Hollowed, A. B., Barange, M., Beamish, R., Brander, K., Cochrane, K., Drinkwater, K., Foreman, M., Hare, J., Holt, J., Ito, S-I., Kim, S., King, J., Loeng, H., MacKenzie, B., Mueter, F., Okey, T., Peck, M. A., Radchenko, V., Rice, J., Schirripa, M., Yatsu, A., and Yamanaka, Y. 2013. Projected impacts of climate change on marine fish and fisheries. – ICES Journal of Marine Science, 70: 1023–1037. This paper reviews current literature on the projected effects of climate change on marine fish and shellfish, their fisheries, and fishery-dependent communities throughout the northern hemisphere. The review addresses the following issues: (i) expected impacts on ecosystem productivity and habitat quantity and quality; (ii) impacts of changes in production and habitat on marine fish and shellfish species including effects on the community species composition, spatial distributions, interactions, and vital rates of fish and shellfish; (iii) impacts on fisheries and their associated communities; (iv) implications for food security and associated changes; and (v) uncertainty and modelling skill assessment. Climate change will impact fish and shellfish, their fisheries, and fishery-dependent communities through a complex suite of linked processes. Integrated interdisciplinary research teams are forming in many regions to project these complex responses. National and international marine research organizations serve a key role in the coordination and integration of research to accelerate the production of projections of the effects of climate change on marine ecosystems and to move towards a future where relative impacts by region could be compared on a hemispheric or global level. Eight research foci were identified that will improve the projections of climate impacts on fish, fisheries, and fishery-dependent communities.

Plastic waste accumulating in the global ocean is an increasingly threatening environmental issue. To date, the floating and thus most visible fraction of ocean plastic pollution has been mapped at global scale. Yet, large knowledge gaps exist in our current understanding of the transport and transformation processes of positively buoyant plastic debris at the sea surface. Observations at sea typically report an apparent scarcity of microplastics (<5 mm) relative to the expected abundance-size distribution based on fragmentation of larger plastic objects. Here, we provide a comprehensive study on the relative abundance of microplastics (>500 µm) and mesoplastics (0.5–5 cm) in the surface waters of the eastern North Pacific Ocean using data from 1136 040 plastic fragments collected by 679 neuston trawl deployments between 2015 and 2019. Our results reveal that the apparent microplastic scarcity is not uniformly distributed across the region. Instead, we show that the relative abundance of floating microplastics increases from the outside to the inside of the North Pacific Garbage Patch. We hypothesize that this observation could be explained by (i) a spatially variable microplastic removal due to spatial differences in ocean productivity, (ii) a differential dispersal of micro- vs. mesoplastics with a preferential accumulation of microplastics in the subtropical gyre, and/or (iii) the timescales associated with transport and fragmentation of plastic objects at the ocean surface with older, more degraded, floating plastic accumulation in subtropical gyres. The results presented here highlight that global estimates of the accumulation and removal of positively buoyant microplastics need to consider spatial aspects such as variations in ocean productivity, the dominant physical transport processes in a given area, as well as the time needed for a plastic object to reach the specific offshore location.

The Pacific Research Institute of Fisheries and Oceanography (TINRO) in Vladivostok, Russia, conducted 12 major biological surveys in the western Bering Sea in 1986–1995. During these surveys, sockeye salmon Oncorhynchus nerka were sampled with a new pelagic trawl. We used salmon catch, age and growth, and diet data from the TINRO surveys to evaluate the role of sockeye salmon in the structure and function of pelagic communities in the western Bering Sea. Estimates of abundance (numbers and biomass) showed large annual and seasonal fluctuations in the western Bering Sea. Immature and maturing sockeye salmon migrated to the western Bering Sea in late spring from their winter (December–May) feeding grounds in the North Pacific Ocean. Maturing sockeye salmon were distributed in the western Bering Sea from June to early August before returning to their natal spawning rivers. In late August, smolts (age n.0, where the n indicates an ocean‐age cohort and zero indicates the number of ocean annuli) began to move from coastal to offshore waters, where the largest numbers occurred in September–November. We inferred from catch data that most of the other age‐groups of sockeye salmon left the western Bering Sea by the end of November and moved southward to the North Pacific Ocean. The analyses indicated that sockeye salmon fed in the seasonal thermocline layers, where they were important consumers of interzonal zooplankton and micronektonic organisms. The dietary ration of sockeye salmon was high. The high growth rates of sockeye salmon in the western Bering Sea were comparable to those in the North Pacific Ocean. The wide distribution, numerous trophic linkages, high rations, and high growth rate of sockeye salmon establish their important role in pelagic communities of the western Bering Sea.

Following a brief review of their biology, this contribution is an attempt to provide a global overview of the catches of mesopelagic fishes (of which 2.68 million tonnes were officially reported to the FAO) throughout the world ocean from 1950 to 2018, to serve as a baseline to a future development of these fisheries. The overview is based on a thorough scanning of the literature dealing with commercial or experimental fisheries for mesopelagics and their catches, and/or the mesopelagic bycatch of other fisheries. All commercial (industrial and artisanal) fisheries for mesopelagic fishes were included, as well as experimental fisheries of which we were aware, while catches performed only to obtain scientific samples were omitted. The processes of generating bycatch and causing discards are discussed, with emphasis on Russian fisheries. From peer-reviewed and gray literature, we lifted information on mesopelagic fisheries and assembled it into one document, which we then summarized into two text tables with catch data, one by country/region, the other by species or species groups.

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