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1
Marshall, Eliot. "5.7% Increase Catches NIH By Surprise." Science 271, no. 5246 (January 12, 1996): 136. http://dx.doi.org/10.1126/science.271.5246.136.b.
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Marshall, Eliot. "5.7% Increase Catches NIH By Surprise." Science 271, no. 5246 (January 12, 1996): 136. http://dx.doi.org/10.1126/science.271.5246.136-b.
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Dinets, Vladimir. "Eastern Screech-Owl Catches Fish By Wading." Wilson Journal of Ornithology 123, no. 4 (December 2011): 846–47. http://dx.doi.org/10.1676/11-056.1.
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Jensen, J. W. "Evaluating catches of salmonids taken by gillnets." Journal of Fish Biology 46, no. 5 (May 1995): 862–71. http://dx.doi.org/10.1111/j.1095-8649.1995.tb01609.x.
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Sullivan, Michael G. "Exaggeration of Walleye Catches by Alberta Anglers." North American Journal of Fisheries Management 23, no. 2 (May 2003): 573–80. http://dx.doi.org/10.1577/1548-8675(2003)023<0573:eowcba>2.0.co;2.
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SCHWARTZ, FRANK J. "Long Term Long-Line Shark Catches: Variations by Site and Tidal Stage." Journal of North Carolina Academy of Science 127, no. 3 (October 1, 2011): 214–15. http://dx.doi.org/10.7572/2167-5880-127.3.214.
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Abstract Long term long-line shark catch variations (38 yr) at two Onslow Bay, North Carolina sites were examined for differences in catches by sites and tidal stages. Catches were highly significantly different between sites. Catches by tidal stage were not significantly different at each site.
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Liggins, GW, SJ Kennelly, and MK Broadhurst. "Observer-based survey of by-catch from prawn trawling in Botany Bay and Port Jackson, New South Wales." Marine and Freshwater Research 47, no. 7 (1996): 877. http://dx.doi.org/10.1071/mf9960877.
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Catches and by-catches were surveyed in the commercial prawn trawl fleets of Botany Bay and Port Jackson, two estuaries in the Sydney metropolitan area (NSW, Australia). Catches were surveyed in all tows during replicate fishing trips in each month during the 1990-91 and 1991-92 prawn trawl seasons in each estuary. Significant species-specific variabilities in abundances were detected between estuaries, between years, and between early and late in the fishing season. The mean annual ratio of by-catch to catch of prawns (by weight) was 2.5 : 1 for Botany Bay and 1.8 : 1 for Port Jackson. A mean annual by-catch (� 1 s.e.) of 142 � 14 t was taken from the Botany Bay fishery and 38 � 3 t from Port Jackson. These by-catches included large numbers of small recreationally and commercially important finfish: a mean annual by-catch of 1.52 �0.20 million fish from Botany Bay and 219� 23 thousand fish from Port Jackson. Despite uncertainties about the impacts of such by-catches on interacting commercial and recreational fisheries, it is recommended that strategies for the reduction of such by-catches be considered.
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Marshall, E. "Biomedical Research: 5.7% Increase Catches NIH By Surprise." Science 271, no. 5246 (January 12, 1996): 136b—136. http://dx.doi.org/10.1126/science.271.5246.136b.
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Niemelä, E., J. Erkinaro, M. Julkunen, and E. Hassinen. "Is juvenile salmon abundance related to subsequent and preceding catches? Perspectives from a long-term monitoring programme." ICES Journal of Marine Science 62, no. 8 (January 1, 2005): 1617–29. http://dx.doi.org/10.1016/j.icesjms.2005.07.002.
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Abstract The abundance of wild Atlantic salmon in the River Teno system has been monitored since the 1970s by estimating salmon catches and juvenile salmon densities at permanent electrofishing sites. Analysis of the time-series has shown significant relationships between juvenile densities (0+ and 1+) and subsequent 1SW and 2SW catches. Corresponding significant relationships have been detected between 1SW and 2SW female salmon in the catches and subsequent fry and parr densities. Monitoring juvenile densities allows evaluation of spawning escapement 1 and 2 years earlier, confirming the stock status information provided by catch statistics. These relationships between juvenile abundance and catches suggest that the monitoring programme has included feasible and biologically relevant variables and proper methodologies. Increasing trends were detected in the numbers of 1SW and 2SW salmon in catches between 1977 and 2003. Similarly, fry abundance indicated long-term increasing trends at most sites. Significant relationships were detected between abundances of subsequent sea-age groups in catches (1SW vs. 2SW 1 year later, etc.), indicating that strong smolt year classes influence the abundance of several subsequent sea-age groups, and that such relationships permit forecasting future catches of multi-sea-winter salmon by 1SW salmon catches.
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Leitão, Francisco, Vânia Baptista, and Karim Erzini. "Reconstructing discards profiles of unreported catches." Scientia Marina 82, S1 (December 20, 2018): 39. http://dx.doi.org/10.3989/scimar.04723.08a.
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In Portugal it has been estimated that unreported catches represent one third of total catches. Herein, information on landings and total unreported catches (discards) by commercial métier were disaggregated into high taxonomic detail using published scientific studies. Fish accounted for 93.5% (115493 t) of overall unreported catches per year, followed by cephalopods (2345 t, 1.9%) and crustaceans (1754 t, 1.4%). Sharks accounted for 1.3% of total unreported catches in weight (1638 t/y). Unreported taxa consisted mostly of the commercial landed fish species: Scomber colias, Boops boops, Trachurus picturatus, T. trachurus, Merluccius merluccius, Sardina pilchardus, Liza aurata and Micromesistius poutassou, which together accounted for 70% of the unreported discarded catches. The number of unreported/discarded species was highest in artisanal fisheries, followed by trawl and purse seine. In artisanal fisheries, L. aurata, S. colias, S. pilchardus, Trachinus draco and B. boops accounted for 76.4% of the unreported discards. B. boops, S. colias and S. pilchardus were also among the most discarded purse seine species, together with Belone belone accounting for 79% of the unreported catches. In trawl fisheries, T. picturatus (16%), M. merluccius (13%), S. colias (13%) and M. poutassou (13%) accounted for 55% of the trawl discarded unreported catches. The discarded species that most contribute to overall unreported catches are those that are most frequently landed and that most contribute to overall landings in weight.
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Lyach, Roman, and Jiri Remr. "The effects of environmental factors and fisheries management on recreational catches of perch Perca fluviatilis in the Czech Republic." Aquatic Living Resources 32 (2019): 15. http://dx.doi.org/10.1051/alr/2019013.
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The Eurasian perch Perca fluviatilis is an important fish species in both commercial and recreational fisheries. However, there is concern that perch populations in Central Europe are decreasing. This study aimed to assess the effects of environmental factors and management on recreational perch catches. Data from individual angling logbooks collected by the Czech Fishing Union on 229 fishing grounds during the period 2005–2016 were used in this study. In total, almost 60 000 perch weighing 17 500 kg were recorded. During the study period, total perch catches decreased by 60%, catch per fishing visit decreased by 70%, average body weight of caught perch increased by 18%, and percentage of fishing grounds with perch catches decreased by 13%. The results indicated that the decreasing catches were due to increasing fishing pressure. Further, fishing grounds with higher fishing visit rates had higher catches in general but lower catch per fishing visit. Larger and more productive rivers also showed higher catches. In contrast, the intensity of fish stocking did not affect catches. In conclusion, perch populations in Central Europe are likely under high fishing pressure, and the pressure is further increasing.
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Baylis, M., H. Parkin, K. Kreppel, Simon Carpenter, P. S. Mellor, K. Marie McIntyre, and Hélène Guis. "Evaluation de la stabulation comme moyen de protection des bovins des piqûres de Culicoides, vecteurs de la fièvre catarrhale ovine." Revue d’élevage et de médecine vétérinaire des pays tropicaux 62, no. 2-4 (February 1, 2009): 99. http://dx.doi.org/10.19182/remvt.10087.
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Light-trap catches of Culicoides biting midges were compared inside and outside animal housing, in the presence and in the absence of cattle. A three-time replicated 4x4 Latin square design was used at four farms in Bala, North Wales, over 12 nights in May and June; the experiment was repeated in October. In the two studies, over 70,000 and over 4500 Culicoides were trapped of which 93% and 86%, respectively, belonged to C. Obsoletus complex. Across the four farms, in May and June, the presence of cattle increased catches of C. obsoletus by 2.3 times, and outside traps caught them 6.5 times more than inside traps. Similar patterns were apparent in October, but the difference between inside and outside catches was reduced. Catches were strongly correlated with minimum temperature and maximum wind speed, and these two variables explained a large amount of night-to-night variation in catch. Outside catches were reduced to a greater extent than inside catches by colder minimum temperatures and stronger maximum wind speeds. These conditions occurred more frequently in October than in May and June, thereby suppressing the outside catches more than the inside catches, and reducing the apparent degree of exophily of C. obsoletus in autumn. The results suggest that the risk of animals receiving bites from C. obsoletus is reduced by housing at both times of year, but the benefit would be greatest on warm, still nights when outside catches are at their greatest.
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Lines, J. D., C. F. Curtis, T. J. Wilkes, and K. J. Njunwa. "Monitoring human-biting mosquitoes (Diptera: Culicidae) in Tanzania with light-traps hung beside mosquito nets." Bulletin of Entomological Research 81, no. 1 (March 1991): 77–84. http://dx.doi.org/10.1017/s0007485300053268.
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AbstractMosquitoes were caught in bedrooms in Tanzanian villages by human-biting catches and in light-traps set close to occupied untreated bed nets. Catches by each method were carried out on pairs of nights in the same week at different seasons and in different villages. The pairs of adjacent catches by the different methods showed a strong correlation. Analysis of the ratio between the catches by the two methods on pairs of nights in the same week indicated that on average three light-traps caught about the same number of mosquitoes as a team of two human catchers. The ratio did not differ significantly between Anopheles gambiae Giles (sensu lato), A. funestus Giles, and Culex quinquefasciatus Say, nor between the villages, or between times when mosquito populations were high or low. The distribution of numbers of ovarian dilatations differed significantly between catches in different villages and seasons but not between pairs of catches by the two methods. Similarly, the parity and sporozoite rates agreed between pairs of light-trap and house-resting catches, but differed markedly between villages and seasons. Thus it is concluded that light-traps used in conjunction with bed nets catch a representative sample of the vectors which would have bitten humans in bedrooms in this area.
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Carlson, Andrew K., William W. Taylor, Daniel I. Rubenstein, Simon A. Levin, and Jianguo Liu. "Global Marine Fishing across Space and Time." Sustainability 12, no. 11 (June 9, 2020): 4714. http://dx.doi.org/10.3390/su12114714.
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Human health and livelihoods are threatened by declining marine fisheries catches, causing substantial interest in the sources and dynamics of fishing. Catch analyses in individual exclusive economic zones (EEZs) and the high seas are abundant, and research across multiple EEZs is growing. However, no previous studies have systematically compared catches, intranational versus international fish flows, and fishing nations within all of the world’s EEZs and across adjacent and distant EEZs and the high seas to inform “metacoupled” fisheries management. We use the metacoupling framework—a new approach for evaluating human–nature interactions within and across adjacent and distant systems (metacouplings)—to illustrate how fisheries catches were locally, regionally, and globally interconnected in 1950–2014, totaling 5.8 billion metric tons and increasing by 298% (tonnage) and 431% (monetary value) over this time period. Catches by nations in their own EEZs (largest in Peru) and adjacent EEZs (largest in Indonesia) constituted 86% of worldwide catches, growing in 1950–1996 but declining in 1997–2014. In contrast, catches in distant EEZs and the high seas—largest in Morocco, Mauritania, and Canada—peaked in 1973 and have since represented 9–21% of annual catches. Our 65-year, local–regional–global analysis illustrates how metacoupled fisheries governance—holistic management of multiscalar catches, flows, and tradeoffs within and among fisheries—can improve food and nutrition security, livelihood resilience, and biodiversity conservation across the world.
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KHALFALLAH, M., M. DIMECH, A. ULMAN, D. ZELLER, and D. PAULY. "Reconstruction of Marine Fisheries Catches for the Republic of Malta (1950-2010)." Mediterranean Marine Science 18, no. 2 (July 17, 2017): 241. http://dx.doi.org/10.12681/mms.1683.
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The marine fisheries catches of Malta were reconstructed for the period 1950-2014, including for reported and previously unreported commercial large- and small-scale catches, unmonitored fisheries catches, i.e., subsistence and recreational fisheries, as well as major discards. The present study updates and improves a previous catch reconstruction for Malta for the 1950-2010 time period. Reconstructed marine fisheries catches for Malta are nearly 1.3 times the official landings reported by the FAO and national authorities on behalf of Malta, increasing from around 1,200 t·year-1 in the 1950s to 3,700 t·year-1 in the 2010s. The discrepancy between reported and reconstructed total catches is mostly due to the subsistence catches estimated, which here consist exclusively of on-board consumption and take-home catch of commercial fishers. While the Maltese fisheries statistical system includes procedures to estimate ‘unmonitored’ commercial landings, this contribution documents that it would be beneficial to also account for non-commercial catches.
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Stassen, Marinke J. M., Max W. P. M. van de Ven, Tjisse van der Heide, Marco Antonio Guerrero Hiza, Gerard van der Velde, and Alfons J. P. Smolders. "Population dynamics of the migratory fish Prochilodus lineatus in a neotropical river: the relationships with river discharge, flood pulse, El Niño and fluvial megafan behaviour." Neotropical Ichthyology 8, no. 1 (February 26, 2010): 113–22. http://dx.doi.org/10.1590/s1679-62252010005000006.
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The relative importance of flood pulse dynamics and megafan behaviour for the Sábalo (Prochilodus lineatus) catches in the neotropical Pilcomayo River is studied. The Sábalo catches can mainly be explained by decreased river discharges in the preceding years resulting in smaller inundated areas during rainy season floods and thereby in a decreased area of feeding grounds for the fishes. The decreased river discharges and the related decline of Sábalo catches in the 1990's can be linked to the 90-95 El Niño event. In 2007 the Sábalo catches were comparable to the catches before the "El Niño" event. The connectivity (continuity) between the main river and flood plain areas, which is influenced by sedimentation processes, is also of great importance and very probably plays a more important role since the late 1990's.
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Somers, Keith M., and Roger H. Green. "Seasonal patterns in trap catches of the crayfish Cambarus bartoni and Orconectes virilis in six south-central Ontario lakes." Canadian Journal of Zoology 71, no. 6 (June 1, 1993): 1136–45. http://dx.doi.org/10.1139/z93-155.
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Crayfish were trapped in six south-central Ontario lakes to examine seasonal changes in estimates of relative abundance. Baited-trap catches of Cambarus bartoni and Orconectes virilis correlated with changes in water temperature. Cambarid catches increased in the spring until a midsummer maximum, but dropped suddenly as the water temperature began to fall in August. Ovigerous (i.e., egg-bearing) females and recently moulted males were captured by SCUBA divers in August. Trap catches increased, once breeding and moulting periods concluded, and subsequently decreased as water temperatures continued to drop in the autumn. In contrast, catches of male O. virilis increased in the spring and remained relatively constant throughout the summer until water temperatures fell in September. Catches of female O. virilis peaked somewhat later in the summer and then gradually declined in the early fall. Although the two species and the two sexes differed in the length of the midsummer sampling period when trap catches were relatively constant, similar seasonal trends among lakes suggest that midsummer trap catches can be used to estimate crayfish relative abundance. Other factors, such as the presence of smallmouth bass (Micropterus dolomieui), lake physical and chemical characteristics, and the number of co-occurring crayfish species also correlated with trap catches. Both the presence of bass and the number of co-occurring species of crayfish probably affect crayfish behaviour and activity, thereby reducing catches in baited traps, but not necessarily affecting actual population abundance. Comparisons of relative abundance based on catches from baited traps must control for these seasonal behavioural, and environmental factors.
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Strehlow, Harry V., Norbert Schultz, Christopher Zimmermann, and Cornelius Hammer. "Cod catches taken by the German recreational fishery in the western Baltic Sea, 2005–2010: implications for stock assessment and management." ICES Journal of Marine Science 69, no. 10 (December 1, 2012): 1769–80. http://dx.doi.org/10.1093/icesjms/fss152.
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Abstract Strehlow, H. V., Schultz, N., Zimmermann, C., and Hammer, C. 2012. Cod catches taken by the German recreational fishery in the western Baltic Sea, 2005–2010: implications for stock assessment and management. – ICES Journal of Marine Science, 69: 1769–1780. Next to the commercial fishery, the recreational fishery plays an important role in the removal of biomass from fish stocks. In this study, we present estimates of German recreational cod (Gadus morhua) catches in the western Baltic Sea between 2005 and 2010. Fishing effort was estimated using a stratified mail survey and annual sales of fishing licences. Catch per unit effort was estimated by stratified random sampling of access points and interviews about completed trips. Length distributions of cod catches were acquired by sampling recreational cod catches from charter boats and data from community fishing events. Estimates of the total cod biomass removed by the recreational fishery fluctuated between 2159 t in 2009 and 4127 t in 2005. Annual recreational fishery cod harvests accounted for a significant share of the total landings, with a yearly variation from 34 to 70% of the German commercial cod landings from the western Baltic Sea. The majority of recreational fishery cod catches were taken from private boats and charter vessels. Because of the amount and specifically the variability of the recreational catches, they are important for the assessment and management of the resource and, therefore, need to be surveyed annually.
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Moszynski, P. "Return of refugees to Afghanistan catches agencies by surprise." BMJ 325, no. 7370 (October 26, 2002): 924. http://dx.doi.org/10.1136/bmj.325.7370.924.
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Treer, Tomislav. "Decline of Artisanal Fish Catch by Species in the Croatian Section of the Sava River." Croatian Journal of Fisheries 82, no. 1 (March 1, 2024): 43–47. http://dx.doi.org/10.2478/cjf-2024-0005.
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Abstract The aim of this study is to analyse the development of artisanal fish catch by species in the Croatian section of the Sava River. For Abramis brama and Silurus glanis, a significant decline in catches (in kg) was observed throughout the study period (2004-2021). Since 2013, this has also been the case for Cyprinus carpio, Esox lucius, Sander lucioperca, other autochthonous species and alochthonous species, while catches of Leuciscus idus have declined significantly since 2014. The catches of three species (Acipenser ruthenus, Leuciscus aspius and Tinca tinca) fluctuated without a trend, which can be attributed to the low quantities. This decline in catches of the most sought-after species in the Sava was greater than that of the other less sought-after autochthonous species (mainly other cyprinids), whose share of the total catch increased significantly.
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Velikanov, A. Ya. "History of the pacific capelin Mallotus catervarius (osmeriformes) fishery near the sakhalin coast and reasons of its catch records in present period." Problems of Fisheries 25, no. 1 (March 7, 2024): 29–48. http://dx.doi.org/10.36038/0234-2774-2024-25-1-29-48.
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Far East capelin is characterized by long-term cycles of its biomass dynamics. During XX and early XXІ century fishery of Far East capelin near Sakhalin Island was more intensive in the years of high abundance. In 1930s annual catches of this fish was not more than 0,8– 0,9 thousand tons. In 1970s catches varied from 0,93 to 2,50 thousand tons. In 2016–2022 capelin catches attained to record level, 3,5–13,7 thousand tons. Grate catches connected by complex reasons such as large spawning biomass, intensive fishery and its season near Sakhalin coast and some others. It is already clear that the northwestern coast of Sakhalin is the most ideal for reproduction, growth, and survival of capelin in the waters around Sakhalin Island. Reproduction productivity of this fish species in the Sakhalin area of Okhotsk Sea is much lower as an annual catches.
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Heide-Jørgensen, MP, and A. Rosing-Asvid. "Catch statistics for belugas in West Greenland 1862 to 1999." NAMMCO Scientific Publications 4 (July 21, 2002): 127. http://dx.doi.org/10.7557/3.2840.
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Information and statistics including trade statistics on catches of white whales or belugas (Delphinapterus leucas) in West Greenland since 1862 are presented. The period before 1952 was dominated by large catches south of 66o N that peaked with 1,380 reported kills in 1922. Catch levels in the past five decades are evaluated on the basis of official catch statistics, trade in mattak (whale skin), sampling of jaws and reports from local residents and other observers. Options are given for corrections of catch statistics based upon auxiliary statistics on trade of mattak, catches in previous decades for areas without reporting and on likely levels of loss rates in different hunting operations. The fractions of the reported catches that are caused by ice entrapments of whales are estimated. During 1954-1999 total reported catches ranged from 216 to 1,874 and they peaked around 1970. Correcting for underreporting and killed-but-lost whales increases the catch reports by 42% on average for 1954-1998. If the whales killed in ice entrapments are removed then the corrected catch estimate is on average 28% larger than the reported catches.
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Schwedeer, Tore, and Gro Hagen. "A note on the cost of instability in whale management." J. Cetacean Res. Manage. 1, no. 2 (January 25, 1999): 136–40. http://dx.doi.org/10.47536/jcrm.v1i1.459.
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The history of whaling has been characterised by considerable variation in management 'philosophy'. For example, an early period of overexploitation led eventually to the present period of protectionism and might be followed by a period of excessive catches. Is such instability in long-term management costly? The risk of depletion increases with increasing instability. If the net production function governing whale dynamics is essentially convex, it is demonstrated that long-term catches are necessarily smaller the greater the management instability. A simulation experiment is carried out to quantify the loss in whale catches due to •stop-go' instability in whale management. To examine possible costs in terms of fisheries for cod and herring, a multi-species simulation model is used, with minke whales managed by a stochastic stop-go procedure and with cod, herring and capelin managed by VPA-type procedures. In the simulations, whale catches are reduced by increased instability in whale management while long-term catches of cod and herring are unaffected, provided mean whale abundance is kept fixed.
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Bracalini, Matteo, Francesco Croci, Emanuele Ciardi, Giulio Mannucci, Emanuele Papucci, Giulia Gestri, Riziero Tiberi, and Tiziana Panzavolta. "Ips sexdentatus Mass-Trapping: Mitigation of Its Negative Effects on Saproxylic Beetles Larger Than the Target." Forests 12, no. 2 (February 3, 2021): 175. http://dx.doi.org/10.3390/f12020175.
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Research Highlights: We investigated the negative effects of bark beetle mass trapping, especially non-target catches among the target’s natural enemies. Slot traps modified with mesh screen and escape windows were tested to improve their selectiveness. Background and Objectives: Two of the main natural enemies of bark beetles, Thanasimus formicarius (L.) and Temnoscheila caerulea (Olivier), are frequently trapped in high numbers in Ips sexdentatus (Böerner) pheromone traps, along with other saproxylic insects; this may lead to much larger pest populations in the successive 4–20 beetle generations. From 2016–2019, during I. sexdentatus mass-trapping in a pine forest of Tuscany (Italy), non-target catches were tallied. Trap modifications were evaluated to mitigate non-target catches, especially those concerning bark beetles’ natural enemies. Materials and Methods: A total of 25 bark-beetle slot traps were placed about 75 m apart in a pine stand infested by I. sexdentatus. Traps were baited with I. sexdentatus aggregation pheromone, whose main components are ipsenol, ipsdienol, and 2-methyl-3-buten-2-ol. Catches were collected every 10 days from March to December. In 2019, 13 traps were modified by applying a 6-mm mesh screen on top of the collection container and by providing three 60 mm × 8 mm escape windows immediately above the screen. These “modified traps” and their captures were considered separately from the 12 remaining “standard traps.” All bark beetle species were recorded, as well as all beetle species > 8 mm. Results: Overall, target catches amounted for <10% of the total beetle catches. The most-collected species was the bark beetle Orthotomicus erosus Wollaston. Trap modification allowed the escape of larger species, resulting in the reduction of the average size of caught specimens. Even though non-target catches among predators were still high, the proportion of major predators (T. formicarius and T. caerulea) to bark beetles showed a statistically significant reduction of predator catches in modified traps, an encouraging outcome. Conclusions: Trap modifications may mitigate the problem of non-target catches during mass trapping, especially reducing catches of beetle species larger than the target. However, the key is to schedule mass trapping only during those seasons when the target adults are more active than the main predator adults, thus limiting their catches and, consequently, the negative effects on pest management and biodiversity.
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Jaaman, Saifullah A., Yuhana U. Lah-Anyi, and Graham J. Pierce. "The magnitude and sustainability of marine mammal by-catch in fisheries in East Malaysia." Journal of the Marine Biological Association of the United Kingdom 89, no. 5 (September 23, 2008): 907–20. http://dx.doi.org/10.1017/s002531540800249x.
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The magnitude and sustainability of incidental catches of marine mammals in fisheries was investigated in Sabah and Sarawak, East Malaysia, using a combination of interview surveys and observer trips on fishing boats. These fisheries involve around 15,000 registered fishing boats and generate annual landings of around 350,000 tonnes. Between March 1997 and December 2004, we interviewed fishermen working on 753 and 358 boats in Sabah and Sarawak, respectively, who were employing trawl nets, purse seines, gillnets and fish stakes. They were asked questions about sightings of marine mammals and interactions with fishing. We also followed 36 trawl and 10 purse seine fishing trips in Sabah between June 2003 and December 2004. Fishing was conducted in coastal waters and total annual catches by each method and region were estimated. Incidental catches of marine mammals were reported by fishermen from 310 (41%) and 99 (28%) fishing boats in Sabah and Sarawak, respectively. Gill-netters, trawlers and fish stakes were reported to catch cetaceans and dugongs, while purse seiners caught only cetaceans. The Irrawaddy dolphin, bottlenose dolphin, spinner dolphin, pantropical spotted dolphin, Indo-Pacific humpback dolphin and finless porpoise are the cetacean species known to be taken. Overall, the magnitude of incidental catches of marine mammals is greatest in gillnets. No marine mammal catches were seen during observer trips. Interview results suggest annual by-catches of 306 (95% CI = 250–369) cetaceans and 479 (95% CI = 434–528) dugongs in Sabah. Estimates for Sarawak were 221 (95% CI = 189–258) cetaceans per year and 14 (95% CI = 2–30) dugongs. These results suggest that by-catch rates, particularly in gillnets, may be unsustainably high. A dedicated monitoring and educational programme, together with the establishment of Marine Protected Areas, is urgently needed to minimize the threat.
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Trella, Marek, and Arkadiusz Wołos. "Size and selected characteristics of northern pike (Esox lucius L.) commercial and angling catches in Polish inland waters over the long term." Fisheries & Aquatic Life 29, no. 2 (June 1, 2021): 108–23. http://dx.doi.org/10.2478/aopf-2021-0013.
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Abstract Northern pike (Esox lucius L.) is of great importance to inland commercial and recreational fisheries in Poland. Thanks to northern pike’s substantial size, strength, the possibility of using a variety of fishing methods and techniques and various baits, and many other values, lake anglers value this species above all others. Additionally, for over a decade, northern pike has been the most widely stocked species in Polish inland waters of lakes, rivers and dam reservoirs. The aim of this work was to analyze in detail the size and characteristics of northern pike commercial fisheries and angling catches in Polish inland waters over the long term. The analyses were based on a compilation of traditional scientific papers, primarily analyses of commercial catches, and a review of the results of more than 40 years of studies on the size of northern pike angling catches. The analysis of research material indicated a steady decrease in commercial catches of this species in the years State Fisheries Enterprises (SFE) were in operation followed by relative stability in catches over the past two decades. The paper describes the methods used to estimate angling catches, namely questionnaire and catch-return (the so-called register) research. An increasing disproportion between the sizes of pike catches made with angling and commercial fishing gear was documented. Despite the problems presented in the paper related to estimating total pike catches, the analysis revealed that anglers catch eightfold more northern pike than do commercial fishers.
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Nur Alfathia Artanti, Salmiya, Vivid Dekanawati, and Ningrum Astriawati. "Distribusi Dan Logistik Hasil Tangkapan Nelayan: Studi Kasus Pada Pelabuhan Perikanan Puger Jember." Jurnal Sains Teknologi Transportasi Maritim 4, no. 1 (May 30, 2022): 14–21. http://dx.doi.org/10.51578/j.sitektransmar.v4i1.44.
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Indonesian fishery products must be able to follow the requirements for guarantee good quality and the security the customer need to compete in the international market for distribution and logistics of fishermen's catches. This study aims to determine the distribution activity system of fishermen's catches on land in Pelabuhan Perikanan Pantai (PPP) Puger and Tempat Pelelangan Ikan (TPI) Puger and to determine the distribution of catches in Puger’s port. The research method used is field research using descriptive methods. The sampling technique in this study used a purposive sampling technique. The results showed that the distribution activity system for fishermen's catches on land at PPP Puger and TPI Puger was divided into 3 (three) stages, starting from when the catch was landed, stored and then transported to the destination. The distribution of catches in PPP Puger shows that the most catches are distributed outside the region are 30%, the second largest distribution is to wholesale diluents, which is 29%, while distribution to cities and villages is 20%, distribution to diluents is 15%, and the lowest distribution to consumers by 6%.
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Ivashchenko, Yulia, Phillip Clapham, and Robert Brownell Jr. "New data on Soviet catches of blue (Balaenoptera musculus) and right whales (Eubalaena japonica) in the North Pacific." J. Cetacean Res. Manage. 17, no. 1 (January 24, 2023): 15–22. http://dx.doi.org/10.47536/jcrm.v17i1.427.
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Details are provided on 17 previously unreported catches of blue whales, and 93 catches of North Pacific right whales, all taken illegally by the former USSR. The blue whale catches were made between mid-July and mid-September 1972 in the eastern North Pacific at distances of from 96 to 626 nautical miles from the US west coast (Oregon and Washington); they highlight the inadequacy of the International Observer Scheme, as implemented in 1972, to report or detect illegal whaling. These previously unknown blue whale catches bring the Soviet total to 1,638 for the period 1948–1972. The 93 right whale catches were made during the period 1951–62 around the Kuril Islands, which brings the known total of takes of this species from 1935–1971 to 775 (including 10 taken for scientific research and officially reported at the time).
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Ponomareva, Elena Nikolaevna, Pavel Aleksandrovich Balykin, Alexander Veniaminovitch Startsev, Alexander Aleksandrovich Korchunov, and Svetlana Sergeevna Savitskaya. "Current state of fisheries in the Volga-Caspian subarea." Vestnik of Astrakhan State Technical University. Series: Fishing industry 2022, no. 3 (September 30, 2022): 7–15. http://dx.doi.org/10.24143/2073-5529-2022-3-7-15.
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Analysis of the current state of fisheries in the Volga-Caspian subarea has been carried out. The processes
of deformation of aquatic biological resources of the Caspian basin have been assessed. Modern catches of commercial fish have decreased by one order of magnitude compared to the last century. At the beginning of the 20th century the stocks of semi-anadromous and river fish species were significant, the catches reached 200-300 thousand tons. In recent years, the catch of the fish has stabilized at the level of 36.0-43.3 thousand tons. In recent years the catches of vobla, carp and zander were the lowest in the history of the Caspian fisheries. The catch of carp, compared with that in the 1980s, decreased by more than 5 times, vobla – by 6 times, zander – by 4 times. Since 2003, there has been a decrease in the catch of bream up to 7-10 thousand tons. A sharp decrease in catches is primarily explained by the collapse of kilka stocks. There is an acute problem of limiting and even a complete ban on fishing vobla. According to the results of the correlation analysis (comparison of the values of natural factors with the value of catches in the studied subareas), it was found that fish production in the Volga-Caspian subarea does not show any relationship with any of the listed natural factors. An analysis of the species composition of semi-anadromous and river fish caught by various fishing gear in the Lower Volga was carried out. The species composition of catches by secrets is more diverse than by cast nets and gillnets. Most abundant species in the catches are bream, vobla, pike, catfish, rudd. A forecast is given for a further fishery reduction in the Caspian basin including the Astrakhan region.
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Vale, G. A., and D. R. Hall. "The use of 1-octen-3-ol, acetone and carbon dioxide to improve baits for tsetse flies, Glossina spp. (Diptera: Glossinidae)." Bulletin of Entomological Research 75, no. 2 (June 1985): 219–32. http://dx.doi.org/10.1017/s0007485300014309.
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AbstractIn Zimbabwe, the catches of Glossina morsitans morsitans Westwood and G. pallidipes Austen in traps were increased by up to three times by releasing 1-octen-3-ol at 0·05–50 mg/h or acetone at 5–5000mg/h near traps, but in some circumstances 1-octen-3-ol at 5–50 mg/h reduced catches. Carbon dioxide at 0·02–20 litres/min increased catches by up to ten times. A mixture of all three chemicals increased the catches by up to 60 times. Each of the three chemicals attracted both species of flies from a distance; carbon dioxide also enhanced trap-entering and alighting responses. Acetone with 1-octen-3-ol can increase by several times the numbers of flies that contact visual baits suitable for exposing them to insecticide. Data for other Diptera are also presented.
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Rodwell, Lynda D., Edward B. Barbier, Callum M. Roberts, and Tim R. McClanahan. "The importance of habitat quality for marine reserve fishery linkages." Canadian Journal of Fisheries and Aquatic Sciences 60, no. 2 (February 1, 2003): 171–81. http://dx.doi.org/10.1139/f03-009.
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We model marine reserve fishery linkages to evaluate the potential contribution of habitat-quality improvements inside a marine reserve to fish productivity and fishery catches. Data from Mombasa Marine National Park, Kenya, and the adjacent fishery are used. Marine reserves increase total fish biomass directly by providing refuge from exploitation and indirectly by improving fish habitat in the reserve. As natural mortality of the fish stock decreases in response to habitat enhancement in the reserve, catches increase by up to 2.6 tonnes (t)·km2·year1 and total fish biomass by up to 36 t·km2. However, if habitat-quality improvement reduces the propensity of fish to move out of the reserve, catches may fall by up to 0.9 t·km2·year1. Our results indicate that habitat protection in reserves can underpin fish productivity and, depending on its effects on fish movements, augment catches.
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Gray, Charles A. "Spatial variation in by-catch from a prawn seine-net fishery in a south-east Australian coastal lagoon." Marine and Freshwater Research 52, no. 7 (2001): 987. http://dx.doi.org/10.1071/mf00121.
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Observer-based estimates of the catches and by-catches from prawn seining (locally termed ‘snigging’) in Tuggerah Lake (NSW, Australia) during the 1998/99 fishing season are presented. Observed catches included three species of penaeid prawns, while observed by-catches contained a total of 49 finfish and 5 invertebrate taxa. The overall by-catch:prawn catch ratio by weight was 0.9:1, and in catching an estimated 20 ± 4 t of prawns the fleet took an estimated total by-catch of ± 2 t throughout the 6-month fishing season. The by-catch included large numbers of small (<15 cm total length) finfish species important in other commercial and recreational fisheries, including Gerres subfasciatus,Rhabdosargus sarba and Acanthopagrus australis, as well as several small demersal species of little economic value. Multivariate analyses indicated that by-catch composition differed between seines taken over shallow seagrass and bare substrata, with catch rates of several species being greater over seagrass. It is recommended that strategies to reduce potential ecological impacts and by-catch in this fishery be investigated, including fixed spatial closures over seagrasses and the development of alternative fishing gears and practices.
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Gordon, J. D. M., and O. A. Bergstad. "Species composition of demersal fish in the Rockall Trough, north-eastern Atlantic, as determined by different trawls." Journal of the Marine Biological Association of the United Kingdom 72, no. 1 (February 1992): 213–30. http://dx.doi.org/10.1017/s002531540004889x.
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The variation in species composition of continental slope fishes as determined by the catches of different trawls towed either on single or paired warps was analysed by Detrended Correspondence Analysis (DCA). The catches of two trawls, a semi-balloon trawl (OTSB) and a Granton trawl (GT) were very similar when towed on paired warps. Significant differences were found between the catches of the OTSB trawl towed on single and paired warps. The DCA effectively provided information on the important gradients, e.g. depth, trawl type, and indicated which species were most abundant in the different depth zones and trawl types. Detailed accounts of the abundance and biomass of different species by trawl type and depth zone are given and the observed pattern of distribution discussed.
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Lomeli, Mark J. M., Scott D. Groth, Matthew T. O. Blume, Bent Herrmann, and W. Waldo Wakefield. "Effects on the bycatch of eulachon and juvenile groundfish by altering the level of artificial illumination along an ocean shrimp trawl fishing line." ICES Journal of Marine Science 75, no. 6 (August 13, 2018): 2224–34. http://dx.doi.org/10.1093/icesjms/fsy105.
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Abstract We examined how catches of ocean shrimp (Pandalus jordani), eulachon (Thaleichthys pacificus), and juvenile groundfish could be affected by altering the level of artificial illumination along the fishing line of an ocean shrimp trawl. In the ocean shrimp trawl fishery, catches of eulachon are of special concern, as the species’ southern Distinct Population Segment is listed as “threatened” under the US Endangered Species Act. Using a double-rigged trawl vessel, with one trawl illuminated and the other unilluminated, we compared the catch efficiencies for ocean shrimp, eulachon, and juvenile groundfish between an unilluminated trawl and trawls illuminated with 5, 10, and 20 LED fishing lights along their fishing line. The addition of artificial illumination along the trawl fishing line significantly affected the average catch efficiency for eulachon, rockfish (Sebastes spp.), and flatfish, with the three LED configurations each catching significantly fewer individuals than the unilluminated trawl without impacting ocean shrimp catches. For Pacific hake (Merluccius productus), the ten LED-configured trawl caught significantly more fish than the unilluminated trawl. For the five and 20 LED configurations, mean Pacific hake catches did not differ from the unilluminated trawl. This study contributes new data on how artificial illumination can affect eulachon catches (and other fish) and contribute to their conservation.
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van Oostenbrugge, J. A. E., E. J. Bakker, W. L. T. van Densen, M. A. M. Machiels, and P. A. M. van Zwieten. "Characterizing catch variability in a multispecies fishery: implications for fishery management." Canadian Journal of Fisheries and Aquatic Sciences 59, no. 6 (June 1, 2002): 1032–43. http://dx.doi.org/10.1139/f02-078.
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Exploiting several fish species simultaneously reduces variability in daily catches. The reduction depends on the number of species, the catch-frequency distributions of individual species, and the level of co-occurrence of species in the catch. We explore theoretically the reduction of variability (coefficient of variation; CV) in the total catch by combining the distributions of daily catches of individual fish species, including zero catches, into a total catch frequency distribution. Theoretical findings are tested with an example from a stationary lift-net fishery for schooling small pelagic species around Ambon Island in the Central Moluccas, Indonesia. This fishery catches over 30 species, all with high daily variability (CV = 2.213.4). The reduction of variability in the total catch (CV = 1.7) is a result of the dominance and independent occurrence of the three main species. We conclude that in this fishery the information value of the total catch as an indicator of the catches of the individual species is low.
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Machado, Alexandre M. S., Eduardo L. Hettwer Giehl, Luiza Pacheco Fernandes, Simon N. Ingram, and Fábio G. Daura-Jorge. "Alternative data sources can fill the gaps in data-poor fisheries." ICES Journal of Marine Science 78, no. 5 (April 16, 2021): 1663–71. http://dx.doi.org/10.1093/icesjms/fsab074.
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Abstract Assessing fish stocks harvested by small-scale fisheries is challenging. The lack of official fisheries data constrains the proper management of such fisheries. Thus, alternative sources of information are crucial to enrich data-poor fisheries. Here, we evaluated different sources of data for the mullet (Mugil liza) fishery, one of the most important but overexploited fisheries in Brazil. We gathered three alternative sources of catch data by artisanal fisheries: 14 years of self-reported catches by artisanal fishers across 24 municipalities; 16 years of catches by traditional beach seines mined from news outlets; and 13 years from a single community monitoring their beach seine catches. We tested whether alternative data sources follow the same trends of landing reports from systematic, official monitoring of the industrial fleet. We fitted Bayesian time-series models to test if environmental changes and stock abundance can predict these data. We found that only self-reported catches matched the official reporting trends, thereby improving our understanding of changes in the mullet stock. These findings reveal that self-reported catches by fishers provide reliable additional data useful for management. Self-reporting data are cost-effective, deals with the complexity of small-scale fisheries, and welcomes fishers as key stakeholders in management practices.
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White, William T., Leontine Baje, Sharon A. Appleyard, Andrew Chin, Jonathan J. Smart, and Colin A. Simpfendorfer. "Shark longline fishery of Papua New Guinea: size and species composition and spatial variation of the catches." Marine and Freshwater Research 71, no. 6 (2020): 627. http://dx.doi.org/10.1071/mf19191.
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This study provides the first detailed investigation of the catches of the shark longline fishery in Papua New Guinea. Fisheries observers collected data on shark catches from a total of 318 longline sets between May and June 2014, before its closure in July 2014. In all, 14694 sharks were recorded with a total estimated biomass of 439 tonnes (Mg). Eighteen species of sharks were recorded in the observer data, with the most dominant species being Carcharhinus falciformis, which constituted more than 90% of the total catches by both weight and number of individuals. The level of observer misidentification was low (<10%), which reflected the use of region-specific identification guides by well-trained fisheries observers. The most diverse catches were in the Solomon Sea area, whereas catches in most other areas, particularly the Bismarck Sea areas, were less diverse and more strongly dominated by C. falciformis. Size and sex ratios varied by species, highlighting the importance of obtaining species-level information from the fishery being investigated. Any consideration by fisheries managers to reopen this fishery needs to consider the effect this will have on the species targeted and the livelihoods of coastal fishers who also rely on the same resources.
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Vale, G. A., D. R. Hall, and A. J. E. Gough. "The olfactory responses of tsetse flies, Glossina spp. (Diptera: Glossinidae), to phenols and urine in the field." Bulletin of Entomological Research 78, no. 2 (June 1988): 293–300. http://dx.doi.org/10.1017/s0007485300013055.
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AbstractIn Zimbabwe, catches of Glossina morsitans morsitans Westwood and G. pallidipes Austen in traps baited with acetone and 1-octen-3-ol were increased by the addition of the synthetic mixture of eight phenols found in cattle urine to a level equal to or greater than those with natural urine. The addition of natural urine to the synthetic mixture did not increase catches further, indicating that the phenols account for essentially all the attractiveness of cattle urine. 4-Methylphenol and 3-n-propylphenol were shown to be the naturally-occurring components essential for attractiveness, and 2-methoxyphenol was found to reduce attractiveness. 4-Methylphenol alone was slightly attractive to both species, but only for males, increasing catches by approximately 30%. Catches of both species were increased by approximately 50% by 3-n-propylphenol. The addition of 4-methylphenol increased catches of G. pallidipes by up to a further four times, but catches of G. m. morsitans were decreased. Of 14 other phenols tested, phenol, 3-methylphenol and 4-ethylphenol increased the attractiveness of 3-n-propylphenol to G. pallidipes without decreasing the attractiveness to G. m. morsitans; (E)- and (Z)-3-(1-propenyl)phenol, potential contaminants in 3-n- propylphenol, did not reduce the attractiveness of mixtures of 3-n-propylphenol and 4-methylphenol, and the E and, to a lesser extent, the Z isomer could substitute for 3-n-pro-pylphenol in these mixtures. Mixtures of phenols which increased the attractiveness of traps to tsetse showed similar effects with targets but at a slightly reduced level.
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Tuck, Geoffrey N., Tom Polacheck, John P. Croxall, and Henri Weimerskirch. "Modelling the impact of fishery by-catches on albatross populations." Journal of Applied Ecology 38, no. 6 (December 2001): 1182–96. http://dx.doi.org/10.1046/j.0021-8901.2001.00661.x.
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Jeffries, Perry, Aimee Keller, and Stephen Hale. "Predicting Winter Flounder (Pseudopleuronectes americanus) Catches by Time Series Analysis." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 4 (April 1, 1989): 650–59. http://dx.doi.org/10.1139/f89-083.
Full textAbstract:
Long-term changes in catches of winter flounder (Pseudopleuronectes americanus) were compared at five locations within Narragansett Bay, Rhode Island, USA and in three areas directly offshore. In the lower Bay, relative abundance decreased 86% during warming in the early 1970's, recovered briefly, and then declined to an all-time low in 1986. Time-series analysis successfully predicted a recovery in 1987. Year ahead predictions, based on annual models, had a maximum error of 14% (1986); monthly forecasts explained 62–72% of catch variation during the entire investigation; cumulative monthly error (forecast compared with actual over an annual cycle) was 11% in the Bay and 21% offshore. Commercial offshore catch and the fish retained on power plant intake screens in two major rivers showed the same 11-yr pattern of population fall and recovery detected in the lower Bay. Coherent behavior was also demonstrated by the similarity of random processes which generated the time-series data. Thus a single time-series model for southern New England winter flounder seems feasible.
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Brose, Ulrich. "Estimating species richness of pitfall catches by non-parametric estimators." Pedobiologia 46, no. 2 (January 2002): 101–7. http://dx.doi.org/10.1078/0031-4056-00117.
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Ganzedo, U., E. Zorita, A. P. Solari, G. Chust, A. Santana del Pino, J. Polanco, and J. J. Castro. "What drove tuna catches between 1525 and 1756 in southern Europe?" ICES Journal of Marine Science 66, no. 7 (March 28, 2009): 1595–604. http://dx.doi.org/10.1093/icesjms/fsp050.
Full textAbstract:
Abstract Ganzedo, U., Zorita, E., Solari, A. P., Chust, G., Santana del Pino, A., Polanco, J., and Castro, J. J. 2009. What drove tuna catches between 1525 and 1756 in southern Europe? – ICES Journal of Marine Science, 66: 1595–1604. From 1525 to 1756, catches of tuna in almadrabas (trapnets) fluctuated greatly, but the overall trend was a downwards one. The aim of this study is to assess the potential influence of climatic factors on tuna fishing. We performed time-series analysis of the climate over the years 1525–1756 and determined whether such events can be related to historical data on bluefin tuna catches in the almadrabas of Medina Sidonia. We used a generalized linear model to relate the tuna catches to climatic parameters. We carried out variance partitioning analysis of tuna catches to assess the relative contribution of climate from temporal autocorrelation. The temporal autocorrelation in tuna catches was used as a surrogate for the contribution of the population dynamics to variation in the catch series. The results indicated that climate accounted for up to 12.3% of the total variance, the temporal effects (autocorrelation) accounted for up to 38.8% of the total variance, and up to 35.7% of the catch was accounted for by the joint effect of the two components. The significant variance accounted for by climate suggests that low temperatures during the Maunder minimum (the so-called “The Little Ice Age”, years 1640–1715) may have reduced both recruitment and abundance of tuna in the North Atlantic and the Mediterranean. Our findings suggest that both environmental and population dynamic components played an important role in regulating the almadraba catches in Medina Sidonia.
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Craik, Clive. "Quantitative comparisons of moth-trap catches." Entomologist's Gazette 71, no. 1 (January 31, 2020): 1–16. http://dx.doi.org/10.31184/g00138894.711.1732.
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A simple method was used to compare the catches of seven different pairs of light-emitting moth-traps. Numbers of macro-moth individuals and species caught nightly by each member of a pair were recorded in comparisons that lasted between ten and 79 nights. A Robinson trap made significantly larger catches than a Skinner trap with an identical bulb, and a Robinson trap at ground level made significantly larger catches than an identical trap at a height of 90 cm. A 125 W MV bulb made significantly larger catches than an equivalent Wood's glass bulb or a multiple LED dome. No significant differences were found between a Robinson trap with a 125 W MV bulb and one with an 80 W MV bulb, or between two commercial brands of 125 W MV bulbs, or between two identical 125 W MV bulbs. This last comparison showed significant differences between the two sites used for these trials, apparently caused by a large flowering Buddleia at the more productive site. The findings suggest that catches may be maximised by using Robinson moth traps with 125 W MV bulbs, rather than the other traps or light sources tested here, and by placing them on the ground close to flowering Buddleia or other nectar-rich shrubs.
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Hasibuan, Siti Hawa, Alit Hindri Yani, and Nofrizal Nofrizal. "Composition of gillnet catches based on network size at UPT Fishery Port of Riau Province." South East Asian Marine Sciences Journal 1, no. 2 (March 15, 2024): 57–63. http://dx.doi.org/10.61761/seamas.1.2.57-63.
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Gill net catches are one of fishermen's dominant fishing gear at UPT Dumai City Fishing Port. Gill net catches are easy to operate, have a low price, and are durable. This research was conducted in July-August at UPT Port of Fisheries, Riau Province. This study aimed to determine differences in gill net catches based on different mesh sizes. The method used is the survey method. The catch of gill nets by type with a mesh size of 2 inches is 25 fish species. Based on the weight and number of individual fish, it was dominated by lomek (Harpodon sp), namely 1,359.5 kg or 21.5% and 16,314 individuals or 27.18%. The catch in the 3-inch mesh size was 23 species of fish. The percentage of catches based on weight dominated by senangin (Eleutheronema tetradactylum) was 30.38% (1,353.5 kg), and based on the number of individuals dominated by pomfret of 18.72% (4,534 individuals). The main catches in gill nets at UPT Dumai are lomek (Harpodon sp), senangin (Polynemus sp), pomfret (Bramidae sp) and machete (Chirocentrus sp). The primary and bycatch yields for the 2-inch mesh were 51.58% and 42.42%, while the 3-inch mesh sizes were 57.99% and 42.01%.
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Clegg, Thomas L., Edvin Fuglebakk, Kotaro Ono, Jon Helge Vølstad, and Kjell Nedreaas. "A simulation approach to assessing bias in a fisheries self-sampling programme." ICES Journal of Marine Science 79, no. 1 (December 5, 2021): 76–87. http://dx.doi.org/10.1093/icesjms/fsab242.
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Abstract The hierarchical structure and non-probabilistic sampling in fisher self-sampling programmes makes it difficult to evaluate biases in total catch estimates. While so, it is possible to evaluate bias in the reported component of catches, which can then be used to infer likely bias in total catches. We assessed bias in the reported component of catches for 18 species in the Barents Sea trawl and longline fisheries by simulating 2000 realizations of the Norwegian Reference Fleet sampling programme using the mandatory catch reporting system, then for each realization we estimated fleet-wide catches using simple design-based estimators and quantified bias. We then inserted variations (e.g. simple random and systematic sampling) at different levels of the sampling design (sampling frame, vessel, and operation) to identify important factors and trends affecting bias in reported catches. We found that whilst current sampling procedures for fishing operations were not biased, non-probabilistic vessel sampling resulted in bias for some species. However, we concluded this was typically within the bounds of expected variation from probabilistic sampling. Our results highlight the risk of applying these simple estimators to all species. We recommend that future estimates of total catches consider alternative estimators and more conservative estimates of uncertainty where necessary.
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Buras, Paweł, and Wiesław Wiśniewolski. "Numerical Model of Fish Exploitation – structure and application." Fisheries & Aquatic Life 27, no. 2 (June 1, 2019): 86–101. http://dx.doi.org/10.2478/aopf-2019-0010.
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Abstract Fisheries simulation models are tools used for forecasting the effects of exploitation and determining the directions of managing fisheries resources. The Numerical Model of Fish Exploitation (NMFE) and its capabilities were tested on a population of common bream, Abramis brama (L.) in a dam reservoir that is exploited by commercial and recreational fisheries. Based on the designated population parameters of N0, Fij, Mi, and ei and the size and structure of the common bream population in the reservoir, the model was used to examine hypothetical simulation variants of changes in fishing intensity E1 with nets and rods, changes in fishing intensity based on actual fishing effort with nets, changes in natural mortality, changes in the size of fish caught, and the impact of this on the size of the resources. Initial catches with nets and rods were calculated. Increasing fishing effort did not translate proportionally to increased catches, and the function was curvilinear. The results of simulations that reduced the intensity of fishing with nets and decreased catch sizes concurred with data from actual catches. Simulations of changes in natural mortality had various effects on the size of catches. Reducing parameter M did not impact the level of catches, while increasing parameter M reduced the size of catches significantly.
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Konopleva, Irina Victorovna. "Temporal variability of catches, distribution and dynamics of length of Russian sturgeon in waters of the Caspian Sea in 2015 –2020." Vestnik of Astrakhan State Technical University. Series: Fishing industry, no. 4 (December 30, 2021): 80–90. http://dx.doi.org/10.24143/2073-5529-2021-4-80-90.
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The paper presents long-term data on catches, distribution and length dynamics of Russian sturgeon in the waters of the Caspian Sea for the summer-autumn periods in 2015-2020. When considering the catches in the different parts of the sea there is found their annual variability, which is especially noticeable in the shallow zone in the North Caspian (0.31-2.0 specimens/trawl) and in the Middle Caspian (0-1.31 specimens/trawl). In the course of determining the reasons for the interannual dynamics of catches there were revealed several decadal rises. The dependence of decadal catches on the temperature of the bottom water layer was analyzed. The highest rise in catches was observed in the first decade of September when the temperature of water lowered up to 20.0-15.0 °C. The increase was observed due to migrating individuals to the shallow zone of the Northern Caspian Sea from shallow waters. Despite the variability of catches, the localization of Russian sturgeon schooling in the northern and middle part of the sea during the summer-autumn periods of 2015-2020 has certain similar features and trends. Sturgeon species fed mainly on shallow banks and deep dumps, where
the largest catches of sturgeon were recorded from 5.0 to 12.0 specimens/trawl. The absence of sturgeon at depths of up to 3.0 m isobath in the last five years is due to the water heating up to 27.6-28.8 °C. The decrease in the length of the Russian sturgeon observed in recent years is due to an increase in the proportion of youngsters (19.2-70.0%) against the background of a decrease in the adult population. It should be noted that from 2017 to 2019 there were not found the adult species in the catches by fishing nets, which indicates their continued re-moval from the population.
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Schubert, Aidan, Wanja Nyingi, Paul Tuda, Christopher M. Aura, Kevin Obiero, Julius Manyala, Ian G. Cowx, et al. "Reconstructing Kenya's total freshwater fisheries catches: 1950–2017." Marine and Freshwater Research 73, no. 1 (2022): 57. http://dx.doi.org/10.1071/mf21189.
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Most freshwater fisheries occur in developing countries, where freshwater fish underpin local food security and small-scale fisheries livelihoods. Comprehensive catch data are fundamental to support the sustainable management of freshwater fisheries. However, freshwater catch data reported by the Food and Agriculture Organization of the United Nations (FAO) on behalf of countries under-represent freshwater fisheries because they are dominated by fragmented and highly dispersed small-scale sectors, often with no designated landing sites. Kenya is an emerging economy with socioeconomically important freshwater fisheries and ongoing food security concerns. We undertook a reconstruction of freshwater fisheries catch data for Kenya for the period 1950–2017, aiming to improve the comprehensiveness of existing reported baseline data and to provide a more ecologically and spatially relevant time series dataset for research and management uses. We reconstructed catches for 16 major waterbodies in Kenya and found catches to be 32% higher than the data reported by the FAO on behalf of the country. The subsistence sector (small-scale, non-commercial, personal consumption) accounted for 71% of unreported catches, compared with 29% for artisanal sector catches (small-scale, commercial), suggesting that non-commercial catches for direct local consumption are substantially under-represented in nationally reported statistics and should receive greater attention to support sustainable food security in Kenya.
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de la Torriente, Ana, Renato A. Quiñones, Diego A. Miranda-Urbina, and Fidel Echevarría. "South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia." ICES Journal of Marine Science 67, no. 2 (October 16, 2009): 294–303. http://dx.doi.org/10.1093/icesjms/fsp235.
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Abstract de la Torriente, A., Quiñones, R. A., Miranda-Urbina, D. A., and Echevarría, F. 2010. South American sea lion and spiny dogfish predation on artisanal catches of southern hake in fjords of Chilean Patagonia. – ICES Journal of Marine Science, 67: 294–303. The South American sea lion (Otaria flavescens) is a pinniped known to interact with fisheries, potentially damaging gear and lowering catches. Predation by O. flavescens and spiny dogfish (Squalus acanthias) on artisanal southern hake (Merluccius australis) catches in fjords of Chilean Patagonia is estimated and compared. Observations were made in the Gulf of Ancud and Comau Fjord in southern Chile from October 2005 to September 2006. Losses of southern hake catches to O. flavescens predation were 1.6% of the total catch of the species, and to spiny dogfish predation were slightly higher, at 3.3%. The predation of both species on southern hake catches varied throughout the year, but was lower in summer. Both predators showed a preference for adult southern hake over juveniles. There was no significant relationship between predation on southern hake catches by the sea lion and the availability of adult and juvenile southern hake on longlines (AHCL). However, there was a significant relationship (p < 0.05) between AHCL and spiny dogfish predation. Most O. flavescens interaction events (81.4%) were during longline retrieval. Our results showed minimal interactions between O. flavescens and the artisanal southern hake fishery in the area, so with the present abundance of O. flavescens, there is no justification for reducing the sea lion population by hunting.
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Julianus, Notanubun, and Wilhelmina Patty. "PERBEDAAN PENGGUNAAN INTENSITAS CAHAYA LAMPU TERHADAP HASIL TANGKAPAN BAGAN APUNG DI PERAIRAN SELAT ROSENBERG KABUPATEN MALUKU TENGGARA KEPULAUAN KEI." JURNAL PERIKANAN DAN KELAUTAN TROPIS 6, no. 3 (April 30, 2010): 134. http://dx.doi.org/10.35800/jpkt.6.3.2010.157.
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One of potential fishing grounds for small pelagic fish in Southeast Mallucas Regency is Rosenberg Strait waters. In this region, a study on the effect of different light intensities of floating lift net on fish catches was carried out. The analyses were done on light distribution of 4 light intensities different: Petromaks Lamp and Underwater Lamps of each 18 watt, 36 watt and 54 watt. This study showed that catches of floating lift net using different light intensities were statistically significantly different. The use of 36 watt and 54 watt underwater lamp yielded the same amount of catches but higher than that of 18 watt-underwater lamp and petromaks, both in number and species. Catches consisted of 17 species, 16 fishs and 1 mollusca. Number of species and size also varied with light intensity used. There were 13 fishs species dominated by Stolephorus indicus as much as 46.9 kg or 22% for petromaks catches, 14 fishs species dominated by Rastrelliger kanagurata as much as 64 kg (31%) for 18 watt underwater lamp, 17 fishs species dominated by Rastrelliger kanagurata as much as 76 kg (28%) for 36 watt underwater lamp, and 15 fishs species dominated by Stolephorus devisi as much as 54.8 kg (22%) for 54 watt underwater lamp, respectively. Based on the results, it is recommended that the use of light intensity in fishing operations of floating lift net should be 36 watt and 54 watt underwater lamps, due to high catches, both in number and species. Beside that, since light fishing has also caught illegal fish size, number of this fishing gear type should be controlled.