Eggers, Florian

Frandsen, Rikke

Krag, Ludvig Ahm

Madsen, Niels

Noack, Thomas

Today, extensive research is devoted to assess the effects of demersal trawling on the marine ecosystem, but only few of such studies considered the Danish seine. Danish seines and bottom trawls are grouped together in the legislation. Trawling is more common and responsible for the major part of the total landings where the seine fleet and catches are decreasing. The Danish seine is a specific type of encircling net to catch demersal fish. It is characterized by moderate fuel consumption and no use of heavy weights or doors, probably resulting in a relatively gentle bottom-contact and low interactions with theseabed compared to e.g. traditional trawling. However, the assumptions on the more environmental friendliness in seining are not sufficiently addressed.The present study aims at increasing the knowledge on Danish seining including its effect on the benthic ecosystem. The study starts with a comparison of existing catch data for Danish seines and trawls and continues with several substudies: Detailed description of all stages of the seining process to get a basis for the following investigations. Selectivity trials to support existing data, whereby both economically valuable and economically non-valuable species will be regarded Estimation of potential interactions of the gear with the sea bottomAssessment of survival chance of discarded animals Observation of fish behavior during capture process Combination of all single parts to provide an overall picture of effects of the Danish seine fishery on the marine environmentThis study may contribute to increase understanding the catching process in the seine fishery and the gears interaction with seabed during the different stages of the fishing process. The outcome of such studies will be highly relevant in future discussions on the impacts Danish seining may has on the marine environment and the faunal diversity and to maintain viable fisheries in the futur

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Downloaded from orbit.dtu.dk on: Dec 20, 2017Danish seine - An environmental friendly fishing method?Noack, Thomas; Eggers, Florian ; Frandsen, Rikke; Krag, Ludvig Ahm; Madsen, NielsPublication date:2014Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Noack, T., Eggers, F., Frandsen, R., Krag, L. A., & Madsen, N. (2014). Danish seine - An environmental friendlyfishing method?. Poster session presented at ICES Symposium 2014, Tromsø, Norway.Background  Although extensive research is devoted to assess the effects of demersal trawling on the marine ecosystem, only a handful of studies considered the Danish seine (ICES, 2010) – an encircling net to catch demersal fish (Sainsbury, 1996). By EU legislation, trawls and seines belong to one category and thus follow the same regulations, although there are differences between both gears, such as the lighter construction of seines and no use of heavy weights or doors. This results in a moderate fuel consumption of seines (Suuronen et al., 2012) and probably in relatively low interactions with the seabed. Furthermore, the fishing process is considered to be more gently which may increases the chance of discarded fish to survive (Revill, 2012). In total, the seine is regarded as a relatively ecofriendly fishing gear.          Since these statements are only based on a few scientific investigations and many assumptions, this study will test the environmental friendliness of Danish seines compared to trawls and – if necessary – try to improve its properties, e.g. selectivity and bottom impact. This will be done by an analysis of existing catch data (Danish observer program from 1997 to 2012; DOP) and following field trials.  First results Future tasks Thomas Noack1, Florian Eggers2, Rikke P. Frandsen1, Ludvig Ahm Krag1, Niels Madsen1    1 DTU Aqua, Technical University of Denmark, North Sea Science Park, 9850 Hirtshals, Denmark 2 Bramscher Str. 103, 49088 Osnabrück, Germany Contact - Danish seine -  An Environmental Friendly Fishing Method?  Thomas Noack  thno@aqua.dtu.dk +45 35 88 32 51 References EEC, 2012: Proposal for a Regulation of the European parliament and of the council on certain technical and control measures in the Skagerrak and amending Regulation (EC) No 850/98 and Regulation (EC) No 1342/2008. ICES, 2010: Report of the ICES - FAO Working Group on Fishing Technology & Fish Behaviour (WGFTFB). ICES CM 2010/SSGESST:14: 51-82. Revill, A. S. 2012: Survival of discarded fish, a rapid review of studies on discard survival rates. Sainsbury, J. C. 1996: Commercial fishing methods: an introduction to vessels and gears. Third edition. Commercial Fishing Methods: an Introduction To Vessels and Gears. Suuronen, P., Chopin, F., Glass, C., Løkkeborg, S., Matsushita, Y., Queirolo, D., Rihan, D. 2012: Low impact and fuel efficient fishing—Looking beyond the horizon. Fisheries Research, 119–120: 135-146.  Estimation of potential interactions of the gear with the sea bottom by using physical (e.g. Sidescan sonar) and biological methods (e.g. grab samples). 3. Benthic impacts (Start:2015) Detailed description of all stages of the seining process concerning geometry and forces by Dataloggers for depth, relative distance, tilt, speed, … 1. Process description (Start:2014) Observing behavior of fish during stages of the capture process with the aim to improve catch efficiency and selectivity of the gear. 5. Fish behavior (Start: ~2015) Experiments to support existing data by usage of codend cover and special collecting bags to estimate vertebrate species as well as invertebrate species.  2. Selectivity (Start:2014) Assessment of discarded fish´s chance to survive, which is important in terms of the future discard ban in European fisheries.  4. Discard Survival (Start:~2015) A first analysis of the DOP data (Fig. 2) shows that the diversity of catches in Danish seines (46 species) is lower than in trawls (78 species). The mean number of individuals per hour of species, targeted by Danish seiners, is slightly higher for Danish seines in most cases. However, the high standard deviations cause a high degree of uncertainty for most species. The high difference between the gears for Norway lobster is caused by the fact that it does not belong to the targets of Danish seiners, but it is one of the main targets of trawlers.        Seven species, caught by Danish seines are classified at least as “near threatened” by IUCN (International Union for Conservation of Nature). This list is extended by two species for trawl catches.     Figure 2: Catch comparison for Danish seine (N = 285) and trawls (N = 466). Data from DOP. Main targets of Danish seines highlighted in bold. Black dots indicate mean catch per hour, red bars indicate standard deviation and number on top shows number of hauls where this species occured. * indicates mention on list of future discard ban (EEC 2012). Letter combination shows conservation status after IUCN (NA = not assessed, LC = least concern, NT = near threatened, VU = vulnerable, EN = endangered, CR = critically endangered). 1 and 2 indicate reduction of catches by the factor of 10 or 20 due to very high catch rates.  Combination of all tasks to provide an overall picture of ecosystem effects of Danish seine fishing This project is financed by: Figure 1: Valid Hauls of DOP (nseine=285; ntrawl=466).        Danish seine stations.            Trawl stations.  

Danish seine - An environmental friendly fishing method?

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Danish seine - An environmental friendly fishing method?

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