Projected effects of ocean warming on an iconic pelagic fish and its fishery.

Increasing sea temperature is a driver of change for many fish traits, particularly for fast-growing epipelagic species with short life spans. With warming, altered spawning phenology and faster growth may produce substantially larger body sizes of the new cohort, affecting fishery productivity. We present an individual-based model (IBM) that predicts the distribution of fish length at catch under observed and projected thermal scenarios, accounting for mortality, temperature-dependent spawning phenology, temperature- and photoperiod- dependent growth. This IBM was demonstrated with Coryphaena hippurus (common dolphinfish), a circumglobally-distributed and highly thermophilic species sustaining commercial and recreational fisheries where it is present. The model projected a 13.2% increase in the average length at catch under marine heatwave conditions compared to the current thermal regime (1995-2005 average). Projections under RCP scenarios 4.5 and 8.5 by the end of the century led to 5.1% and 12.8% increase in average length, respectively. Furthermore, these thermal scenarios affected spawning phenology differently, producing higher variance in body size under RCP 8.5 scenario with respect to marine heatwave conditions. This study highlights how the environmental effects of climate change can alter the distribution of species length at catch.

PAHs, pesticides, personal care products and plastic additives in plastic debris from Spanish Mediterranean beaches.

In this study the role of plastic debris as a pollution vector has been evaluated by determining the concentrations of hydrophobic organic contaminants in polymers from three Western Mediterranean coastal areas as well as their potential transfer to seawater. Plastic debris was sampled at three Iberian Peninsula Southeastern beaches, each affected by different predominant anthropogenic activities (tourism, agriculture, urban activities, transport and industry). Plastic debris was characterized by attenuated total reflection Fourier-transform infrared spectrometry. The organic contaminants were extracted from plastics by ultrasonic extraction with methanol and quantified by stir bar sorptive extraction coupled to gas chromatography-mass spectrometry (GC-MS). In two areas, the desorption of these contaminants from plastic debris to seawater during 24 h was also evaluated. The contaminant groups considered in this study (polycyclic aromatic hydrocarbons (PAHs), personal care products (PCPs), current use pesticides (CUPs), organochlorinated compounds (OCPs, including polychlorinated biphenyls and organochlorinated pesticides) and plastic additives were found in polymers from the three areas. The most abundant contaminants were plastic additives and PCPs, underlining the relevance of the leaching of plastic components, and urban and tourism activities as typical pollution sources in the coastal areas. In general, large piece-to-piece variability was found for all polymers and areas mainly as a consequence of their different origin, exposition time, use and surface-to-volume ratio. This fact difficulted the visualization of significant differences between polymers or areas, but for CUPs, whose concentrations were significantly higher in Cape Cope than in the other areas due to the influence of close agricultural activities. PCPs and CUPs were desorbed partially in seawater for 24 h, particularly the most hydrophilic compounds such as triazines and other CUPs. However, a significant fraction of other contaminants (mainly PAHs) was retained, which suggests they can be transported far away from their origin.