CEFASc858a148-d272-44a1-a940-4acb924b3930 English dataset Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk pointOfContact 2023-12-07T05:44:55 EPSG Geodetic Parameter Registry 2022-01-07 revision WGS 84 Mixed demersal trawl catches in a trial of lights on the headline of a net in a Celtic Sea fishery in 2017 2023-09-19 publication 2023-12-07 revision 2023-07-17 creation CEFAS21698 https://data.cefas.co.uk Numbers and lengths of retained catch, and a sample of the discarded catch of select species of fish and cephalapod. Species specifically include haddock (Melanogrammus aeglefinus), grey gurnard (Eutrigla gurnardus), whiting (Merlangius merlangus), megrim (Lepidorhombus whiffiagonis) and Northern squid (Loligo forbesii). caught in the lower and upper codends of 22 parallel demersal fishing trawls equipped to explore the effect of artificial light on catches off southwest England during October and November 2017. Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk originator Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk custodian Centre for Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory (CEFAS) Cefas Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT UK data.manager@cefas.co.uk distributor European Commission info@publications.europa.eu owner notPlanned Fisheries SeaDataNet P03 parameter discovery vocabulary 2011-03-25 revision Fishing by-catch SeaDataNet P02 parameter discovery vocabulary 2011-03-25 revision Species distribution GEMET - INSPIRE themes, version 1.0 2008-06-01 publication Water column SeaVoX Vertical Co-ordinate Coverages 2010-05-18 revision Marine Environmental Data and Information Network MEDIN metadata record availability 2012-01-11 publication data.gov.uk MEDIN metadata record availability 2012-01-11 publication otherRestrictions noLimitations otherRestrictions An analysis of these data are published in Fisheries Research `https://www.sciencedirect.com/journal/fisheries-research`_ as Birch, S. F., S. D. Gregory, D. L. Maxwell, et al. (2023) How an Illuminated Headline Affects Catches and Species Separation in a Celtic Sea Mixed Demersal Trawl Fishery. Fisheries Research, 268, 106832. `https://doi.org/10.1016/j.fishres.2023.106832`_ .. _`https://www.sciencedirect.com/journal/fisheries-research`: https://www.sciencedirect.com/journal/fisheries-research .. _`https://doi.org/10.1016/j.fishres.2023.106832`: https://doi.org/10.1016/j.fishres.2023.106832 English biota -11.00 -4.50 49.00 52.00 2017-10-14 2017-11-04 Binary Delimited Geographic Information System Unknown https://data.cefas.co.uk/view/21698 Cefas Data Portal download The Cefas Data Portal contains metadata records and data sets available to download and connect to in support of our commitment to open science. Data is available in the following formats: Binary download, CSV, ESRI Shapefile. The data can also be accessed via the WFS and WMS protocols. dataset INSPIRE Data Specification on Species Distribution – Technical Guidelines 2013-12-10 publication false See the referenced specification Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 publication true See the referenced specification Sea trials were conducted in October and November 2017 aboard [a chartered fishing vessel] (14.98m overall length; 230hp). Three-wire, twin-rigged, trawls were towed in parallel. The treatment effect (lights) was introduced on one of the two trawls, while the other identical trawl served as a control, without the treatment effect. Bison double-vented size 8 doors, a 100kg clump weight, 18m splits and 110m of combination bridle were used to spread the rig. The trawls were constructed of green compact twine (160mm mesh size, 3mm diameter upper mouth; 115mm mesh size, 4mm diameter lower mouth, belly, and baitings; 90mm mesh size, 4mm diameter extension) and were rigged on groundgear made of 203mm rockhopper discs spaced at 355mm apart with chain droppers. To investigate the effect of lights on the vertical separation of different species, both trawls were fitted with a horizontal separator panel, constructed of green 4mm compact twine of 90mm mesh size. The separator panel was laced along the selvedge of each trawl, with a leading edge directly above the footrope, and let to two separate 80mm mesh size codends (also green 4mm compact twine). To minimise potential differences in catch efficiency between the two trawls, they were newly constructed for the purposes of the experiment, using identical materials. Also, at the start of the experiment the trawls were towed simultaneously for three hauls, without the inclusion of a treatment effect (lights), and the catches were compared. The catches from the two trawls were consistently comparable, providing confidence that they were fishing equally (data available on request from Data steward). To avoid any trawl-dependent effect on vertical separation, the lights were interchanged partway through the experiment between the two trawls. Fishing took place on the trawling grounds off the coast of southwest England (49.4935, -5.4025) in ICES sub-division 7.e. After each tow, the upper and lower codends of each trawl were emptied into 4 separate hoppers on the deck and the catch from each was sorted into retained and discarded components, then measured and recorded separately. Northern squid were measured to mantle length and all fish species (haddock, grey gurnard, whiting and megrim) were measured to total length (to the nearest cm below). All the fish retained for sale were measured. It was not practical for the two scientists to measure the length of every individual caught, so a known fraction of the substantially higher discarded portion of the catch was randomly sub-sampled to obtain length measurements. Within a haul, the absence of a species-specific catch-at-length within the range of lengths observed for that haul was recorded as a zero (0) catch. To investigate the effect of artificial lights on fish catches and on the vertical separation of catches, the headline of one of the two trawls fished simultaneously was equipped with blue LED lights (Centro Standard Power light, 464-468nm). These lights were chosen because they are inexpensive, use low levels of power to operate, are pressure-rated to water depths significantly greater than the study area, are robust enough to withstand the towing and hauling process and they are sensor-activated by contact with water. The longer wavelengths of blue and green light penetrate further in seawater, and consequently many fish have vision that is sensitive to these wavelengths (Solomon and Ahmed, 2016). Studies have shown that fish react to blue and green light stimulus (Marchesan et al., 2005), and while green light has been tested to modify behaviour in several fish directed fisheries (Grimaldo et al., 2018; Lomeli et al., 2018; O’Neill and Summerbell, 2019), blue light has been less studied (Cuende et al., 2022; Lomeli and Wakefield, 2019). A total of 56 lights were used to illuminate the headline of one trawl, spaced at 25cm apart and with the LEDs facing out from the center, towards the trawl wings. The experimental design assumed that the lights did not influence the catches and fish behaviour in the adjacent control trawl (in line with Melli et al., 2018; Lomeli et al., 2018; Karlsen et al., 2021). To preserve battery power, the lights were removed and deactivated after each deployment and a complete battery replacement was carried out mid-way through the experiment. References - Cuende, E., Herrmann, B., Sistiaga, M., Basterretxea, M., Edridge, A., Mackenzie, E.K., Kynoch, R.J., Diez, G., 2022. Species separation efficiency and effect of artificial lights with a horizonal grid in the Basque bottom trawl fishery. Ocean & Coastal Management 221, 106105. `https://doi.org/10.1016/j.ocecoaman.2022.106105`_ - Grimaldo, E., Sistiaga, M., Hermann, B., Larsen, R.B., Brinkoff, J., Tatone, I., 2018. Improving release efficiency of cod (Gadus morhua) and haddock (Melogrammus aeglefinus) in the Barents Sea demersal trawl fishery by stimulation escape behaviour. Canadian Journal of Fisheries and Aquatic Sciences 75, 402–416. `https://doi.org/10.1139/cjfas-2017-0002`_ - Karlsen, J. D., Melli, V., & Krag, L. A., 2021. Exploring new netting material for fishing: The low light level of a luminous netting negatively influences species separation in trawls. ICES Journal of Marine Science, 78, 2818–2829. `https://doi.org/10.1093/icesjms/fsab160`_ - Lomeli, M.J.M., Wakefield, W.W., 2019. The effect of artificial illumination on Chinook salmon behaviour and their escapement out of a midwater trawl bycatch reduction device. Fisheries Research 218, 112–119. `https://doi.org/10.1016/j.fishres.2019.04.013`_ - Lomeli, M.J.M., Wakefield, W.W., Herman, B., 2018. Illuminating the headrope of a selective flatfish trawl: Effect on catches of groundfishes, including pacific halibut. Marine and Coastal Fisheries: Dynamics, Management, and Ecosystem Science 10, 118–131. `https://doi.org/10.1002/mcf2.10003`_ - Marchesan, M., Spoto, M., Verginella, L., Ferrero, E.A., 2005. Behavioural effects of artificial light on fish species of commercial interest. Fisheries Research 73, 171–185. `https://doi.org/10.1016/j.fishres.2004.12.009`_ - Melli, V., Krag, L.A., Herrmann, B., Karlsen, J.D., 2018. Investigating fish behavioural responses to LED lights in trawls and potential applications for bycatch reduction in the Nephrops-directed fishery. ICES Journal of Marine Science 75, 1682–1692. `https://doi.org/10.1093/icesjms/fsy048`_ - O’Neill, F.G., Summerbell, K., 2019. The influence of continuous lines of light on the height at which fish enter demersal trawls. Fisheries Research 215, 131–142. `https://doi.org/10.1016/j.fishres.2019.03.010`_ - Solomon, O.O., Ahmed, O.O., 2016. Fishing with light: Ecological consequences for coastal habitats. International Journal of Fisheries and Aquatic Studies 4, 474–483. .. _`https://doi.org/10.1016/j.ocecoaman.2022.106105`: https://doi.org/10.1016/j.ocecoaman.2022.106105 .. _`https://doi.org/10.1139/cjfas-2017-0002`: https://doi.org/10.1139/cjfas-2017-0002 .. _`https://doi.org/10.1093/icesjms/fsab160`: https://doi.org/10.1093/icesjms/fsab160 .. _`https://doi.org/10.1016/j.fishres.2019.04.013`: https://doi.org/10.1016/j.fishres.2019.04.013 .. _`https://doi.org/10.1002/mcf2.10003`: https://doi.org/10.1002/mcf2.10003 .. _`https://doi.org/10.1016/j.fishres.2004.12.009`: https://doi.org/10.1016/j.fishres.2004.12.009 .. _`https://doi.org/10.1093/icesjms/fsy048`: https://doi.org/10.1093/icesjms/fsy048 .. _`https://doi.org/10.1016/j.fishres.2019.03.010`: https://doi.org/10.1016/j.fishres.2019.03.010 MEDIN 3.1.1