Alternative Rope Materials in Towed Fishing Gear to Reduce Plastic Waste, A Comparative Study of Mechanical Properties and Tolerance Against Wear and Tear

Source at https://www.proceedings.com/70833.html.This paper presents a comparative study assessing the wear tolerance of rope materials in demersal fisheries, specifically seine ropes and dolly ropes. Fourteen different rope materials were assessed in this study, including conventional and alternative commercially available synthetic polymers, and biodegradable materials including natural fibre ropes and custom-made polyester monofilaments. The sample materials were subjected to controlled wear from a rotating abrasive drum. Tensile testing was performed to determine and compare mechanical properties of the samples before and after exposure to wear. A wear tolerance coefficient has been suggested, i.e. a comparative unit between the different rope material samples and a standard blended polyester/polyethylene rope material as reference. The tested nylon ropes showed the lowest reduction in breaking strength post wear and thus the highest wear tolerance of all tested materials. Conventional and biodegradable polyester ropes and monofilaments also performed well compared to the standard reference rope. The performed tests did not only consider the effect of different raw materials, but the combined effect of material and structural properties. A rope’s tolerance to wear may be affected not only by the mechanical properties of the raw material, but also fibre thickness and cross section, and rope thickness, structure and lay of rope. This study demonstrated the potential of using biodegradable polymers with higher tolerance to wear than conventional non-degradable plastic materials as a circular solution to reduce microplastic pollution caused by demersal fisheries worldwide. Application of alternative commercially available ropes and hard-lay rope structures may increase the tolerance to wear and by that reduce plastic waste

The Coastal Reference Fleet 2007-2019 - Fleet composition, fishing effort and contributions to science

Catch quotas are used for the sustainable management of fish stocks and are based on official catch statistics and research surveysSustainable management of the Norwegian fisheries depends on quota advice that is based on stock assessments, using scientific data from research surveys and official landings statistics. The official landings statistics are given in metric tons, and for vessels less than 15 meters only include rough information on fishing effort. The research cruises, on the other hand, only take place in certain areas and at certain times of the year. However, these methods provide only partial information, as the official catch data at best include rough measures of effort, and the survey data are only collected at certain times of the year. In 2005, the Norwegian Coastal Reference Fleet (CRF) was established by the Institute of Marine Research (IMR) ,to obtain data at-sea on in order to register catches in numbers per species including size- and age composition, discards, and bycatch, as well as data on fishing , gear, and effort. The vessels in the CRF were selected along the entire coast using criteria to ensure that they as represent able for the Norwegian coastal fishing fleet as closely as possible. These historic data and the development of the CRF are evaluated have been ccomprehensively visualisedin , and this report, using descriptive methods and provides a description and visual displaysanalysis of the CRF data. Between 2007-2019, a total of 64 fishing vessels particip ated in the CRF along the Norwegian coast collecting data from a cumulated total number of 287 taxa, and from 29 137 individual fishing operations. The most common species was cod (Gadus morhua), which occurred in 60.9% of the fishing operations. Throughout the study period gillnet was the most common gear in all years, but there were small shifts in the gear composition over time of the CRF shifted, however gillnet was the most common gear in all years. Catch per unit effort (CPUE) from fisheries standardises catch data for comparisons in both space and time and is often used as a proxy indices of for fish abundance, assuming constant catchability (the probability from 0 to 1 of a fish being caught per unit effort) over time. When collecting fisheries dependent data, however, fishers actively try to maximise catchability of their target species or species composition, by e.g., using different gears to handle natural variations in catchability dependent on season, and area. Broad coverage in space and time may reduce this human bias as well as providing information on the behaviour of the fishers and the effect of technological advancements. This report includes CPUE timeseries for cod, haddock (Melanogrammus aeglefinus), and golden redfish (Sebastes norvegicus) north of 62°N.publishedVersio

A descriptive analysis of data from the Norwegian Coastal Reference Fleet and comparison with catch-per-unit-effort data from research surveys

Catch quotas are used for the sustainable management of fish stocks and are based on official catch statistics and research surveys. However, these methods provide only partial information, as the official catch data does, at best, include only rough measures of effort, and the survey data are only collected at certain times of the year. In 2005, the Norwegian Coastal Reference Fleet (CRF) was established by the Institute of Marine Research (IMR), in order to register catches per species including size- and age composition, discards, bycatch, gear, and effort as representable for the Norwegian coastal fishing fleet as possible. These data have not yet been comprehensively explored and visualised, and this thesis is a first attempt at making a general description of the CRF data. Between 2007-2019, a total of 64 fishing vessels participated in the CRF along the Norwegian coast collecting data on a cumulated 287 taxa from 29 137 individual fishing operations stratified by statistical areas. The most common species was cod (Gadus morhua), which occurred in 60.9% of the fishing operations. Throughout the study period, the gear composition of the CRF shifted in most areas along the coast, however gillnet was the most common gear in all years. Catch per unit effort (CPUE) standardises catch data for comparisons in both space and time and is often used as a proxy for abundance, assuming constant catchability. However, catchability varies with factors such as the target species, gear, season, and area. When collecting fishery independent data during the IMR’s Coastal Survey, the gear, locations, and timings are fixed between years to reduce variability in catchability. How the fishery dependent CPUE trends followed the survey trends for the selected species cod, haddock (Melanogrammus aeglefinus), and golden redfish (Sebastes norvegicus was therefore explored. When comparing mean annual CPUE from the CRF with the Coastal Survey index, the timeseries for cod followed each other closely over the entire study period and especially north of 67°N. The CPUE timeseries for haddock were less similar, and for golden redfish the two datasets showed very different trends. This is likely due to the imposed moratorium on this species from 2014. The results indicate that with large samples and over annual periods, the mean variability in the CRF catchability is evened out, however selective targeting and fishery restrictions make direct comparisons between fishery dependent and -independent data challenging. The CRF does, however, offer an insight into the nature of the fisheries, and together with surveys the two data sets complement each other to better understand the dynamics and impacts of a fishery

The Coastal Reference Fleet 2007-2019 - Fleet composition, fishing effort and contributions to science

Catch quotas are used for the sustainable management of fish stocks and are based on official catch statistics and research surveysSustainable management of the Norwegian fisheries depends on quota advice that is based on stock assessments, using scientific data from research surveys and official landings statistics. The official landings statistics are given in metric tons, and for vessels less than 15 meters only include rough information on fishing effort. The research cruises, on the other hand, only take place in certain areas and at certain times of the year. However, these methods provide only partial information, as the official catch data at best include rough measures of effort, and the survey data are only collected at certain times of the year. In 2005, the Norwegian Coastal Reference Fleet (CRF) was established by the Institute of Marine Research (IMR) ,to obtain data at-sea on in order to register catches in numbers per species including size- and age composition, discards, and bycatch, as well as data on fishing , gear, and effort. The vessels in the CRF were selected along the entire coast using criteria to ensure that they as represent able for the Norwegian coastal fishing fleet as closely as possible. These historic data and the development of the CRF are evaluated have been ccomprehensively visualisedin , and this report, using descriptive methods and provides a description and visual displaysanalysis of the CRF data. Between 2007-2019, a total of 64 fishing vessels particip ated in the CRF along the Norwegian coast collecting data from a cumulated total number of 287 taxa, and from 29 137 individual fishing operations. The most common species was cod (Gadus morhua), which occurred in 60.9% of the fishing operations. Throughout the study period gillnet was the most common gear in all years, but there were small shifts in the gear composition over time of the CRF shifted, however gillnet was the most common gear in all years. Catch per unit effort (CPUE) from fisheries standardises catch data for comparisons in both space and time and is often used as a proxy indices of for fish abundance, assuming constant catchability (the probability from 0 to 1 of a fish being caught per unit effort) over time. When collecting fisheries dependent data, however, fishers actively try to maximise catchability of their target species or species composition, by e.g., using different gears to handle natural variations in catchability dependent on season, and area. Broad coverage in space and time may reduce this human bias as well as providing information on the behaviour of the fishers and the effect of technological advancements. This report includes CPUE timeseries for cod, haddock (Melanogrammus aeglefinus), and golden redfish (Sebastes norvegicus) north of 62°N

Fersk linefanget brosme som råstoff til filetproduksjon - Lagringsstudie og tineforsøk

Brosme (brosme brosme) er en bunnlevende torskefisk som lever i Atlanterhavet, i vest langs Amerikas kyst og i øst langs Norgeskysten samt mellom Irland og Island. Brosme benyttes i dag hovedsakelig som råvare til produksjon av tørrfisk og saltfisk, men det er et mål om å øke verdiskapningen fra arten. Målet for studien har vært å dokumentere variasjon i kvalitet og holdbarhet for skinpakkede refresh-produkter av brosme gjennom en kjøleleagringsperiode på 12 dager. Alle parametere tatt i betraktning, inkludert evaluering av sensorisk og mikrobiell kvalitet, er en holdbarhetstid for refresh-produkter av brosmeloins på 12 dager oppnåelig. Riktig håndtering av råvarene, optimal og hygienisk prosessering, med rask innfrysing etter pakking, optimale prosedyrer for innfrysing og tining og riktig håndtering og lagring etter opptining, kan gi en helårsproduksjon av brosme, uten at det går på bekostning av kvaliteten til sluttproduktet.Fersk linefanget brosme som råstoff til filetproduksjon - Lagringsstudie og tineforsøkpublishedVersio

Reducing plastic pollution caused by demersal fisheries

Marine microplastics generated by wear and tear of bottom trawls and demersal seines during their service life is a growing environmental concern that requires immediate attention. In Norway, these fishing gears account for more than 70 % of the landings of demersal fish species, but they are also the leading sources of microplastics generated by fisheries. Because these two fishing gears are widely used around the world, replacing fossil-based non-degradable plastics with more abrasion-resistant materials, including biodegradable polymers, should contribute to the reduction of marine litter and its associated environmental impacts. However, the lack of available recycling techniques and the need for separate collection of biodegradable polymers means that these materials will most likely be incinerated for energy recovery, which is not favourable from a circular economy perspective. Nonetheless, from an environmental perspective the use of such biodegradable polymers in demersal fisheries could still be a better alternative to standard polymer materials