Modelling trawling discards of the Alboran fisheries in the Mediterranean Sea

摘要: Abstract The ecosystem processes underlying the discard rates of demersal otter-trawl fishery in Alboran Sea, Western Mediterranean are investigated. We evaluate whether environmental and climatic variability, measured from operational oceanographic data, allow assessment discarded species abundances. Monthly data collected by onboard observers during 2011 2012 Northern Sea served as a case study trawling fishery’s dynamics. area was split into west east zones to account for differences Atlantic water influences, distinct geomorphology composition catches. Sixteen divided three groups were analysed: without discards, those partially completely discarded. Applying Gaussian Generalized Additive Models (GAM), we tested relationships standard products variability with These variables sea surface temperature (SST) chlorophyll (chl-a) satellite imagery, indicators conditions, North Oscillation index (NAO) indicator. applied target bycatch following species: gadoid like European hake (Merluccius merluccius), Blue Whiting (Micromesistius poutassou), Seabreams (Pagellus acarne, Pagellus erythrinus), Mackerels (Trachurus mediterraneus, Trachurus picturatus trachurus). Surface seawater relevant variable coastal eastern, more haline waters. Climatic represented NAO useful assessing productive western zone. Chlorophyll showed less relevance prediction models, but it related zones. Including patterns GAM models discards provides new perspective that may improve our predictive capabilities management decisions.