Boat Seine Fishery Research Articles

Analysis of profitability deterioration factors of anchovy boat seine fishery in South Korea

Analysis of profitability deterioration factors of anchovy boat seine fishery in South Korea

Application of a multi-annual generalized depletion model to the Mediterranean sandeel fishery in Catalonia

A multi-annual generalized depletion (MAGD) model was applied to the data-limited Mediterranean sandeel boat seine fishery in Catalonia. The results show that catch and effort data at high temporal frequency (month), complemented with biological information on mean body weight and initial estimates of natural mortality and time of recruitment to the fishery, can be used to produce assessment results of interest to fisheries management. The estimates of fishing mortality obtained for the Mediterranean sandeel in this fishery are very low compared to natural mortality estimates (less than 10 %) and the important fluctuations in recruitment strength suggest that the dynamics of this fishery are mainly driven by density-dependent effects on the population dynamics of the species. Given the high rate of natural mortality estimated (∼ M = 2 y−1), its short life-span (1–2 y) and that exploitation is based on age 0 individuals, it is recommended to keep exploitation rates at current levels (<4%), which can be adapted on a short time basis, subject to the perceived availability of the stock. This low exploitation rate is compatible with a precautionary escapement biomass of 40 %. A parallel stock assessment was carried out with a surplus production model (SPiCT), which led to similar trends in biomass and fishing mortality as the MAGD model application. The parameter estimates obtained with both models have wide confidence intervals, particularly for the quantities related to population size, suggesting that these data-limited models are likely to suffer from low precision. Precision was lower for SPiCT than for MAGD, and the performance diagnostics for SPiCT were poor. The MAGD model can be used for small-scale fisheries that are unlikely to meet the requirements of standard stock assessments based on catch-at-age methods and can provide indicators (fishing mortality, vulnerable biomass) of interest to fisheries managers.

The Performance of the New Fishing Gears of the Anchovy Boat Seine Fishery Using a Hydroacoustic Method

The anchovy boat seine fishery is conducted only in South Korea and Japan. This fishery has the largest fishing gear among towing net fisheries in the world. Hence, the expenses of manufacturing and repairing the fishing gear become formidable, and handling the huge fishing gear involves significant labor force and risk. Our research team has developed a small and a large improved fishing gears of the anchovy boat seine fishery. The performance of two improved fishing gears compared to the existent fishing gear was investigated using a hydroacoustic method. In particular, net shapes of the two improved gears and existent one were examined. As a result, it had a tendency that the height of the net mouth increased as the distance between two net vessels broadened. Between the small and large improved fishing gears, the height of the net mouth was not much different. The morphological characteristics of fish schools among two improved fishing gears and the existent one were precisely described. In consideration with the net shape, noise, and the number of escaped anchovy schools, the large improved fishing gear had the best performance. In addition, the water temperature and salinity at 10 ~ 20 m where anchovy schools were mainly distributed was approximately 16 °C and 33.3 psu, respectively. These results can contribute the efficiency and safety of the anchovy boat seine fishing operation.

Balearic Islands boat seine fisheries: the transparent goby fishery an example of co-management

Abstract An economically important, small-scale fishery operates during the winter months in Mallorca. Using a special surrounding net that is hauled over the sand and gravel bottoms of bays at depths reaching 30 m, it primarily targets Aphia minuta and Pseudaphya ferreri, but other goby species and juveniles of the Pagellus spp are also caught. Similar fisheries are operated on the Spanish coast and in Italy. This fishery is run with specific licenses, equipment controls, and closed seasons (based on species availability). In cooperation with local fishermen, the administration has in recent years established a daily quota for sustaining the sales prices 22of the species caught. A management plan was set up in 2013 in accordance with European Union rules to ensure the sustainability of the fishery. Its sustainable quotas have been set at 30 kg/day/boat for A. minuta and 50 kg/day/boat for P. ferreri, and the by-catch cannot exceed 10% of the total catch. Landings are permitted in 11 fixed ports and only 35 boats can fish with the regulated nets from December 15 to April 30. A co-management committee was created with the participation of the public administration, fishermen’s associations, researchers, and certain non-governmental organizations. The co-management process was revised and fishermen’s opinions were obtained in a successful enquiry that was answered by the majority of the operating fleet, and their views on the management rules will be considered in future regulations. The co-management of the small-scale boat seine fishery in the Balearic Islands is thus an ongoing collaborative and communicative process in a local community that continues to evolve over time. Although the fishermen are represented by their port guilds, communication efforts are necessary in the near future to ensure the success of the co-management process.

Catch composition and discard of the boat seine in the İstanbul Strait (Turkey)

This study attempted to determine certain characteristics of the species caught in the boat seine fishery in the İstanbul Strait during the 2009-2010 fishing season, including catch composition, commercial and nontarget catch ratios, catch per unit effort (CPUE), and the length distributions of commercial species. A survey of 20 boat seine operations detected species belonging to the following 3 different taxonomic groups: 26 Osteichthyes, 2 Crustacea, and 1 Mollusca. Of all of the nontarget species, 13 were commercial, 14 were noncommercial, and only 1 was under threat. Of the total catch, the proportion of the commercial species in the nontarget catch was 31.3%, and that of the discarded catch, which the fishermen did not take into account, was 2.8%. According to the Spearman rank correlation test, there was a significant correlation between the total catch and the discarded catch (r = 0.759); the size of discarded catch increased as the catch increased (P = 0.000). It was clear from the data that overfishing was seen in the commercial species.

Assessment of the Relative Catch Performance of a Surrounding Net without the Purse Line as an Alternative to a Traditional Boat Seine in Small-Scale Fisheries

AbstractThe catch performance of a traditional Ligurian boat seine, which is not in line with the European Union regulation, was compared with an experimental surrounding net without the purse line as a potential legal alternative. The relative catch performance between the two gear types was assessed using a new catch comparison method requiring neither paired data collection nor equal number of hauls with the two gears. The comparison was based on the catches of the three species that comprise the bulk of the catch in traditional Ligurian boat seine fisheries: Bogue Boops boops, Saddle Bream Oblada melanura, and Blotched Picarel Spicara maena. The experimental gear exhibited poor catch efficiency for all three species, since it was estimated that the catches would only be 2, 64, and 6%, respectively, of those with the boat seine. For both Bogue and Blotched Picarel these reductions in catch performance were found to be highly significant proving that the experimental surrounding net is not a viable solu...

瀬戸内海東部のイカナゴ船曳網漁を対象とした漁業シミュレータの開発

In the eastern Seto Inland Sea, the boat seine fishery for Japanese Sand Lance is flourishing, and appropriate control of fishing operation is important from industrial, cultural and ecological points of view. In this study, surveys on actual condition of the fishery were conducted and a fishing operation simulator was developed, which consisted of a 3-D hydrodynamic model, a fish behavior model and a fishing operation model. Validation analysis showed that the simulator had good reproducibility of temperature and salinity fields, fishing ground distributions and time series of fish catches and sales. Moreover, the simulation results pointed to the particular importance of quantifying vertical migration properties of this species for improving of accuracy of the simulator.

Fishery Despoliation of Japan and History of Anchovy Boat Seine Fisheries

Fishery Despoliation of Japan and History of Anchovy Boat Seine Fisheries

Discards of the commercial boat seine fisheries on &lt;i&gt;Posidonia oceanica&lt;/i&gt; beds in the eastern Adriatic Sea

Scientific observer records were used to estimate the retained and discarded catch composition of the commercial boat seine fisheries over Posidonia oceanica (Linnaeus) Delile meadows in the eastern Adriatic, from November 2008 to December 2009. A total of 91 fish and cephalopod species were recorded in the catches, of which 20 species were always retained, 40 were always discarded and the remaining 31 were selected depending on size (only larger specimens were retained). The most abundant species in the retained catch were Spicara smaris , Atherina hepsetus and Mullus barbatus , while Chromis chromis, Symphodus ocellatus and small specimens of Boops boops dominated the discards. An estimated 43.5% by number and 28.5% by weight of the total catch were discarded. Since the minimum landing size (MLS) is regulated for only 4 out of the 15 most important species in this study, and even these regulations are only partially followed, discarding practices were generally market-driven. The retained and discarded amounts of the catch as well as the numbers of retained and discarded species showed a seasonal pattern. The catches recorded during summer/autumn were generally larger than those in winter/spring. High rates of immature specimens were observed for the most important species, which is probably related to the role of Posidonia beds as important nursery grounds.

Boat seines in Greece: Landings profiles and identification of potential métiers

SuMMarY: although boat seines have a significant share in the total fish landings in Greece, there is little information on boat seine fisheries. the present study aims to identify boat seine metiers on a national level and contribute to a better understanding of their operation in Greece. We used boat seine landings data collected from a large number of ports in the aegean and east ionian Sea between 2002 and 2006. the landings profiles were grouped with a two-step procedure: the first step involved a factorial analysis of the log-transformed landings profiles, and the second step was a classification of the factorial coordinates (hierarchical agglomerative clustering). Six metiers were identified in the aegean Sea, and three in the ionian Sea. the ‘picarel-bogue’ metier was the most important in both seas, accounting for 54% and 88% of the fishing trips of the sample in the aegean and ionian Seas respectively. apart from picarel and bogue, other important target species were red mullet, european squid, common pandora, chub mackerel, and european pilchard. varying spatial (within the aegean and ionian Seas) and seasonal patterns were evident for the identified metiers.

Fishery Management and Mutual Agreement Procedures of Seto Inland Sea Boat Seine Fisheries in Tokushima Prefecture

Fishery Management and Mutual Agreement Procedures of Seto Inland Sea Boat Seine Fisheries in Tokushima Prefecture

Length frequency distribution of &lt;i&gt;Ethmalosa fimbriata&lt;/i&gt; (Bowdich) in cross River Estuary and Adjacent Coastal waters

Studies on the length distribution of bonga, Ethmalosa fimbriata, in the Cross River estuary and adjacent coastal waters were conducted from October 1999 to December 2000. A total of 15,182 specimens of bonga from gill nets, purse seine and boat seine fisheries were measured. Post-larvae measuring between 2 cm and 9 cm were found in the lower estuary with a modal length of 4 cm. Juveniles from gill net fishery ranged in length from 8 cm to 20 cm with a modal length of 13cm. Adults and sub-adults ranging in size from 16 cm to 33 cm were caught from the coastal waters alongside the juveniles, by the purse seine fishery. Two modal lengths of 17 cm and 25 cm were observed in the coastal waters. Three modal length classes were observed in the catches from the Cross River estuary and adjacent coastal waters: these are 4 cm, 13 cm and 25 cm. It is concluded that the Cross River estuary is a nursery ground for bonga, Ethmalosa fimbriata. Key Words: Ethmalosa fimbriata, length distribution, Cross River estuary, coastal waters, nursery. (Global Journal of Pure and Applied Sciences: 2002 8(3): 299-304)

Reproduction and growth of Jack-knife shrimp, Haliporoides sibogae, off south-western Kyushu, Japan

Jack-knife shrimp Haliporoides sibogae (Decapoda, Penaeoidea, Solenoceridae) is the target species in a boat seine fishery in the East China Sea off south-western Kyushu, Japan. The reproduction and growth of this species were studied based on a large number of specimens which were sampled during 19 months in a commercial fishing ground. The body length at sexual maturity for females was estimated to be 100 mm (2 year old). The spawning season continues from September to April and peaks during late January and late March. Only the 3 year old group of females matured in the early spawning season, while the 2 and 3 year old groups matured in the primary spawning season. The growth patterns for both sexes were well modelled by fitting the Pauly and Gaschüktz equations to the mean body lengths at various ages. The growth rates were highest between summer and autumn and lowest during the primary spawning season. Females grow faster and attain a greater size earlier than males of the same age group. The H. sibogae population off south-western Kyushu has lower values of asymptotic size and higher values of growth coefficient in comparison to other local populations of this species, such as those in Kii Channel and eastern Australia.

長崎県北部沿岸域におけるトビウオ未成魚の漁獲量変動要因

The catch of young flying fish, Cypselurus hiraii and Cypselurus heterurus doederleini, by boat seine fishery in the northrn coastal waters of Nagasaki Prefecture, Japan shows wide yearly fluctuations. The effects of five factors on the fluctuations were recognized by multiple regression analysis using data from 1976 to 1987. The factors are as follows: annual catch of adult flying fish by 9 set-nets in the coastal region of Yamaguchi Prefecture (X1); average surface water temperature in July (X2) and catch by FADs of dolphin fish as predators in August (X5) in the offshore region of Yamaguchi Prefecture; days of north-east wind at Hirado Meteorological Station, Nagasaki Prefecture (X6); and number of boat seine belonging to Ikitsuki Fisheries Cooperative Association, Nagasaki Prefecture (X7). The relationship of the annual catch of young flying fish at Ikitsuki Fisheries Cooperative Association (Y) to these factors is as follows: Y=-2221.9+0.210X1+96.287X2-1.765X5+4.040X6+8.139X7The regression is significant at the 1% level. The estimated annual catch closely follows the trend of the actual catch. The actual values of the catch in 1988 and 1989 are within the confidence margins at the 95% level. Thus, the equation can be used to predict the catch for the next fishing season.