Journal articles on the topic 'Discarded fish'
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1
Wassenberg, TJ, and BJ Hill. "Partitioning of material discarded from Prawn Trawlers in Morton Bay." Marine and Freshwater Research 41, no. 1 (1990): 27. http://dx.doi.org/10.1071/mf9900027.
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Prawn trawlers in Moreton Bay, Queensland, discard about 3000 t of material each year. About 3% floats, and the rest sinks. The floating component is almost entirely fish. At night, floating discards are eaten by silver gulls (Larus novaehollandiae), crested terns (Sterna bergii) and, to a lesser extent, dolphins (Tursiops truncatus). There is little trawling during the day but the last discards are dumped overboard around dawn. At this time cormorants (Phalacrocorax varius) join the scavengers. Birds and dolphins scavenged only fish and cephalopods, and not crustaceans nor echinoderms. Birds are selective as to the size of fish they will eat, but most of the whole fish in the discards are below 50 g, and the largest fish that crested terns ate was 100 g. Dolphins are capable of taking the largest of the discarded fish. Most of the material that sinks is crustaceans (54%) and echinoderms (18%); the rest is elasmo- branchs and rubble. At night, about half of the fish that sink are eaten by diving birds and by dolphins. There was no indication of mid-water scavenging of sinking discards, except for cormorants and dolphins in the upper water column. Approximately 11% of the discards that reach the bottom comprise fish and crustaceans, which are eaten by crabs (Portunus pelagicus) and fish. The remainder- chiefly crabs, echinoderms and elasmobranchs-reach the bottom alive. Altogether, about 20% of discards are eaten by surface and bottom scavengers. Discards are probably important in maintaining populations of the major scavengers.
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Díaz, Paz, Juan Santos, Francisco Velasco, Alberto Serrano, and Nélida Pérez. "Anglerfish discard estimates and patterns in Spanish Northeast Atlantic trawl fisheries." ICES Journal of Marine Science 65, no. 7 (August 7, 2008): 1350–61. http://dx.doi.org/10.1093/icesjms/fsn127.
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Abstract Díaz, P., Santos, J., Velasco, F., Serrano, A., and Pérez, N. 2008. Anglerfish discard estimates and patterns in Spanish Northeast Atlantic trawl fisheries. – ICES Journal of Marine Science, 65: 1350–1361. Estimates of Spanish bottom trawl discards of anglerfish Lophius budegassa and Lophiuspiscatorius in the Northeast Atlantic Ocean are presented. Both species are commercially valuable in ICES Subareas VI and VII, and Divisions VIIIc and IXa. Information was obtained from observers on board during discard-monitoring programmes. Raising by effort, rather than by landings and target species, was used to determine the total annual discards by weight and number, the discard percentage, and the discard length distribution by stock throughout the dataseries. By weight and number, discards varied interannually, ranging from 4 to 600 t (∼28 000–7 000 000 fish) in northern stocks of anglerfish, and from 1 to 100 t (∼20 000–400 000 fish) in southern stocks. The discard percentage for both species and northern and southern stocks therefore ranged between 2 and 76% by number. Length distributions of the discarded anglerfish show that most were juveniles, although the pattern differed in years with high or with low rates of discarding. The number of juveniles caught apparently increased in most areas after 2000. Correlations between the quantities discarded and recruitment indices from French and Irish trawl surveys were found for northern stocks and with Spanish trawl survey indices for southern stocks.
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Borges, Lisa, Olvin A. van Keeken, Aloysius T. M. van Helmond, Bram Couperus, and Mark Dickey-Collas. "What do pelagic freezer-trawlers discard?" ICES Journal of Marine Science 65, no. 4 (April 3, 2008): 605–11. http://dx.doi.org/10.1093/icesjms/fsn050.
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Abstract Borges, L., van Keeken, O. A., van Helmond, A. T. M., Couperus, B., and Dickey-Collas, M. 2008. What do pelagic freezer-trawlers discard? – ICES Journal of Marine Science, 65: 605–611. Estimates of discards by the Dutch pelagic freezer-trawler fleet were derived based on data from observers on board commercial vessels. In all, 27 fishing trips of duration 2–5 weeks each were sampled between 2002 and 2005, covering the North Sea and the western waters of the British Isles. Different methods to estimate discards were compared, and raising these estimates by number of trips or by total landings did not greatly influence the annual estimates of total discards. Some 30 000 t of fish were discarded annually by the fleet, the commercial target species mackerel, herring, and horse mackerel being discarded most, with 41%, 19%, and 15% of the total discards by weight, respectively. The most commonly discarded non-commercial species was boarfish, accounting for 5% of total discards. Slippage accounts for 10% of all discards, and the most common species slipped is herring. There is extensive discarding of juvenile mackerel in the horse mackerel fishery, and to a lesser extent highgrading of mackerel in the same fishery.
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Davis, Michael W. "Key principles for understanding fish bycatch discard mortality." Canadian Journal of Fisheries and Aquatic Sciences 59, no. 11 (November 1, 2002): 1834–43. http://dx.doi.org/10.1139/f02-139.
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The mortality of discarded fish bycatch is an important issue in fisheries management and, because it is generally unmeasured, represents a large source of uncertainty in estimates of fishing mortality worldwide. Development of accurate measures of discard mortality requires fundamental knowledge, based on principles of bycatch stressor action, of why discarded fish die. To date, discard mortality studies in the field have focused on capture stressors. Recent laboratory discard experiments have demonstrated the significant role of environmental factors, size- and species-related sensitivity to stressors, and interactions of stressors, which increase mortality. In addition, delayed mortality was an important consideration in experimental design. The discard mortality problem is best addressed through a combination of laboratory investigation of classes of bycatch stressors to develop knowledge of key principles of bycatch stressor action and field experiments under realistic fishing conditions to verify our understanding and make predictions of discard mortality. This article makes the case for a broader ecological perspective on discard mortality that includes a suite of environmental and biological factors that may interact with capture stressors to increase stress and mortality.
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Uhlmann, Sebastian S., Aloysius T. M. van Helmond, Elísabet Kemp Stefánsdóttir, Sigríður Sigurðardóttir, John Haralabous, Jose Maria Bellido, A. Carbonell, et al. "Discarded fish in European waters: general patterns and contrasts." ICES Journal of Marine Science 71, no. 5 (April 14, 2013): 1235–45. http://dx.doi.org/10.1093/icesjms/fst030.
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Abstract To reduce the practice of discarding commercially fished organisms, several measures such as a discard ban and extra allowances on top of landings quotas (“catch quota”) have been proposed by the European Commission. However, for their development and successful implementation, an understanding of discard patterns on a European scale is needed. In this study, we present an inter-national synthesis of discard data collected on board commercial, towed-gear equipped vessels operating under six different national flags spanning from the Baltic to the Mediterranean Seas mainly between 2003 and 2008. We considered discarded species of commercial value such as Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), European hake (Merluccius merluccius), and European plaice (Pleuronectes platessa). Comparisons of discard per unit effort rates expressed as numbers per hour of fishing revealed that in the Mediterranean Sea minimum size-regulated species such as hake are generally discarded in much lower numbers than elsewhere. For most species examined, variability in discard rates across regions was greater than across fisheries, suggesting that a region-by-region approach to discard reduction would be more relevant. The high uncertainty in discard rate estimates suggests that current sampling regimes should be either expanded or complemented by other data sources, if they are to be used for setting catch quotas.
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Tsagarakis, K., A. Machias, M. Giannoulaki, S. Somarakis, and I. Karakassis. "Seasonal and temporal trends in metrics of fish community for otter-trawl discards in a Mediterranean ecosystem." ICES Journal of Marine Science 65, no. 4 (March 3, 2008): 539–50. http://dx.doi.org/10.1093/icesjms/fsn023.
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Abstract Tsagarakis, K., Machias, A., Giannoulaki, M., Somarakis, S., and Karakassis, I. 2008. Seasonal and temporal trends in metrics of fish community for otter-trawl discards in a Mediterranean ecosystem. – ICES Journal of Marine Science, 65: 539–550. Trends in discard to marketed ratios, size spectra, diversities, and trophic levels of the demersal fish community were examined using data from a seasonally closed commercial trawl fishery in the eastern Mediterranean Sea (Ionian Sea), over a period of about 10 years. Trends were also examined for the artificial fractions derived from the discarding process (the marketed, the discarded, and the non-marketed clusters of the catch), as well as for the “big” and “small” fractions (defined by the size at which 50% of all specimens were discarded). The ratio of the discarded/marketed catch fluctuated greatly. Two commercial (Merluccius merluccius, and Mullus barbatus) and two non-marketed species (Lepidotrigla cavillone, and Argentina sphyraena) were the characteristic species of the fractions. A declining trend with time was observed for the examined time-series for species richness (S), Margalef’s d, and average taxonomic distinctness (Δ+), whereas the variation in taxonomic distinctness (Λ+) increased. The composition and/or trophic level of discards in relation to the marketed catch seemed to be indicative of the exploitation state of the demersal community: differences between the discarded and marketed fractions were high at the beginning of the fishing season (autumn), but the values of the indices converged at the end of the fishing season (spring). These changes could be attributed to alternative discarding strategies for certain species in response to increased cumulative fishing mortality towards the end of the period.
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Catchpole, T. L., J. P. Feekings, N. Madsen, A. Palialexis, V. Vassilopoulou, J. Valeiras, T. Garcia, N. Nikolic, and M. J. Rochet. "Using inferred drivers of discarding behaviour to evaluate discard mitigation measures." ICES Journal of Marine Science 71, no. 5 (October 18, 2013): 1277–85. http://dx.doi.org/10.1093/icesjms/fst170.
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Abstract Discards refer to the part of the catch not retained on board during commercial fishing operations, but returned to the sea. The proposed European Union Common Fisheries Policy reform, to be implemented in 2014, sets out a gradual elimination of discards by reducing unwanted catches and ensuring that all catches are landed. To develop successful discard mitigation measures, it is necessary to identify the reasons for discarding. Here, we have developed a simple model that can be applied to data from observer programmes (ObsPs) to establish the contribution of different drivers of discarding behaviour. The analysis makes inferences on the causes of discarding by partitioning discards into four categories based on the length of the fish and the associated regulatory restrictions. The drivers are defined as: fish discarded below the legal minimum landing size; fish for which there is no market and that do not have a minimum landing size; fish for which there are inconsistencies in market and sorting practices; and discards that can be attributed to fishers' responses to quota restrictions. The approach is applied to data generated from ObsPs from five European Member States. All the inferred drivers contribute to the total discard quantity. Their relative contributions vary widely across countries, areas, gears, and species.
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Borges, Lisa, Alain F. Zuur, Emer Rogan, and Rick Officer. "Modelling discard ogives from Irish demersal fisheries." ICES Journal of Marine Science 63, no. 6 (January 1, 2006): 1086–95. http://dx.doi.org/10.1016/j.icesjms.2006.03.017.
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Abstract Annual discard ogives were estimated using generalized additive models (GAMs) for four demersal fish species: whiting, haddock, megrim, and plaice. The analysis was based on data collected on board commercial vessels and at Irish fishing ports from 1995 to 2003. For all species the most important factors influencing annual discard ogives were fleet (combination of gear, fishing ground, and targeted species), mean length of the catch and year, and, for megrim, also minimum landing size. The length at which fish are discarded has increased since 2000 for haddock, whiting, and plaice. In contrast, discarded length has decreased for megrim, accompanying a reduction in minimum landing size in 2000.
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Uhlmann, Sebastian S., Stijn M. Bierman, and Aloysius T. M. van Helmond. "A method of detecting patterns in mean lengths of samples of discarded fish, applied to the self-sampling programme of the Dutch bottom-trawl fishery." ICES Journal of Marine Science 68, no. 8 (June 8, 2011): 1712–18. http://dx.doi.org/10.1093/icesjms/fsr066.
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Abstract Uhlmann, S. S., Bierman, S. M., and van Helmond, A. T. M. 2011. A method of detecting patterns in mean lengths of samples of discarded fish, applied to the self-sampling programme of the Dutch bottom-trawl fishery. – ICES Journal of Marine Science, 68: 1712–1718. In 2009, a self-sampling programme was organized in the Netherlands, fishers sampling ca. 80 kg of discards from randomly selected bottom trawls in the North Sea. A statistical procedure is proposed to highlight samples, trips (with multiple samples), or vessels (which may have multiple trips within a year) where extreme mean lengths of discarded fish were observed. Randomization methods were used to test for evidence of non-randomness in patterns of highlighted discard samples, e.g. repeated observations of extreme mean lengths for consecutive discard samples across trips from the same vessel. European plaice (Pleuronectes platessa), common dab (Limanda limanda), grey gurnard (Eutrigla gurnardus), and whiting (Merlangius merlangus) were considered because these were the most abundant species in most of the discard samples. A linear mixed model was used to estimate random-sample effects on the estimated mean lengths by species. These random effects were incorporated into uni- and bivariate procedures to identify extreme samples that were summed for each vessel, and the probability of observing such numbers was estimated. Excluding these samples from the dataset had marginal effects on estimated size distributions of fish.
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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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Hill, BJ, and TJ Wassenberg. "Fate of discards from Prawn Trawlers in Torres Strait." Marine and Freshwater Research 41, no. 1 (1990): 53. http://dx.doi.org/10.1071/mf9900053.
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A study was made of the fate of teleosts, non-commercial crustaceans and cephalopods discarded from trawlers in Torres Strait. These groups make up about 80% of the discards by weight, have a high mortality rate and are therefore the most likely animals to be eaten by scavengers. The remaining 20% of discards consists of animals such as turtles, sharks, bivalves and sponges, which are caught in low numbers and appear to have a low mortality from trawling. Fish made up 78%, non-commerical crustaceans 18%, and cephalopods 3% by weight of the material studied. Nearly all fish were dead when discarded, and about half sank. About half of the non-commercial crustaceans were alive when discarded and all sank when discarded. Few cephalopods (2%) were alive when discarded, and around 75% sank. Sharks and dolphins were the most common scavengers of floating discards at night. Birds (common and crested terns, and lesser and greater frigates) scavenged only during the day. Discards that sank did so rapidly, taking less than 5 min to reach 25 m depth. A high rate of loss of baits set for 10 min in the water column (24% in trawled area at night) indicated significant scavenging in mid- water-probably by sharks. Observations of baits set on the bottom showed that teleosts (nemipterids) and sharks ate most of the material that reached the bottom; scavenging by invertebrates was negligible. In an adjacent area that had not been trawled for 8 years, no dolphins and fewer birds were seen scavenging floating discards but there were more sharks. In this area, significantly fewer fish were attracted to a bait on the bottom at night compared with the trawled area. The cause of the difference in scavenging observed between the two areas is not known; while it may reflect learned behaviour by some scavengers such as birds and dolphins, there may also be intrinsic differences between the two areas unrelated to trawling. Discarding from trawlers has the effect of transferring large quantities of biological material from the bottom to the surface. This makes available to surface scavengers food that would otherwise be inaccessible.
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TIRALONGO, FRANCESCO, EMANUELE MANCINI, DANIELE VENTURA, STEPHANIE DE MALERBE, FRANCESCO PALADINI DE MENDOZA, MASSIMILIANO SARDONE, ROBERTO ARCIPRETE, et al. "Commercial catches and discards composition in the central Tyrrhenian Sea: a multispecies quantitative and qualitative analysis from shallow and deep bottom trawling." Mediterranean Marine Science 22, no. 3 (September 10, 2021): 521. http://dx.doi.org/10.12681/mms.25753.
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In the Mediterranean Sea, the catch of bottom trawl fisheries is composed of a complex mix of fish and invertebrates with a considerable amount of discards. Seasonal composition of catches and discards of bottom trawls operating at different depths in the central Tyrrhenian Sea were investigated from October 2014 to October 2015. The mean total catch per unit effort (CPUE) ranged between 30.93±8.43 and 27.52±9.88 kg/h in shallow and deep fishing grounds, respectively. The discarded fraction of the catch was 39.9 % in shallow and 43.3% in deep fishing grounds. The mean CPUE of commercial target species were similar in shallow and deep trawling (10.81+5.82 vs 8.92±3.16 kg/h). The commercial bycatch was lower in shallow (6.66±1.25 kg/h) than in deep grounds (8.24±2.91 kg/h), whilst the discards were lower in deep (10.43±5.14 kg/h) than shallow grounds (13.43±5.29 kg/h). Overall, 246 species were caught during fishing operations, out of which 209 were included in discards. The number of species recorded in shallow grounds (199 caught species with 166 discarded) was higher than that recorded in deep grounds (116 caught species with 102 discarded). Fish were the most represented taxa in the shallow discards, followed by echinoderms; crustaceans, and were the main discarded taxa in deep water. Depth was the main factor affecting both commercial catches and discards composition, whereas the season affected the CPUE of main target species only. The results confirmed that discards were higher in shallow than in deep trawling, suggesting that the latter is more efficient than the former in catching fishery resources for human consumption. Understanding the factors that affect discarding is the starting point for adopting management measures to mitigate negative impacts of trawl fisheries on marine resources and benthic communities.
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Vázquez, José Antonio, Ana I. Durán, Araceli Menduíña, Margarita Nogueira, Ana María Gomes, Joana Antunes, Ana Cristina Freitas, Esther Dagá, Paula Dagá, and Jesus Valcarcel. "Bioconversion of Fish Discards through the Production of Lactic Acid Bacteria and Metabolites: Sustainable Application of Fish Peptones in Nutritive Fermentation Media." Foods 9, no. 9 (September 4, 2020): 1239. http://dx.doi.org/10.3390/foods9091239.
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In the current work, we study the capacity of 30 peptones obtained by enzyme proteolysis of ten discarded fish species (hake, megrim, red scorpionfish, pouting, mackerel, gurnard, blue whiting, Atlantic horse mackerel, grenadier, and boarfish) to support the growth and metabolite production of four lactic acid bacteria (LAB) of probiotic and technological importance. Batch fermentations of Lactobacillus plantarum, L. brevis, L. casei, and Leuconostoc mesenteroides in most of the media formulated with fish peptones (87% of the cases) led to similar growths (quantified as dry-weight biomass and viable cells) and metabolites (mainly lactic acid) than in commercial control broth (MRS). Comparisons among cultures were performed by means of the parameters obtained from the mathematical fittings of experimental kinetics to the logistic equation. Modelling among experimental and predicted data from each bioproduction was generally accurate. A simple economic assessment demonstrated the profitability achieved when MRS is substituted by media formulated with fish discards: a 3–4-fold reduction of costs for LAB biomass, viable cells formation, and lactic and acetic acid production. Thus, these fish peptones are promising alternatives to the expensive commercial peptones as well as a possible solution to valorize discarded fish biomasses and by-products.
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Kennelly, S. J., S. C. Drew, and C. D. Delano Gagnon. "Rates of retained and discarded catches from demersal fish trawling off the north-eastern United States." Marine and Freshwater Research 48, no. 3 (1997): 185. http://dx.doi.org/10.1071/mf96099.
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The retained- and discarded-catch rates of fish, crustaceans and molluscs caught by demersal fish trawlers were quantified in a large-scale observer survey of fleets working off the north-eastern United States. The data presented come from catches sampled from 7757 tows on 1010 fishing trips during the four-year period from July 1990 to June 1994 and are summarized as the weights retained and discarded (per hour of trawling) for many of the important commercial and recreational species in the region. Problems with the spatial and temporal design of the programme restricted statistical analyses of the data and prevented summaries across all statistical areas and months. However, separate summaries for individual areas (over all months) and individual months (over all areas) identified several spatial and temporal patterns in retained- and discarded-catch rates for individual species and combinations of species. Noticeable increases and decreases in catch rates during the four-year period provided information on the relative health of certain stocks, and overall discard percentages indicated relative selectivities of the trawling operations sampled.
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Sturludottir, Erla. "Exploring the effects of discarding using the Atlantis ecosystem model for Icelandic waters." Scientia Marina 82, S1 (December 20, 2018): 51. http://dx.doi.org/10.3989/scimar.04736.09a.
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Discarding fish has been a part of the fisheries for centuries but it has been very difficult to monitor how much is discarded, especially in areas where it is an illegal activity. In this study the ecological and economic effects of discarding were investigated using the Atlantis model for Icelandic waters. Five different scenarios were compared, using different discarding rates and selectivities. The results showed that a complete stop of discarding fish (cod and haddock) and landing everything instead had little ecological and economic impact. Improved selectivity, which would result in not catching the fish that would be discarded, had great beneficial economic effects. The increase in biomass led to higher landings, which consequently led to higher revenue. Also, the cost decreased with increasing biomass, which increased the profit of the fisheries. None of the five scenarios had great ecological effects but only discarding of cod and haddock, which have low discard rates, were considered in this study.
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Stratoudakis, Yorgos, Robert J. Fryer, and Robin M. Cook. "Discarding practices for commercial gadoids in the North Sea." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 7 (July 1, 1998): 1632–44. http://dx.doi.org/10.1139/f98-029.
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Understanding fishers' discarding behaviour, and anticipating their reactions to changes in the biological or regulatory characteristics of a fishery, are important for dealing with the problem of discarding. In this paper, we investigate the discarding of haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and Atlantic cod (Gadus morhua) in the North Sea, using data collected by scientific observers onboard Scottish demersal vessels. We describe discarding on each trip by species-specific discard curves and explore how these curves depend on biological and regulatory variables. There are large differences in the size of discarded fish between inshore and offshore areas, with offshore-operating vessels discarding larger fish (high-grading). Increases in legal landing size correspond to immediate increases in the size of discarded fish, particularly for haddock and cod in inshore areas. In general, discarding practices for haddock and cod are similar over time and consistent across gears, whereas decisions for the lesser valued whiting are more variable and can be affected by the catch composition.
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DAMALAS, DIMITRIOS, ALESSANDRO LIGAS, KONSTANTINOS TSAGARAKIS, VASSILIKI VASSILOPOULOU, KONSTANTINOS I. STERGIOU, ARGYRIOS KALLIANIOTIS, MARIO SBRANA, and FRANCESC MAYNOU. "The “discard problem” in Mediterranean fisheries, in the face of the European Union landing obligation: the case of bottom trawl fishery and implications for management." Mediterranean Marine Science 19, no. 3 (August 29, 2018): 459. http://dx.doi.org/10.12681/mms.14195.
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Since the first introduction of the landing obligation (a.k.a. Discard ban) in 2015, the EU Mediterranean fisheries are facing some unforeseen challenges. The demersal bottom trawl fisheries, being the most significant contributors to the so-called 'discard problem', are confronted with the greatest challenges. Data from the Italian and the Greek fleet, spanning over two decades (1995–2015), were analysed with the intention of revealing the diversity and heterogeneity of the discard problem, especially for regulated species. Species composition of discards, as well as discarding rates, were shown to be irregular, fluctuating among areas, depth strata, seasons and years. Although fish dominated the discarded gross catch in weight, benthic invertebrates (other than commercial cephalopods and crustaceans) were the taxa discarded almost exclusively. The established minimum conservation reference size was largely ignored by fishers. From a management point of view, the present investigation suggests that the recently established Discard Management Plans lack scientific evidence (given the high intrinsic variability of the parameters and confusion regarding the rules) and provide exemptions from the landing obligation that will in practice allow the average Mediterranean bottom trawl vessel to continue business as usual. Moreover, detecting if these rules are actually respected is an almost impossible task for the Mediterranean control and enforcement authorities. Incentivizing the adoption of fishing technologies and practices that reduce pre-harvest mortality and post-harvest discards, while avoiding damage to sensitive marine species and habitats, seems the only way to move forward, rather than dealing with the problem after it has occurred.
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MILISENDA, G., S. VITALE, D. MASSI, M. ENEA, V. GANCITANO, G. B. GIUSTO, C. BADALUCCO, M. GRISTINA, G. GAROFALO, and F. FIORENTINO. "Discard composition associated with the deep water rose shrimp fisheries (Parapenaeus longirostris, Lucas 1846) in the south-central Mediterranean Sea." Mediterranean Marine Science 18, no. 1 (February 13, 2017): 53. http://dx.doi.org/10.12681/mms.1787.
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Discarding in fisheries is believed to be a waste of natural resources, as it is the part of the total catch brought on board but then returned to the sea dead or alive for any reason. This study aims to advance knowledge of the discards associated with the deep water rose shrimp fisheries in the south-central Mediterranean Sea. We address this issue by examining the data collected within the module of commercial catch monitoring (Campbiol) of European data collection framework (DCF) between January 2009 and December 2013. Multivariate data analysis and the generalized additive model (GAMs) were used to assess the spatio-temporal composition of the discard and factors influencing its distribution. Overall, discard represented 32.9±15.4% of the total catch. Multiple analysis of variance highlighted the significant effect on discard assemblage only for the factor of depth (p-value <0.05). In general, bony fish were the most discarded organisms (23.5±14.4%). Cartilaginous fish, crustaceans and other invertebrates represented approximately 13% of the total catch. The fraction of discard in the catch presented significant variation regarding the years, depth and fishing ground. Our results showed that most of the discards in the deep water rose shrimp (DPS) fisheries are due to species that have a minimum legal size (Hake, DPS, Trachurus spp.), and are consequently subjected to the discard ban (art. 15 of the reg. EU 1380/2013). To avoid the landing of discards, specific measures aimed to minimize the unwanted catches of undersized species should be implemented.
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Erzini, Karim, Pedro Monteiro, Artur Araújo, and Margarida Castro. "Limited mid-water scavenging of trawl discards." Journal of the Marine Biological Association of the United Kingdom 83, no. 4 (August 2003): 731–34. http://dx.doi.org/10.1017/s0025315403007719h.
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The consumption or scavenging of fish in the water column at depths from 75 to 275 m in Algarve (southern Portugal) trawl fishing grounds was evaluated. Longlines were used to suspend baits throughout the water column while electric fishing reels were used to simulate sinking discards. Eighteen species were caught, with higher catch rates near the surface than near the bottom. However, scavenging rates were generally highest near the bottom and lowest in the middle of the water column. At depths less than 100 m the majority or all the fish were scavenged throughout the water column, while at depths greater than 200 m most of the fish were untouched after periods of time greater than would be required for them to sink to the bottom. Since other studies have shown that most small fish discards are scavenged at the surface by sea birds and most of the discarded species that sink are either too large or not attractive to pelagic predators, these results suggest that mid-water scavenging of trawl discards in deep water is relatively unimportant.
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Neat, F. C., M. Breen, R. M. Cook, I. M. Gibb, and P. J. Wright. "Electronic tags reveal behaviour of captured and discarded fish." Journal of Fish Biology 74, no. 3 (February 2009): 715–21. http://dx.doi.org/10.1111/j.1095-8649.2008.02159.x.
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Fernández-Arias, Mónica, Iago Álvarez-Olcina, Pablo Malvido-Fresnillo, José Antonio Vázquez, Mohamed Boutinguiza, Rafael Comesaña, and Juan Pou. "Biogenic Calcium Phosphate from Fish Discards and By-Products." Applied Sciences 11, no. 8 (April 9, 2021): 3387. http://dx.doi.org/10.3390/app11083387.
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Every year, millions of tons of fish waste are generated from fishing activities, and a similar amount is discarded and returned to the sea as unwanted catches. This material can be used as a biological source for many potential new added-value products, such asobtaining hyaluronic acid from fish eyeballs or extracting collagen from fish skin, but there are not many utilities for fish bones yet. This work tackles the transformation of fish discards into calcium phosphates. Discards from scorpionfish (Scorpaena scrofa) and Atlantic horse mackerel (Trachurus trachurus), as well as by-products generated from aquaculture activities (heads and trimmings frames) of salmon (Salmon salar), were used to obtain calcium phosphate. Biphasic carbonated hydroxyapatite (HA) /beta-tricalcium phosphate (TCP) material was obtained. The biphasic HA-TCP material has a promising range of applications in the biomedical field based on its similarity to calcium phosphates found in human bones in terms of crystallite size and carbonate content. The presence of Na, Mg, Sr, and K ions in the HA-TCP material is very beneficial, since they contribute to bone metabolism and cell adhesion.
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Ramadan, Fauzan, Farhan Ramdhani, Deni Efizon, and Nofrizal Nofrizal. "Ancaman keanekaragaman hayati (Biodiversity) terhadap ekosistem daerah penangkapan pukat hela." Dinamika Lingkungan Indonesia 7, no. 2 (July 30, 2020): 129. http://dx.doi.org/10.31258/dli.7.2.p.129-136.
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Trawl has the size a mesh size a small size pockets of the cod end. This allows the trawl fishing gear to potentially be a fishing gear that is not selective about the size of the fish and the species that are targeted for its catch. If this fishing gear is left, its existence will eventually have a negative impact on the sustainability of fish resources, especially in coastal waters. The purpose of this study is to calculate the composition and proportion of main catches, bycatch and discarded catches. It is expected that knowing the composition and proportion of the main, by-product and discarded catches can provide an overview of the pressure on stocks and sustainability of fisheries resources in the waters where trawl is operated. The method used in this study is a survey method. A series of survey activities were carried out directly in the field to identify and count the types of species caught by trawlers. Based on the percentage of main catch, by-catch and discard per type, it Matuta planipes are the dominant species caught by trawlers (23.65%). The main catch Parapenaeus longirostris 15.92%. In addition, the main catch caught were Parapenaeopsis sculptilis (9.787%), Penaeus merguiensis (0.646%), Metapenaeus brevicornis (10.118%), Penaeus indicus (0.029%) and Squilla mantis (0.153%). Percentage of bycatch reaches 2.245% of 10 species caught and discarded catches reach 61.103% of 25 species caught.
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Benoît, Hugues P., Sébastien Plante, Molly Kroiz, and Thomas Hurlbut. "A comparative analysis of marine fish species susceptibilities to discard mortality: effects of environmental factors, individual traits, and phylogeny." ICES Journal of Marine Science 70, no. 1 (August 14, 2012): 99–113. http://dx.doi.org/10.1093/icesjms/fss132.
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Abstract Benoît, H. P., Plante, S., Kroiz, M., and Hurlbut, T. 2013. A comparative analysis of marine fish species susceptibilities to discard mortality: effects of environmental factors, individual traits, and phylogeny. – ICES Journal of Marine Science, 70:99–113. Determining the sustainability of fishing mortality for discards requires information on discard amounts as well as capture and release mortality rates. Formal estimates of these rates are costly and only available for a limited number of species and fisheries. In their absence, proxies for discard mortality could inform risk assessments of fishing mortality sustainability for discarded species. Here, time-to-mortality (TM) was assessed for 48 marine fish species exposed to air following capture during an annual multi-species bottom-trawl survey. Species-specific estimates of TM were related qualitatively to more formal estimates of discard mortality from commercial fisheries, confirming the use of TM as a proxy. The effects on TM of species and individual traits, phylogenetic similarity (proxy for traits not explicitly included in the analysis) and environmental factors related to capture were also assessed. Much of the observed individual variability was explained by intraspecific and interspecific positive relationships between body size and TM. Sedentary species and those lacking a gas bladder or deciduous scales had greater TM. Effects of phylogeny and capture depth and temperature were also found. This study demonstrates how reliable proxies of discard mortality rate can be readily obtained in the field or estimated from relevant covariates.
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Macdonald, P., I. R. Cleasby, C. H. Angus, and C. T. Marshall. "The contribution of quota to the discards problem: a case study on the complexity of common megrim Lepidorhombus whiffiagonis discarding in the northern North Sea." ICES Journal of Marine Science 71, no. 5 (February 9, 2014): 1256–65. http://dx.doi.org/10.1093/icesjms/fsu009.
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Abstract The common megrim Lepidorhombus whiffiagonis is a commercially important, high-value flatfish species. From the early 2000s, discarding of common megrim in the northern North Sea has been widespread. In this study, we investigated temporal variation in megrim discarding in the mixed demersal fishery in the northern North Sea before, and following recent quota increases. Furthermore, logistic regression models were applied to investigate the effects of a range of explanatory factors on the probability of individual fish being discarded. Results indicate that discarding on the vessels sampled has declined from an average of 54% of the total common megrim catch in 2009 to 20% in 2012. The decrease in total discards was primarily a result of a decrease in the proportions of discards categorized by the crew as small within the catches from 0.39 (±0.02 s.e.) in 2009 to 0.10 (±0.01 s.e.) in 2012. Model outputs also suggest that the likelihood of a fish being discarded decreases significantly (p < 0.001) with increasing quota. The current megrim total allowable catch serves only to regulate landings and does little to regulate fishing mortality. Additionally, the proposed reform of the CFP, including the move towards a discards ban and the implementation of maximum sustainable yield, raises a number of concerns that need to be addressed if the northern North Sea mixed demersal fishery is to be managed sustainably and remain economically viable in the future.
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Stratoudakis, Y. "Fish discarded from Scottish demersal vessels: Estimators of total discards and annual estimates for targeted gadoids." ICES Journal of Marine Science 56, no. 5 (October 1999): 592–605. http://dx.doi.org/10.1006/jmsc.1999.0500.
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Rudershausen, P. J., J. A. Buckel, and J. E. Hightower. "Estimating reef fish discard mortality using surface and bottom tagging: effects of hook injury and barotrauma." Canadian Journal of Fisheries and Aquatic Sciences 71, no. 4 (April 2014): 514–20. http://dx.doi.org/10.1139/cjfas-2013-0337.
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We estimated survival rates of discarded black sea bass (Centropristis striata) in various release conditions using tag–recapture data. Fish were captured with traps and hook and line from waters 29–34 m deep off coastal North Carolina, USA, marked with internal anchor tags, and observed for release condition. Fish tagged on the bottom using SCUBA served as a control group. Relative return rates for trap-caught fish released at the surface versus bottom provided an estimated survival rate of 0.87 (95% credible interval 0.67–1.18) for surface-released fish. Adjusted for results from the underwater tagging experiment, fish with evidence of external barotrauma had a median survival rate of 0.91 (0.69–1.26) compared with 0.36 (0.17–0.67) for fish with hook trauma and 0.16 (0.08–0.30) for floating or presumably dead fish. Applying these condition-specific estimates of survival to non-tagging fishery data, we estimated a discard survival rate of 0.81 (0.62–1.11) for 11 hook and line data sets from waters 20–35 m deep and 0.86 (0.67–1.17) for 10 trap data sets from waters 11–29 m deep. The tag-return approach using a control group with no fishery-associated trauma represents a method to accurately estimate absolute discard survival of physoclistous reef species.
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Church, Gabriella E., Robert W. Furness, Glen Tyler, Lucy Gilbert, and Stephen C. Votier. "Change in the North Sea ecosystem from the 1970s to the 2010s: great skua diets reflect changing forage fish, seabirds, and fisheries." ICES Journal of Marine Science 76, no. 4 (December 10, 2018): 925–37. http://dx.doi.org/10.1093/icesjms/fsy165.
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Abstract Understanding anthropogenic impacts are crucial to maintain marine ecosystem health. The North Sea has changed in recent decades, largely due to commercial fishing and climate change. Seabirds can act as useful indicators of these changes. By analyzing n = 20 013 pellets and n = 24 993 otoliths regurgitated by great skuas Stercorarius skua in northern Scotland over five decades from the 1970s to the 2010s (in 36 years 1973–2017), we reveal how the diet of this top predator has changed alongside the changing North Sea ecosystem. Sandeels Ammodytes spp. were the most common dietary item during the 1970s, but became virtually absent from the 1980s onward. Discarded whitefish dominated skua diets from the 1980s to the present day, despite long-term declines in North Sea discard production. However, the discarded fish eaten by great skuas has become smaller and the species composition changed. Skua pellets only rarely contained avian prey in the 1970s but this increased during the 1980s, and fluctuated between 10% and 20% from the 1990s to 2010s. There have also been changes in the avian prey in the diet—black-legged kittiwakes Rissa tridactyla generally being replaced by auks Alcid spp. and northern fulmars Fulmarus glacialis. The Shetland marine ecosystem has experienced steep declines in sandeel stocks and in seabirds that feed on them. Great skuas have been able to prey switch to respond to this change, supported by abundant discards, enabling them to maintain a favourable population status while other seabird species have declined.
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Garthe, Stefan, and Birgit Scherp. "Utilization of discards and offal from commercial fisheries by seabirds in the Baltic Sea." ICES Journal of Marine Science 60, no. 5 (January 1, 2003): 980–89. http://dx.doi.org/10.1016/s1054-3139(03)00099-7.
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Abstract The distribution and abundance of scavenging seabirds and their utilization of discards and offal between June and December 1998 were studied in the western Baltic Sea. Herring gulls were clearly the most numerous scavenging species in all areas and all seasons, followed by great black-backed gulls, lesser black-backed gulls and mew gulls. High percentages of discarded gadoids (cod, whiting), clupeids (herring, sprat), scad, rockling and offal were consumed by seabirds during experimental discarding on fishing boats, whereas the percentages of flatfish consumed were extremely low. There was a clear effect of cod length on total and species-specific consumption by birds but this pattern was hardly evident for clupeids or dab. By combining official discard and offal statistics and our experimental discarding, we estimate that 6500 t of fish discards and 16 000 t of offal were consumed annually by seabirds in the Baltic Sea. Bivalves, especially blue mussels Mytilus edulis, were the most frequently represented food item in herring gull pellets. Fish identified in the pellets consisted mainly of gadoids, in particular cod. The proportion of discards in herring gull pellets was on average 1.6% (range: 0–4.5%) at Laboe and 17.5% at Warnemünde (range: 9.4–25.5%), but pellets bias diet assessment as offal and other soft prey (including clupeids) will be under-represented. Scavenging on discards and offal is a widespread phenomenon in the Baltic Sea as it is in other shelf areas of Europe, but the number of bird species involved is generally lower and strongly biased towards gulls, especially herring gulls.
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Coppola, Daniela, Chiara Lauritano, Fortunato Palma Esposito, Gennaro Riccio, Carmen Rizzo, and Donatella de Pascale. "Fish Waste: From Problem to Valuable Resource." Marine Drugs 19, no. 2 (February 19, 2021): 116. http://dx.doi.org/10.3390/md19020116.
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Following the growth of the global population and the subsequent rapid increase in urbanization and industrialization, the fisheries and aquaculture production has seen a massive increase driven mainly by the development of fishing technologies. Accordingly, a remarkable increase in the amount of fish waste has been produced around the world; it has been estimated that about two-thirds of the total amount of fish is discarded as waste, creating huge economic and environmental concerns. For this reason, the disposal and recycling of these wastes has become a key issue to be resolved. With the growing attention of the circular economy, the exploitation of underused or discarded marine material can represent a sustainable strategy for the realization of a circular bioeconomy, with the production of materials with high added value. In this study, we underline the enormous role that fish waste can have in the socio-economic sector. This review presents the different compounds with high commercial value obtained by fish byproducts, including collagen, enzymes, and bioactive peptides, and lists their possible applications in different fields.
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Vázquez, José Antonio, Ana Durán, Margarita Nogueira, Araceli Menduíña, Joana Antunes, Ana Cristina Freitas, and Ana María Gomes. "Production of Marine Probiotic Bacteria in a Cost-Effective Marine Media Based on Peptones Obtained from Discarded Fish By-Products." Microorganisms 8, no. 8 (July 26, 2020): 1121. http://dx.doi.org/10.3390/microorganisms8081121.
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The industrial production of marine bacteria with probiotic properties is limited by the excessive cost of the culture media adequate for their growth. The present work aimed to study the suitability of 30 marine media formulated with nitrogen sources (fish peptones) from different fish discards and seawater, for the growth of two marine probiotic bacteria (MPB), namely Phaeobacter sp. and Pseudomonas fluorescens. These fish peptones were produced from several discarded fish and by-products (heads, skins, and whole individuals of megrim, mackerel, gurnard, hake, etc.). In all cultivations, no significant differences were found on cell viability when the microorganism grew on commercial or alternative media. In relation to the biomass production, the growth of Phaeobacter sp. on waste media was commonly similar or a 20% lower than observed in the control cultures. For P. fluorescens, various peptones (skin peptones of pouting and blue whiting) showed even higher productive ability than commercial peptones. An initial economical evaluation revealed that low-cost media reduced until 120 times the cost of production of MPB.
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Broadhurst, MK, and SJ Kennelly. "Effects of an increase in mesh size on the catches of fish trawls off New South Wales, Australia." Marine and Freshwater Research 46, no. 4 (1995): 745. http://dx.doi.org/10.1071/mf9950745.
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In response to claims that fish trawls off New South Wales, Australia, caught excessive quantities of under-size fish, the catches of finfish by a conventional fish trawl (constructed of 90-mm mesh in the body) were compared with those by a fish trawl constructed of 100-mm mesh in the body. Catches by the 100-mm trawl showed a 27% reduction in all by-catch and a 28% reduction in the numbers of retained tiger flathead, compared with catches by the conventional trawl. The 100-mm trawl also showed a 48% and 47% reduction in the numbers and weights respectively of discarded tiger flathead and a 57% and 63% reduction in the numbers and weights respectively of discarded rubberlip morwong. For john dory, however, at a particular locality where large numbers occurred, the 100-mm trawl caught significantly more fish than did the conventional trawl (a mean increase in weight of 66%). There is a need to determine species-specific mesh selectivities and to study the behaviour of fish in trawls. The importance of the results for the future management and operational efficiency of trawl fisheries is discussed.
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Barnes, Thomas C., Steven G. Candy, Stephen Morris, and Daniel D. Johnson. "Understanding discarding in trawl fisheries: A model based demersal case study with implications for mitigating and assessing impacts." PLOS ONE 17, no. 2 (February 17, 2022): e0264055. http://dx.doi.org/10.1371/journal.pone.0264055.
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Despite research and public scrutiny over recent decades, discarding continues to be an issue for trawl fisheries. Previous research demonstrates that environmental, biological, operational, legislative and socioeconomic drivers affect a fisher’s decision to discard an organism. Therefore, the reduction of fishery discards requires a better understanding of fishery-specific drivers. Despite considerable research and mitigation, further work is required to reduce discarding to acceptable levels (currently ~ 50% in Australia). To better understand the drivers of discarding, this study used a modelling approach to determine environmental and operational factors that drive discarding in the New South Wales (NSW) ocean prawn trawl fishery (OPT). Further, the study investigated the relationship between the discarded number of individuals from all functional species groups (i.e. elasmobranchs, crustaceans and fish combined) and the retained catch weight. This model was also run on just fish partly due to their disproportionally high contribution to the discard assemblage (e.g. 76% of all species or higher taxon) and importance (e.g. to the ecosystem and fisheries). The results quantified relationships of environmental and operational drivers of discarding and the relationship of fish discarding and retained catch weight was found to be linear. However, the identified relationships appear complicated and, whilst an important first step, more work is required to identify all drivers influencing discarding practices. We, in combination with previous research, suggest implementation of effort quotas may be a suitable management initiative to reduce discarding and its impact; at least whilst more research is conducted to better understand this complex process. Furthering our understanding of discarding is urgent given its global impact and the rate of discarding in the OPT.
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García-Moreno, Pedro J., Irineu Batista, Carla Pires, Narcisa M. Bandarra, F. Javier Espejo-Carpio, Antonio Guadix, and Emilia M. Guadix. "Antioxidant activity of protein hydrolysates obtained from discarded Mediterranean fish species." Food Research International 65 (November 2014): 469–76. http://dx.doi.org/10.1016/j.foodres.2014.03.061.
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Wilson, S. K., S. Street, and T. Sato. "Discarded queen conch (Strombus gigas) shells as shelter sites for fish." Marine Biology 147, no. 1 (January 26, 2005): 179–88. http://dx.doi.org/10.1007/s00227-005-1556-2.
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Madsen, Niels, Rasmus Ern, and Aage Kristian Olsen Alstrup. "Estimating Discard Mortality in Commercial Fisheries without Fish Dying: A 3R Challenge." Animals 12, no. 6 (March 19, 2022): 782. http://dx.doi.org/10.3390/ani12060782.
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Globally, it is estimated that around 10% of the fish that are caught are discarded. This is considered to be a wasteful human marine activity since these fish are often dead or dying. To reduce the high discard rates of commercial fisheries, the European Union (E.U.) has enacted a landing obligation that includes the ability to exempt “species for which scientific evidence demonstrates high survival rates”. Therefore, discard survival studies (henceforth DSSs) have become one of the most politically prioritized fisheries research areas in European fisheries. International expert groups have produced guidance reports to promote best practices and to harmonize the methodologies. Nevertheless, there has not been any focus on how to implement animal welfare (AW) regulations experimentally. Discard survival studies are “frontrunners” in fisheries science research areas that are embedded by animal research welfare requirements and are expected to be more restrictive in the future because of an increased public focus on fish welfare. This paper focuses on AW regulations in relation to conducting DSSs, but the outreach is much broader. We investigate experimental procedures by bringing in relevant examples, using output results, and relating this information to relevant AW guidelines and regulations by focusing on implementing 3R principles.
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Knight, Carey T., Richard T. Kraus, Demetra A. Panos, Ann Marie Gorman, Benjamin S. Leonhardt, Jason Robinson, and Michael Thomas. "Is Barotrauma an Important Factor in the Discard Mortality of Yellow Perch?" Journal of Fish and Wildlife Management 10, no. 1 (December 1, 2018): 69–78. http://dx.doi.org/10.3996/062018-jfwm-056.
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Abstract In physoclistous fishes, barotrauma caused by rapid decompression during capture may be an important source of fishing mortality that is unquantified for some fisheries. We developed a predictive logistic model for barotrauma incidence in Yellow Perch Perca flavescens and applied this model to Ohio's recreational and commercial fisheries in Lake Erie where fisheries managers implicitly consider discard mortality to be negligible in current stock assessment. As expected, capture depth explained most of the variation in incidence, with comparatively small effects of season, sex, and size categories. Measurements of whole body and gonad density provided limited explanation for the categorical effects. Both fisheries spanned a range of depths (7.6 to 16.8 m) that corresponded to a broad range of barotrauma incidence (13 to 74%). Using a recent example, we estimated that additional fishing mortality due to barotrauma in discards was approximately six-fold higher in the commercial than recreational fishery. Overall, this additional mortality was <1% of lake-wide population size estimates. Thus, the assumption that all discarded Yellow Perch survive is unlikely to result in a detectable bias in population estimates. One caveat is that we still do not understand how strong year-classes might influence discard mortality via increased discard rate and barotrauma incidence for small fish.
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Madhu, Devarapaga, Bhaskar Singh, and Yogesh C. Sharma. "Studies on application of fish waste for synthesis of high quality biodiesel." RSC Adv. 4, no. 59 (2014): 31462–68. http://dx.doi.org/10.1039/c4ra03590a.
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Kabir, S. M. Fijul, Taslim Ur Rashid, and Ioan I. Negulescu. "Gelation of Textile Dye Solution Treated with Fish Scales." Gels 5, no. 3 (July 18, 2019): 37. http://dx.doi.org/10.3390/gels5030037.
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In the present article, the commercial value of fish scales (FS), one of the most discarded fish wastes, has been identified by discovering their gelation capability. Fish scales of different physical forms were applied for the removal of dyes (acid red 1 (AR1), acid blue 45 (AB45), and acid yellow 127 (AY127)) from textile dye solution by absorption process. An astounding phenomenon, gelation of the treated solution, was noticed when it was aged for a certain period. The absorption of dye by FS was confirmed and quantified by FT-IR and UV-visible spectroscopy analyses, respectively. Process optimization revealed that pristine FS showed better gelation efficacy compared to pulverized FS. The gelation process was successful only when the dye solution contained acid and salt. As most of the textile effluents contain acids and salts in the discarded dye solution, this gelation process implies an obvious indication of the saving process and chemical cost in textile waste treatment. The jellified wastewater was characterized by exploring the rheological properties. Based on these analyses, potential application areas have been discussed.
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PYZ-ŁUKASIK, RENATA, KRZYSZTOF SZKUCIK, WALDEMAR PASZKIEWICZ, and ŁUKASZ DROZD. "Results of sanitary-veterinary examination of fish in Poland in 2010–2016." Medycyna Weterynaryjna 74, no. 1 (2018): 6028–2018. http://dx.doi.org/10.21521/mw.6028.
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Fish and other fishery products are subjected to the official sanitary-veterinary controls as required by Regulation (EC) No 854/2004. The aim of the study was to analyse the results of sanitary-veterinary examinations of fish in Poland in 2010–2016 conducted by the Veterinary Inspection. The results of the laboratory examination on fish were worked out based on the annual reports issued by the General Veterinary Inspectorate. The analysis of the results included the sanitary-veterinary examination of marine and farmed fish (salmonids, cyprinids and other fish species) carried out by the Veterinary Inspection. Moreover, the sanitary evaluation of samples of fish, seafood and their products on the basis of microbiological, chemical and sensory analysis results performed by the State Sanitary Inspection (PIS) were used. Throughout the analyzed period, a total of 1436109009.60 kg of fish were examined, in that 145711.71 kg (0.01%) were declared unfit for human consumption. The most important reasons for fish rejection proved to be parasite invasions (45.91% of the total amount of discarded fish), viral diseases (41.74%), bacterial diseases (9.71%) and the exceeded acceptable level of histamine (2.56%) and dioxins (0.07%). The sanitary examination of the food samples carried out by the PIS showed that the causes of rejection included the surpassed levels of food additives (2.3–2.7% of all the discarded samples) and chemical contaminants (1.4–2.4%) as well as abnormal microbiological and sensory tests results (0.1–1.2%). Summing up, the amount of fish rejected during the analyzed period was low which indicates the good quality of the obtained raw material..
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Damalas, Dimitrios, Christos D. Maravelias, Giacomo C. Osio, Francesc Maynou, Mario Sbrana, Paolo Sartor, and John Casey. "Historical discarding in Mediterranean fisheries: a fishers' perception." ICES Journal of Marine Science 72, no. 9 (August 12, 2015): 2600–2608. http://dx.doi.org/10.1093/icesjms/fsv141.
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Abstract Discarding of commercially important fish species in the bottom trawl fisheries in the northern Mediterranean Sea was investigated by soliciting the long-term recollections of fishers engaged or formerly engaged in such fisheries. The main aim of our investigation was to describe the prevalence of discarding and its evolution over the past 70 years using information gathered through individual questionnaire-based interviews with fishers from ports in Spain, Italy, and Greece, following a standardized sampling protocol. Although it proved impossible to derive absolute estimates of the volume of discarded catches over the period investigated, we conclude that over the past 70 years, discarding as a practice has gradually increased in the northern Mediterranean trawl fisheries and has been accompanied by a shift in the species composition of the discarded catch. While discarding can occur for a number of reasons, our investigations indicate that discarding in the past was mostly driven by market demand, but recent legal and regulatory constraints have led to changes in fishing strategies and became a significant reason for discards.
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Biswas, Amal, Yuta Takahashi, Kota Isaka, Fumiaki Takakuwa, Hideki Tanaka, and Kenji Takii. "Total Replacement of Fish Meal by the Combination of Fish Residue Meal and Soy Protein from Soymilk in the Diet of Red Sea Bream (Pagrus major)." Animals 12, no. 23 (November 29, 2022): 3351. http://dx.doi.org/10.3390/ani12233351.
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Three experiments were performed to explore (i) the complete replacement of fish meal (FM) with a combination of fish residue meal (FRM, 65% round discarded fish + 35% byproduct), soy protein concentrate (SPC) from soymilk and corn gluten meal (CGM) in Trial 1 and (ii) the utilization of diets composed of increasing byproducts in FRM in the summer (Trial 2) and winter (Trial 3) seasons. In Trial 1, the ratio of (SPC + CGM):FM in the control diet (C) was 8:2. The FM component from diet C was replaced with FRM (diet, RM20), where the ratio of (SPC + CGM):FRM became 8:2, and this ratio was changed to 6:4, 4:6 and 2:8, and referred to as RM40, RM60 and RM80, respectively. In Trials 2 and 3, the ratios of round discarded fish and byproducts in FRM were adjusted to 65:35 (FRM1), 30:70 (FRM2) and 0:100 (FRM3), and the FRM component from diet RM40 in Trial 1 was replaced with FRM1, FRM2 and FRM3 to formulate diets RM1, RM2 and RM3, respectively. In Trials 1, 2 and 3, rearing periods were 10, 8 and 12 weeks, respectively. In Trials 1 and 3, there were no significant differences in growth parameters, nutrient retention efficiency or plasma constituents among the treatments, irrespective of the inclusion levels of FRM in the diets (p > 0.05). Although there were no significant differences in final mean weight (p > 0.05), daily feeding rate and feed conversion ratio in diet RM3 were significantly higher and lower, respectively, compared to the control group in Trial 2 (p < 0.05). These results suggest that FM can be entirely replaced with FRM, and that the total elimination of round discarded fish from FRM does not affect growth or health status in red sea bream either in summer or winter seasons.
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Reyes, María, María Rodríguez, Juan Montes, Fernando G. Barroso, Dmitri Fabrikov, Elvira Morote, and María José Sánchez-Muros. "Nutritional and Growth Effect of Insect Meal Inclusion on Seabass (Dicentrarchuss labrax) Feeds." Fishes 5, no. 2 (June 1, 2020): 16. http://dx.doi.org/10.3390/fishes5020016.
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Abajo: se repite los tres en el resumen. This work studies the effect of high-level fish meal replacement with insect meal: YW meal (obtained from Tenebrio larvae fed a broiler diet), BSF meal (from hermetia larvae fed broilers diet), BSFm meal (obtained from hermetia larvae fed discard fish) on growth performance nutritive indices and in vitro digestibility of Dicentrarchus labrax juvenile. Three different insect meals were used: BSF meal from hermetia larvae fed broilers diet; BSF improve (BSFm) obtained from hermetia larvae fed discarded fish; YW meal obtained from the larvae of Tenebrio fed a broiler diet. Five diets were used, a control (C) diet and four experimental diets by replacing fishmeal with insect meal from BSF at 30% and 50% (BSF30 and BSF50) substitutions, BSFm at 50% substitution (BSF50 m) and YM at 50% substitution (YW50). Nutritional and growth indices worsened by including insect meal, especially for hermetia meal at 50% substitution, BSF50 and BSF50 m. The internal organs’ weight reflected the growth of the fish fed each experimental diet. No differences were found in fillet composition. Nevertheless, under our experimental condition, YW replacement obtained better results than both BSF diets.
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Hudson, A. V., and R. W. Furness. "Utilization of discarded fish by scavenging seabirds behind whitefish trawlers in Shetland." Journal of Zoology 215, no. 1 (May 1988): 151–66. http://dx.doi.org/10.1111/j.1469-7998.1988.tb04890.x.
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García-de-Vinuesa, Alfredo, Montserrat Demestre, Arnau Carreño, and Josep Lloret. "The Bioactive Potential of Trawl Discard: Case Study from a Crinoid Bed Off Blanes (North-Western Mediterranean)." Marine Drugs 19, no. 2 (February 2, 2021): 83. http://dx.doi.org/10.3390/md19020083.
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Although knowledge of the bioactive compounds produced by species inhabiting coastal waters is increasing, little is known about the bioactive potential produced by marine species occupying deeper habitats with high biodiversity and productivity. Here, we investigate about the bioactive potential of molecules produced by species that inhabit the crinoid beds, a poorly known essential fish habitat affected by trawling, wherein large amounts of commercial and noncommercial species are discarded. Based on a trawl survey conducted in 2019, 14% of the 64 species discarded on crinoid beds produce molecules with some type of bioactive potential, including; soft corals (Alcyonium palmatum); tunicates (Ascidia mentula); bony fish, such as horse mackerel (Trachurus trachurus); European hake (Merluccius merluccius); and chondrichthyans, such as small-spotted catshark (Scyliorhinus canicula). In addition, 16% of the discarded species had congeneric species that produce compounds with bioactive potential, indicating that such species might also possess similar types of bioactive molecules. Molecules with antioxidant, antitumour, antihypertensive, and antibacterial properties were the most frequent, which could provide the basis for future research aiming to discover new marine-based drugs and compounds for other human uses. Among all species or genera that produce compounds with bioactive potential, 68% presented medium or high vulnerability to trawling. Results show that the discarded catch contains many species, which produce different bioactive compounds that represent an added-value resource. These results highlight the importance of manage properly crinoid beds, to ensure that species that produce molecules with bioactive potential inhabiting these habitats are protected.
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Kalogirou, Stefanos, Charalampos Dimitriadis, Christos D. Maravelias, Dimitrios Poursanidis, Mihalis Margaritis, Helen Miliou, and Leif Pihl. "Bycatch Dynamics from a Small-Scale Shrimp Trap Fishery in the Mediterranean Sea." Diversity 14, no. 4 (April 12, 2022): 292. http://dx.doi.org/10.3390/d14040292.
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Small-scale fisheries (SSFs) in the Mediterranean and Black seas play a significant social and economic role, representing 84% of the fishing fleet (70,000 vessels), 26% of total revenue (USD 633 million) and 60% of total employment (150,000 people), with the Food and Agriculture Organization (FAO) recently taking important initiatives to sustain livelihoods. Effective management of important natural fisheries resources that sustain livelihoods requires a holistic approach accounting for all parts of the catch. Quantitative data on seasonal catch dynamics together with classification of bycatch species to IUCN vulnerability status and associated revenues from retained incidental catch were used to reveal the effect of a small-scale shrimp trap fishery on bycatch. We use three main quantitative variables (i.e., density, biomass and number of bycatch species) and show a positive correlation between bycatch and the seasonal catch dynamics of the target species during late spring and summer. On the contrary, discards were proportionally lower during winter, with the majority of discarded fish species not considered endangered. Six retained species in spring–summer and five discarded species in winter were found to modulate the structure of species’ assemblage. Out of 55 bycatch species, 26 were retained and 29 discarded. Only four species were considered threatened, all of which were caught in very low numbers (<2 individuals), while the majority of the retained species was not considered endangered. The rapid sorting time (<1 min/per trap) pointed towards a decreased effect on certain discarded crustacean species and a significant reduction in total bycatch with timely haul time (from 71 to 47%). The results of this study can be used when considering future mitigation measures for this fishery, while the methodology used can provide insights into the management of similar trap fisheries worldwide when taking into account the sustainability of SSFs and the regional vulnerability status of bycatch species.
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SUÁREZ, MARÍA DOLORES, MARÍA ISABEL SÁEZ, MIGUEL ÁNGEL RINCÓN-CERVERA, LUIS HIDALGO, and JOSE LUIS GUIL-GUERRERO. "Discarded fish on the Spanish Mediterranean coast: influence of season on fatty acids profiles." Mediterranean Marine Science 22, no. 2 (March 31, 2021): 232. http://dx.doi.org/10.12681/mms.24909.
Full textAbstract:
This work focused on determining the fatty acid (FA) composition of commonly discarded fish on the Spanish Mediterranean coast in winter and summer to assess their potential use as raw sources of very long-chain polyunsaturated fatty acids (VLCPUFAs). Total n-3 VLCPUFA content significantly varies depending on capture season, and values were higher in winter for Pomadasys incisus (1.36 g/100 g), Chelidonichthys lucerna (1.67 g/100 g) and Trachinus draco (2.04 g/100 g), while Pagellus acarne had larger n-3 PUFA amounts in summer (3.89 g/100 g). Generally for most species, monounsaturated FA, eicosapentaenoic acid (20:5n-3) and total FA had higher values in summer, while both the n-3 VLCPUFA fraction and DHA content were higher in winter. Knowledge of these changes allows the processes for their proper use as valuable PUFA sources to be adjusted. The discarded fish herein studied could be generally considered to be raw n-3 VLCPUFAs sources.
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Kennelly, Steven J., and Charles A. Gray. "Reducing the mortality of discarded undersize sand whiting Sillago ciliata in an estuarine seine fishery." Marine and Freshwater Research 51, no. 8 (2000): 749. http://dx.doi.org/10.1071/mf00014.
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A field experiment was done to determine the effects of mesh size in the bunt and codend of an estuarine beach-seine net on the meshing (gilling) and discarding of undersize sand whiting Sillago ciliata (Sillaginidae). Four mesh sizes were examined: 45 mm, 50 mm, 57 mm and 64 mm, in an alternate-haul experiment in the Clarence River, New South Wales, Australia. A laboratory experiment was also done to determine the mortality of sand whiting after becoming meshed in seine nets. The currently allowed mesh size (50 mm) catches a large proportion of undersize sand whiting that become meshed in the netting and are subsequently discarded. The laboratory experiment showed that ~40% of these fish may die within a few weeks whereas no unmeshed fish die. In contrast, the 57 mm mesh size meshed few undersize sand whiting yet retained almost the same number of legal-sized fish as the 50 mm mesh. Hence, the maximum mesh size allowed in the bunts of nets used in this fishery should be raised to 57 mm to allow the escape of large numbers of undersize sand whiting that are currently being caught, meshed and discarded in a condition that leads to significant mortality.
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Lin, Cherng-Yuan, and Rong-Ji Li. "Engine performance and emission characteristics of marine fish-oil biodiesel produced from the discarded parts of marine fish." Fuel Processing Technology 90, no. 7-8 (July 2009): 883–88. http://dx.doi.org/10.1016/j.fuproc.2009.04.009.
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Thompson, Michael E., and Wilfred A. Côté. "Potential effects of discarded trition paperboard six-pack carriers on fish and wildlife." Marine Pollution Bulletin 34, no. 2 (February 1997): 135–37. http://dx.doi.org/10.1016/s0025-326x(96)00128-2.
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Blanco, M., F. Domínguez-Timón, R. I. Pérez-Martín, J. Fraguas, P. Ramos-Ariza, J. A. Vázquez, A. J. Borderías, and H. M. Moreno. "Valorization of recurrently discarded fish species in trawler fisheries in North-West Spain." Journal of Food Science and Technology 55, no. 11 (September 3, 2018): 4477–84. http://dx.doi.org/10.1007/s13197-018-3376-7.
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