Effects of time of the day on catch composition in monofilament and multifilament gillnets fishing

Author(s):  
Ilker AYDIN
Keyword(s):  
2017 ◽  
Vol 98 (8) ◽  
pp. 2099-2111
Author(s):  
Fikret Öndes ◽  
Michel J. Kaiser ◽  
Lee G. Murray

Baited trap or pot fisheries are considered to have relatively few wider ecosystem effects on the marine environment, particularly when compared with towed mobile fishing gear. However, this assumption is rarely tested in the field. This study aimed to determine the composition of non-target species that occur in crustacean pots and to assess spatial and temporal differences in catches in the waters around the Isle of Man, Irish Sea. The data were collected using fishery independent surveys and a questionnaire study. Based on fishery independent surveys, a total of five taxonomic groups and 43 species occurred as by-catch. The dominant by-catch species was velvet crab Necora puber. The by-catch per unit effort (BPUE) for all of the non-target species was low particularly in comparison to towed bottom gear fisheries around the Isle of Man. BPUE of species composition varied considerably between different locations around the Isle of Man. The results of both the fishery independent and questionnaire data suggested that the by-catch rates varied with season with peak BPUE occurring in spring which then declined into autumn and winter. By-catch composition did not decrease significantly with an increasing target species catch. Overall, by-catch was low relative to target species catch which may be partially attributable to the use of escape panels in pot fisheries in the Isle of Man.


2009 ◽  
Vol 66 (4) ◽  
pp. 699-707 ◽  
Author(s):  
Delphine Rocklin ◽  
Marie-Catherine Santoni ◽  
Jean-Michel Culioli ◽  
Jean-Antoine Tomasini ◽  
Dominique Pelletier ◽  
...  

AbstractRocklin, D., Santoni, M-C., Culioli, J-M., Tomasini, J-A., Pelletier, D., and Mouillot, D. 2009. Changes in the catch composition of artisanal fisheries attributable to dolphin depredation in a Mediterranean marine reserve. – ICES Journal of Marine Science, 66: 699–707. There is increasing evidence from previous studies, and from fishers’ observations, that coastal dolphins use fishing nets as an easily accessible feeding source, damaging or depredating fish caught in the nets. This study investigates the impact of dolphin depredation on artisanal trammelnets by analysing the catch composition of 614 artisanal fishing operations in the Bonifacio Strait Natural Reserve (France). Common bottlenose dolphins (Tursiops truncatus) attacked, on average, 12.4% of the nets and damaged 8.3% of the catch. However, attacked nets were characterized by statistically significantly higher catch per unit effort than unattacked ones. Catch composition also differed significantly after dolphin attacks; bentho-pelagic fish were more represented and reef-associated fish less represented. Our results suggest that (i) dolphins are attracted by high fish densities in the fishing area and/or nets, and (ii) their attacks induce specific fish-avoidance behaviour, according to the fish position in the water column. Although dolphins depredate a small part of the catch, damage to nets, not yet assessed in this area, could weaken the benefits that reserves can provide to artisanal fisheries.


2009 ◽  
Vol 57 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Marcelo Francisco de Nóbrega ◽  
Rosangela Paula Lessa

Age and growth of the king mackerel (Scomberomorus cavalla) were estimated for northeastern Brazil. A total of 405 sagittal otoliths from 140 males (24.4-112 cm), 73 females (28-114.8 cm) and 193 specimens of unknown sex (11.5-121 cm) were examined. Marginal increment analysis indicated an annual pattern for growth band deposition. The age classes ranged from 1 to 15 years. Length ranged from 11.5 to 121 cm. The Schnute model indicated that the von Bertalanffy growth model demonstrated the best adjustment, with p=1/b, and was therefore used for estimating growth. Back-calculated curves had smaller variances, giving the following estimated growth parameters for males: L∞= 116.8 cm, K = 0.190, t0 = 0.377; and females: L∞= 132.7 cm, K = 0.159 and t0 = 0.387. In order to compare the curves for males and females, the overlapping of 95% confidence intervals was performed for the parameters generated from the von Bertalanffy non-linear least square method. Specimens between 3 and 8 years of age represented 82.2% (n=5,783) of the catch composition, characterizing the species as a catchable stock in the region.


2018 ◽  
Vol 31 ◽  
pp. 6 ◽  
Author(s):  
Emmanuel K. Mbaru ◽  
Dorcas Sigana ◽  
Renison K. Ruwa ◽  
Elizabeth M. Mueni ◽  
Collins K. Ndoro ◽  
...  

Fish aggregating devices (FADs) have been widely used by commercial fisheries to increase the catchability of pelagic stocks in the open sea. FADs have the potential to enhance nearshore small-scale fisheries where stocks are often overfished. This study examined changes in catch composition, abundance, catch and effort, and aspects of diversity in Kenya's nearshore coastal fisheries after deployment of anchored fish aggregating devices (AFADs). The study combined both fishery independent and dependent methods in assessing changes in fish assemblages post-deployment. Results showed orders of magnitude increase in length, weight, commercial value, and catch per unit effort (CPUE) of landed catch after deployment of FADs suggesting that FADs had a positive effect on the local fishery. Species richness at FAD sites increased post-deployment (n = 281) compared to pre-deployment values (n = 223). Simultaneous use of several complementary structural indices may be required in order to accurately describe and monitor fish assemblages around the FADs. The findings suggest that AFADs are capable of creating both short and long-term impacts on livelihoods, with the potential to deflect pressure on the overfished nearshore fish stocks. However, more research will be needed on redistribution of fish around FADs, design and placement configuration, and site selection amongst others.


2018 ◽  
Vol 23 (2) ◽  
pp. 79
Author(s):  
Asep Priatna ◽  
Suprapto Suprapto

Any fish on swept area of bottom trawl could not be caught due to some technical factors during towing. However, it could be estimated by integrated of bottom trawl and acoustic survey. This paper describes the determination of some factors that affect the performance of trawl net during the bottom trawl survey in the waters of Tarakan. Surveys were carried out in May, August, and November 2012. A total of 57 stations of simultaneously acoustic-trawl were completed. Data collected from each station include catch composition, and variables of trawling operation (i.e. bottom depth, warp length, trawl door opening, towing speed, towing duration, and acoustic fish density). Principal component analysis was applied to identify variables might impact of trawling performance (i.e. fish density at the waters area, towing speed, towing duration, warp length, horizontal opening of trawl door, density of non-demersal at cod end, and bottom depth). Both towing speed and towing duration were not major component for trawl operation. According to test of significance for four variables (i.e. bottom depth, warp length, horizontal opening, biota non-demersal at cod end) which affected to fish density at waters area, that both of variable (i.e. warp length and bottom depth) were significant as the principal components for the performance of bottom trawl. 


2017 ◽  
Vol 14 (3) ◽  
pp. 313 ◽  
Author(s):  
Budi Nugraha ◽  
Enjah Rahmat

Tulisan ini menyajikan tentang status perikanan huhate di Bitung meliputi deskripsi unit penangkapan, daerah penangkapan, komposisi hasil tangkapan, catch per unit of effort, dan ukuran ikan pertama kali tertangkap. Data dikumpulkan selama tahun 2004 sampai dengan 2005. Hasil penelitian menunjukkan bahwa huhate yang terdapat di Bitung dioperasikan dengan kapal penangkapan yang terbuat dari kayu berukuran 50 sampai dengan 80 GT. Daerah penangkapan di sekitar lokasi rumpon di Laut Sulawesi dan Laut Maluku. Hasil tangkapan yang diperoleh terdiri atas cakalang (Katsuwonus pelamis), madidihang (Thunnus albacares), baby tuna (Thunnus spp.), dan tongkol (Auxis spp.) serta hasil tangkapan sampingan yaitu lemadang (Coryphaena hippurus) dan sunglir (Elagatis bipinnulatus). Hasil analisis catch per unit of effort diperoleh bahwa nilai catch per unit of effort baby tuna (Thunnus spp.) mengalami kenaikan pada bulan Agustus 2004, dan cakalang (Katsuwonus pelamis) mengalami kenaikan pada bulan September 2004. Hasil analisis terhadap ukuran pertama kali cakalang (Katsuwonus pelamis) tertangkap oleh huhate 49,3 FLcm. Ukuran ini lebih panjang dibandingkan ukuran pertama kali cakalang (Katsuwonus pelamis) matang gonad. Sedangkan hasil analisis terhadap ukuran pertama kali madidihang (Thunnus albacares) tertangkap oleh huhate 51,6 FLcm. Ukuran ini lebih pendek dibandingkan ukuran pertama kali madidihang (Thunnus albacares) matang gonad. This paper presents the status of pole and line fishery in Bitung of North Sulawesi, consisting of description of fishing gear, fishing ground, catch composition, catch per unit of effort, and length at first capture. Data were collected during the period of 2004 until 2005. Results show that the pole and line in Bitung operated by wooden vessels of 50 until 80 GT. The fishing grounds were the waters around FADs location in Sulawesi Sea and Maluku Sea. Catch composition consists of skipjack tuna (Katsuwonus pelamis), yellow fin tuna (Thunnus albacares), baby tuna (Thunnus spp.), and frigate tuna (Auxis spp.), while the bycatch consisted of dolphinfish (Coryphaena hippurus) and rainbow runner (Elagatis bipinnulatus). Catch per unit of effort analysis shows that catch per unit of effort value of baby tuna (Thunnus spp.) increased on August 2004, whereas catch per unit of effort value of skipjack tuna (Katsuwonus pelamis) increased on September 2004. The length at first capture of skipjack tuna (Katsuwonus pelamis) was 49,3 FLcm. The catch size was bigger than the length at first maturity for skipjack tuna (Katsuwonus pelamis). The length at first capture of yellowfin tuna (Thunnus albacares) was 51,6 FLcm. This catch size was smaller than the length at first maturity for yellowfin tuna (Thunnus albacares).


2020 ◽  
Vol 33 (2) ◽  
pp. 183-203
Author(s):  
Katia Meirelles Felizola Freire ◽  
Felipe Pinto Nascimento ◽  
Gecely Rodrigues Alves Rocha

This study describes shore-based competitive fishing events in Ilhéus, southern Bahia (Brazil), including catch composition, and provides information on the profile of recreational fishers participating in these events. Information was collected in all events promoted by the Clube de Pesca de Ilhéus (CLUPESIL) in 2007-2008. A total of 26 competitive fishing events were organized during this period, with 47 species caught. The top species were: Cathorops spixii, Menticirrhus littoralis, Trachinotus goodei, Eucinostomus melanopterus, Polydactylus virginicus, Atherinella brasiliensis, and Eucinostomus argenteus. These seven species represented 87% of the total catch in number and 78% in weight. Menticirrhus littoralis and Polydactylus virginicus are species of commercial interest and their catch was dominated by juveniles. Local recreational fishers were predominately middle-aged men, who tended to use small hooks and mainly shrimp as bait. They were consumption-oriented, but also released small fishes. During competitions, fishers used even smaller hooks. Most of them perceived shrimp trawling as the main factor affecting recreational fisheries. The use of larger hooks and a minimum size of 20 cm are suggested to decrease the capture of juveniles, mainly those of commercial importance. This study sets a baseline from which new studies can be proposed to access the current status of local recreational fisheries.


2010 ◽  
Vol 11 (2) ◽  
pp. 315 ◽  
Author(s):  
V. UNAL ◽  
D. ACARLI ◽  
A. GORDOA

The economic and harvest impacts of Marine Recreational Fishing (MRF) in Çanakkale Strait were analysed along with fishing policy, sociology and habits of fishers. Data sources included field survey data carried out along the entire length of the Çanakkale strait and policy information gathered from published sources. MRF policy is commendable, even in the fishing tourism sector, and is better developed than that in many other European countries. In Çanakkale, 9.9% of the population is recreational fishers. Recreational fishers are typically men (90%), primarily those between the ages of 25 and 49 yrs. The occupation of the recreational fishers ranged from self-employed (28%), students (28%), retired persons (22%) and public employees (15%), to currently-unemployed persons (7%). An analysis of diel behaviour showed that most recreational fishers preferred fishing during the day (56.1%), while the evening was the next most preferred time for fishing (18%), followed by the night-time (9.8%), while a substantial number of recreational fishers (16.1%) reported that they fished at any time of day. The most popular type of fishing was shore-based (68%), followed by boat-based (21%), and underwater fishing (11%). The mean daily fishing times were 6.07 h d-1, 6.18 h d-1 4.75 d-1 for boat-based, underwater and shore-based fishing, respectively. Summer and autumn were the preferred seasons for shore-based and underwater fishing, while autumn and winter were preferred for boat-based fishing. The highest Catch per Unit Effort (CPUE) was observed for boat-based fishing (2.77 kg h-1), followed by underwater (0.97 kg h-1) and shore-based fishing (0.81 kg h-1). The catch composition included 51 species, though the catch composition of each fishing type was mostly comprised of only 3 or 4 species. The impact of the MRF harvest was high (30% of commercial fishing), particularly for bluefish (Pomatomus saltatrix) and picarel (Spicara smaris) species. The economic impact of MRF was highly negative. Several indicators including the following revealed a high percentage of trading catch (47%) being conducted under the guise of a recreational label: annual fishing intensity, total costs, target species, and sales. At present, it is evident that the highly developed recreational fishing policy in Turkey is not sufficient to ensure that recreational fishing is sustainable or to prevent fishing conflicts in Turkey. This study revealed the need for establishing monitoring, control and surveillance programs to ensure the sustainability of fish resources and fisheries including MRF.


2017 ◽  
Vol 15 (1) ◽  
pp. 69
Author(s):  
Tri Ernawati ◽  
Bambang Sumiono

Penelitian mengenai perikanan cantrang yang berkaitan dengan sumber daya ikan demersal sebagai hasil tangkapan utama dilaksanakan selama tahun 2006 - 2007. Penelitian ini bertujuan untuk mengetahui fluktuasi bulanan hasil tangkapan cantrang yang berbasis di Pelabuhan Perikanan Pantai Tegal Sari. Metode yang digunakan adalah survei yang meliputi pengambilan contoh dari hasil tangkapan, pencatatan buku bakul dan statistik perikanan pelabuhan. Hasil penelitian menunjukkan bahwa jumlah trip armada cantrang periode 2006 - 2007 didominansi oleh kapal berukuran 21 - 30 GT. Produksi bulanan Pelabuhan Perikanan Pantai Tegal Sari dari tahun 2004 - 2007 berfluktuasi. Secara umum, produksi bulanan pada bulan Nopember 2005 - Desember 2006 jauh lebih tinggi dibanding pada bulan-bulan di tahun 2004 dan 2007. Hal ini karena dipengaruhi oleh fluktuasi jumlah trip dan perkembangan unit penangkapan. Komposisi hasil tangkapan cantrang tahun 2006 berdasarkan pada hasil pengambilan contoh, didominansi oleh ikan coklatan (Scolopsis taeniopterus) (22%), kuniran (Upeneus spp.) (17,4%), dan swangi atau demang (Priachantus sp.) (9,7%). Ratarata laju tangkap pada tahun 2006 dan 2007 berturut-turut 333,6 dan 424 kg/hari. Laju tangkap tahun 2006 cenderung, dipengaruhi oleh fluktuasi musiman, sedangkan laju tangkap tahun 2007 cenderung naik, tidak terpengaruh oleh fluktuasi musiman. Daerah penangkapan armada cantrang yang berbasis di Pelabuhan Perikanan Pantai Tegal Sari adalah di sekitar pantai timur Lampung, Tanjung Selatan (Kalimantan Selatan), dan Tanjung Puting (Kalimantan Tengah). The research on danish seine fishery related to demersal fish resources as the main catch was carried out from 2006 - 2007. The research aimed to know monthly fluctuation of the danish seine catch in Tegal Sari landing base. The survey was conducted by sampling the catch, recording data from retailer’s book and landing base statistic. The results showed that number of trip from 2006 - 2007 was dominated by 21 to 30 GT vessel. Monthly production in Tegal Sari landing base on 2004 to 2007 was fluctuated. Generally, monthly production on November 2005 - Desember 2006 was higher than other months on 2004 and 2007. It was caused by fluctuation of trips number and unit fishing developement. The catch composition in 2006 based on sampling result, was dominated by lattice monocle bream (Scolopsis taenipterus) (22%), goatfish (Upeneus spp.) (17.4%), and purple spotted bigeye (Priachantus spp.) (9.7%). Average of catch rate in 2006 and 2007 was 335.6 and 424 kg per day, respectively. The catch rate in 2006 danish seine, Tegal Sari tended to be influenced by season fluctuation. While catch rate in 2007 increased and was not influenced by season. Fishing grounds of danish seine fleet in Tegal Sari landing base were in eastern coast of Lampung waters, Tanjung Selatan (South Kalimantan) and Tanjung Puting (Central Kalimantan), respectively.


2020 ◽  
Vol 6 (2) ◽  
pp. 30-37
Author(s):  
Eko Setyo Budi

This study aims to determine the effect of the type of bait on the composition of the catch fish, catch rate, and trap rate using square folding traps. The study was conducted at three fishing locations in October 2019-January 2020 using the experimental fishing method. The operation of square folding traps was done by a total of 60 units. The types of bait used are golden snails, shrimp paste, and trash fish. Fish catches were recorded in number, type, length, and weight, and analyzed using one-way anova test and kruskal wallis test. The composition of the square folding traps catches consists of six species. Marble goby (Oxyeleotris marmorata) is the most dominant catch (60%). The highest catch rate was obtained from box folding traps which were given golden snail bait at 173.50 g/trip, then trash fish bait at 76.88 g/trip and shrimp paste feed at 59.22 g/trip. The highest trap rate is golden snail bait of 12.33%. The bait treatment gives a real difference to the amount and weight of the catch, the golden snail bait gives the highest total number and weight of the catch compared to other baits.


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