI ◽  
DANIELE VENTURA ◽  
STEPHANIE DE MALERBE ◽  
FRANCESCO PALADINI DE MENDOZA ◽  
...  
Keyword(s):  
Benthic Communities ◽  
Human Consumption ◽  
Tyrrhenian Sea ◽  
Target Species ◽  
Catch Per Unit Effort ◽  
Management Measures ◽  
Starting Point ◽  
The Mean ◽  
Negative Impacts ◽  
Trawl Fisheries

In the Mediterranean Sea, the catch of bottom trawl fisheries is composed of a complex mix of fish and invertebrates with a considerable amount of discards. Seasonal composition of catches and discards of bottom trawls operating at different depths in the central Tyrrhenian Sea were investigated from October 2014 to October 2015. The mean total catch per unit effort (CPUE) ranged between 30.93±8.43 and 27.52±9.88 kg/h in shallow and deep fishing grounds, respectively. The discarded fraction of the catch was 39.9 % in shallow and 43.3% in deep fishing grounds. The mean CPUE of commercial target species were similar in shallow and deep trawling (10.81+5.82 vs 8.92±3.16 kg/h). The commercial bycatch was lower in shallow (6.66±1.25 kg/h) than in deep grounds (8.24±2.91 kg/h), whilst the discards were lower in deep (10.43±5.14 kg/h) than shallow grounds (13.43±5.29 kg/h). Overall, 246 species were caught during fishing operations, out of which 209 were included in discards. The number of species recorded in shallow grounds (199 caught species with 166 discarded) was higher than that recorded in deep grounds (116 caught species with 102 discarded). Fish were the most represented taxa in the shallow discards, followed by echinoderms; crustaceans, and were the main discarded taxa in deep water. Depth was the main factor affecting both commercial catches and discards composition, whereas the season affected the CPUE of main target species only. The results confirmed that discards were higher in shallow than in deep trawling, suggesting that the latter is more efficient than the former in catching fishery resources for human consumption. Understanding the factors that affect discarding is the starting point for adopting management measures to mitigate negative impacts of trawl fisheries on marine resources and benthic communities.

Reproductive biology and estimates of length and age at maturity of longtail tuna (Thunnus tonggol) in Australian waters based on histological assessment

2019 ◽  
Vol 70 (10) ◽  
pp. 1419 ◽  
Author(s):  
Shane P. Griffiths ◽  
Mitchell T. Zischke ◽  
Tonya van der Velde ◽  
Gary C. Fry
Keyword(s):  
Stock Assessment ◽  
Interval Length ◽  
Target Species ◽  
Age At Maturity ◽  
The Past ◽  
Future Assessment ◽  
Spawning Areas ◽  
Stock Assessments ◽  
The Indian Ocean ◽  
Longtail Tuna

The annual global catch of longtail tuna (Thunnus tonggol) has almost tripled in the past 20 years. In the Indian Ocean tuna fishery, longtail tuna catches now exceed those of some principle target species (e.g. bigeye and albacore tuna), resulting in numerous stock assessments concluding the species has been subject to overfishing and overfished for several years. Stock assessment is currently hindered by unreliable biological and catch data, which provided the impetus to study and describe the reproductive dynamics of longtail tuna in Australian waters using histology. Mean (95% confidence interval) length and age at 50% maturity were 535mm (463–570mm) and 2.51 years (2.14–2.79 years). Spawning occurred between October and February, when females produced a mean (±s.d.) of 1516680±743980 oocytes per spawning. Three spawning locations were confirmed based on the presence of postovulatory follicles in a small number of ovaries, although major spawning areas may be located offshore. The present study provides reliable maturity and fecundity ogives that may improve future assessment of longtail tuna stocks throughout the Indo-Pacific region.

scholarly journals Anglerfish discard estimates and patterns in Spanish Northeast Atlantic trawl fisheries

2008 ◽  
Vol 65 (7) ◽  
pp. 1350-1361 ◽  
Author(s):  
Paz Díaz ◽  
Juan Santos ◽  
Francisco Velasco ◽  
Alberto Serrano ◽  
Nélida Pérez
Keyword(s):  
Atlantic Ocean ◽  
Length Distribution ◽  
Bottom Trawl ◽  
Trawl Survey ◽  
Marine Science ◽  
Target Species ◽  
Northeast Atlantic ◽  
Northeast Atlantic Ocean ◽  
Trawl Fisheries ◽  
Trawl Surveys

Abstract Díaz, P., Santos, J., Velasco, F., Serrano, A., and Pérez, N. 2008. Anglerfish discard estimates and patterns in Spanish Northeast Atlantic trawl fisheries. – ICES Journal of Marine Science, 65: 1350–1361. Estimates of Spanish bottom trawl discards of anglerfish Lophius budegassa and Lophiuspiscatorius in the Northeast Atlantic Ocean are presented. Both species are commercially valuable in ICES Subareas VI and VII, and Divisions VIIIc and IXa. Information was obtained from observers on board during discard-monitoring programmes. Raising by effort, rather than by landings and target species, was used to determine the total annual discards by weight and number, the discard percentage, and the discard length distribution by stock throughout the dataseries. By weight and number, discards varied interannually, ranging from 4 to 600 t (∼28 000–7 000 000 fish) in northern stocks of anglerfish, and from 1 to 100 t (∼20 000–400 000 fish) in southern stocks. The discard percentage for both species and northern and southern stocks therefore ranged between 2 and 76% by number. Length distributions of the discarded anglerfish show that most were juveniles, although the pattern differed in years with high or with low rates of discarding. The number of juveniles caught apparently increased in most areas after 2000. Correlations between the quantities discarded and recruitment indices from French and Irish trawl surveys were found for northern stocks and with Spanish trawl survey indices for southern stocks.

scholarly journals FLEXSELECT: counter-herding device to reduce bycatch in crustacean trawl fisheries

2018 ◽  
Vol 75 (6) ◽  
pp. 850-860 ◽  
Author(s):  
Valentina Melli ◽  
Junita D. Karlsen ◽  
Jordan P. Feekings ◽  
Bent Herrmann ◽  
Ludvig A. Krag
Keyword(s):  
Gadus Morhua ◽  
Melanogrammus Aeglefinus ◽  
Target Species ◽  
Merluccius Merluccius ◽  
Flexible Tool ◽  
Flatfish Species ◽  
Trawl Fishery ◽  
Merlangius Merlangus ◽  
Trawl Fisheries ◽  
Haddock Melanogrammus Aeglefinus

FLEXSELECT is a simple counter-herding device that aims at reducing the bycatch of fish by scaring them away from the trawl path without affecting the catches of the target species. FLEXSELECT was tested in the Norway lobster (Nephrops norvegicus) directed trawl fishery, as this includes bycatch of both roundfish and flatfish. Length-based data were collected for Nephrops, four roundfish species (cod (Gadus morhua), haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and hake (Merluccius merluccius)), and two flatfish species (plaice (Pleuronectes platessa) and lemon sole (Microstomus kitt)), and length-based catch comparisons were performed. No significant effect on the target species, Nephrops, was detected, whereas a reduction of 39% (CI: 29%–46%) was obtained for the overall number of fish. Catches of all the six fish species examined were significantly reduced by FLEXSELECT, with the efficiency varying considerably among species and over length classes. No significant diel differences were found for either roundfish or flatfish species. FLEXSELECT prevents bycatch species from interacting with the trawl, thus most likely enhancing their survival and fitness. Moreover, its fast attachment system makes FLEXSELECT a flexible tool, adaptable to different fisheries and catch goals.

scholarly journals Round scallops and square meshes: a comparison of four codend types on the catch rates of target species and by-catch in the Queensland (Australia) saucer scallop (Amusium balloti) trawl fishery

2008 ◽  
Vol 59 (10) ◽  
pp. 849 ◽  
Author(s):  
Anthony J. Courtney ◽  
Matthew J. Campbell ◽  
Darren P. Roy ◽  
Mark L. Tonks ◽  
Keith E. Chilcott ◽  
...  
Keyword(s):  
Sea Urchins ◽  
Catch Rate ◽  
Target Species ◽  
Bivalve Molluscs ◽  
Sea Stars ◽  
Incidental Capture ◽  
Trawl Fishery ◽  
By Catch ◽  
Catch Rates ◽  
Trawl Fisheries

Concern over the amount of by-catch from benthic trawl fisheries and research into the problem have increased in recent years. The present paper demonstrated that by-catch rates in the Queensland (Australia) saucer scallop (Amusium balloti) trawl fishery can be reduced by 77% (by weight) using nets fitted with a turtle excluder device (TED) and a square-mesh codend, compared with a standard diamond-mesh codend with no TED. This large reduction was achieved with no significant effect on the legal size scallop catch rate and 39% fewer undersize scallops were caught. In total, 382 taxa were recorded in the by-catch, which was dominated by sponges, portunid crabs, small demersal and benthic fish (e.g. leatherjackets, stingerfish, bearded ghouls, nemipterids, longspine emperors, lizard fish, triggerfish, flounders and rabbitfish), elasmobranchs (e.g. mainly rays) and invertebrates (e.g. sea stars, sea urchins, sea cucumbers and bivalve molluscs). Extremely high reductions in catch rate (i.e. ≥85%) were demonstrated for several by-catch species owing to the square-mesh codend. Square-mesh codends show potential as a means of greatly reducing by-catch and lowering the incidental capture and mortality of undersize scallops and Moreton Bay bugs (Thenus australiensis) in this fishery.

scholarly journals Finding the accelerator and brake in an individual quota fishery: linking ecology, economics, and fleet dynamics of US West Coast trawl fisheries

2013 ◽  
Vol 71 (2) ◽  
pp. 308-319 ◽  
Author(s):  
Isaac C. Kaplan ◽  
Daniel S. Holland ◽  
Elizabeth A. Fulton
Keyword(s):  
West Coast ◽  
Fishery Management ◽  
Fishing Effort ◽  
Target Species ◽  
The Pacific ◽  
The Us ◽  
Fleet Dynamics ◽  
Us West ◽  
Trawl Fisheries ◽  
Management Council

Abstract Isaac C. Kaplan, Daniel S. Holland, and Elizabeth A. Fulton. 2014. Finding the accelerator and brake in an individual quota fishery: linking ecology, economics, and fleet dynamics of US West Coast trawl fisheries. – ICES Journal of Marine Science, 71: 308–319. In 2011, the Pacific Fisheries Management Council implemented an individual transferrable quota (ITQ) system for the US West Coast groundfish trawl fleet. Under the ITQ system, each vessel now receives transferrable annual allocations of quota for 29 groundfish species, including target and bycatch species. Here we develop an ecosystem and fleet dynamics model to identify which components of an ITQ system are likely to drive responses in effort, target species catch, bycatch, and overall profitability. In the absence of penalties for discarding over-quota fish, ITQs lead to large increases in fishing effort and bycatch. The penalties fishermen expect for exceeding quota have the largest effect on fleet behaviour, capping effort and total bycatch. Quota prices for target or bycatch species have lesser impacts on fishing dynamics, even up to bycatch quota prices of $50 kg−1. Ports that overlap less with bycatch species can increase effort under individual quotas, while other ports decrease effort. Relative to a prior management system, ITQs with penalties for exceeding quotas lead to increased target species landings and lower bycatch, but with strong variation among species. The model illustrates how alternative fishery management policies affect profitability, sustainability and the ecosystem.

scholarly journals Assessment of the relative catch performance of hake, red mullet and striped red mullet in a modified trawl extension with T90 netting

2018 ◽  
Vol 82 (S1) ◽  
pp. 19 ◽  
Author(s):  
Iván Sola ◽  
Francesc Maynou
Keyword(s):  
Target Species ◽  
Commercial Catch ◽  
Red Mullet ◽  
Comparison Approach ◽  
Commercial Species ◽  
Nw Mediterranean ◽  
Catch Rates ◽  
Trawl Fisheries ◽  
Discernible Difference ◽  
European Hake

We studied the relative catch performance of a modified trawl fitted with an extension piece using a 90º turned mesh (T90) in comparison with a standard trawl net used in NW Mediterranean bottom trawl fisheries employing a diamond mesh net. The comparison was made by means of paired experimental hauls using the same fishing vessel with alternate deployments of the standard net (control) and the experimental net. We used the catch comparison approach for three target species of the fishery: European hake, red mullet and striped red mullet. Our results show that the experimental net significantly reduces the catches of small-size hake and red mullet (though there was no discernible difference for striped red mullet), reducing unwanted catches of regulated species under the Landings Obligation. The overall catch rates of hake, pooled over all sizes, also increased by an estimated 50%, while the catch rates of red mullet and striped red mullet were significantly lower. However, considering all commercial species, the experimental net produced losses of commercial catch and income estimated at 17% and 18%, respectively, which may pose a barrier to the adoption of this relatively simple, inexpensive solution.

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