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Fisheries discards are an issue of general management and societal concern. This study presents the first analysis and characterization of discards composition from Iberian trawl fleets using Portuguese and Spanish onboard sampling programme data from 2004 to 2012. The allocation of observed trips into clusters with similar catch composition (landings and discards) is a useful procedure for the analysis of discarding levels of trips within each cluster and to understand the motives associated to those discard levels. In general, results indicate that Iberian discard rates are highly variable being low in some specific fisheries, but moderate to high in most trips. Although a high number of species is caught in these fisheries only few contribute to 95% of total weight of catch. The main discarding motives identified are related to market forces and regulations. This work shows that no one-fits-all solution exists to the minimization of discards in Iberian trawlers and discusses an array of possible discard mitigation measures, namely the implications of the recently proposed EU-wide discard ban.

Discard behavior in Spanish north Atlantic (ICES VIIIc,IXa) coastal fisheries concerning anglerfish species (Black anglerfish, L. budegassa and White anglerfish, Lophius piscatorius) is revisited herein. Results indicate that Angler discards basically depends on their length size. Year effect significantly conditioned discard behavior after 2000. Species differences in discard patterns were found also significant, being the less valuable white angler discarded at larger lengths than the black species. Diferent onboard sorting behavior indicates that fishers recognize angler species even at low length sizes, conditioning the degree of adoption of the assessment tools with regards to their relative market value.

An update of the yearly estimates of angler sh (black angler (Lophius budegassa) and white angler(Lophius piscatorius) discarded by the Spanish bottom trawl operating in the Northeast Atlantic ocean are presented. Black angler discards increased sharply in the last three year, while UShape with a maximum in 2010 is found for white angler. A 2003 - 2010 sampling methodology review has beeen carried out without detecting any shift in the protocol which could produce overestimation for recent years discards. Fishing covariates related to black angler discard data also indicates that shing practices remain stable along the series. We detect a steady increase in the species rst length of retention L50 from 21; 5cm in 2003 to a range 23cm - 25cm between 2004 - 2008 and 28cm since 2009. We conclude that interaction between the industry adoption of a Minimum Weigth Landing (500g) and the strength of recruitment indices explain the increase in amounts of angler discards.

Estimations of deep species discards from three Spanish bottom otter trawl m etiers operating in the Northeast Atlantic ICES V I, V II, V IIIc and North IXa are presented in this paper. Information has been ob- tained from the `Spanish Discard Sampling Programme' carried out by the IEO. Trip was the sampling unit, being raised to eet level using sh- ing e ort as auxiliary variable. Discard weigth estimates from time series of seven years (2003-2009) is presented for twelve species. Further, dis- card length distributions are presented for those species that have been observed whitin discarded fraction for more than three years. Estimates show high between-years variation in discard amounts, exceeding 35% CV in almost all cases. Results show that the largest amounts of discards of most of the species occur at depths less than 600m. Low market value is the main factor that forces the eet to discard most of deep species.

Herein we propose a nested boostrap scheme to explore di erent sources of variability in discard data. The proposed tool resamples on trips, hauls within trips and lengthclasess within hauls to include all sources of variability identified in the Spanish DCR sampling program scheme. Megrim (Lepidorhombus wiffiagonis) and Hake (Merluccius merluccius) discard data collected in 2008 from OTB-51 metier operating in ICES Division VI - VII, and Mediterranea DEF-Southern metier operating in the GSA 6S area were considered as case studies. Bootstrap Error and Coeficients of Variation associated to mean discards per trip were obtained and compared with asymptotic estimates. Furthermore, we use the bootstrap to quantify the contribution of the given sources of variability to global variability, and to assess simulated sampling scenarios differing each others in sampling effort. The last application of this method is for detecting outliers in 2008 sampled units (Trips). The good performance of the bootstrap method validates its use to obtain reliable error estimates in further regression and/or classiffication studies on discard data.

Estimates of Spanish bottom trawl discards of anglerfish Lophius budegassa and Lophius piscatorius 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.

Discards estimates from Spanish bottom otter trawl of anglerfish, Lophius budegassa (black anglerfish) and L. piscatorius (white anglerfish), in Northeast Atlantic Ocean (ICES Sub-areas VI, VII and Divisions VIIIabd) are presented in this paper. Information was obtained by observers on board in different discard programs carried out by Spanish Research Institutes. Total discards obtained by the different raising procedures were very similar and total discard raised by effort (number of trips) as a simple estimator was assumed as the adequate value. Values in weight range from 4 t to 590 t, and from 4 t to 320 t for white and black anglerfish respectively in Sub-areas VI and VII. Length distributions of discarded anglerfish (Sub-areas VI and VII) show that most of the specimens are juvenile individuals. Discards estimations show a high variability in weight and number along the period studied. Yearly abundance of juveniles in the area is a factor to understand the variability of discard quantities. This trend in Sub-areas VI and VII is reflected by similar pattern between juveniles (length < 31cm) discards estimations and recruitment indices (age 0) obtained by French (FR-EVHOES) for black anglerfish, and Irish (IR-IGFS) for white anglerfish. Inter-annual variation may also be explained by legal restriction on minimum weights (DCR) laid down in 2000 due to change in onboard sorting procedures.

A Spanish Discard Sampling Programme is being carried out in Divisions VIIIc and IXa North since 1993. The series provides information on discarded catch in weight and number and length distributions for Southem hake. Spanish sampling was used for years 1994, 1997, 1999- 2000 and 2003-2007. The number of trips sampled by the Spanish program was distributed by three trawl fleets: Baca otter trawl, Pair trawl and HVO trawl. Effort (trips number), hake landings and target species landings were the three variables tested to raise the Spanish discard, and the total effort by fleet gave the best results and hence it was used to estimate total discards. Hake discards for the Spanish fleet were estimated to vary between 240t (C.V. = 22.3) and 2 650t (C.V. = 24.3%). Estimated percentages of discarded hake in relation to total catch ranges between 9% and 31% in weight and 50% and X9% in number. As the Spanish estimated discard sampling is not based on yearly information, the relationships with Spanish survey (SP-GFS) abundance indices of age O was used to estimate discard abundanccs in those years were discard sampling was not performed. First ages (0, 1) were assumed to be discarded, and used in the estimates.