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Many deep‐water fish populations, being K‐selected species, have little resilience to overexploitation and may be at serious risk of depletion as a consequence. Sea warming represents an additional threat. In this study, the condition, or health, of several populations of common ling (Molva molva), blue ling (Molva dypterygia) and Mediterranean or Spanish ling (Molva macrophthalma) inhabiting different areas in the North Atlantic and the Mediterranean was evaluated, to shed light on the challenges these deep‐water species are facing in the context of fishing activity and a warming climate. The data on the condition of Molva populations which are analysed here have been complemented with data on abundance and, for the southernmost species (Mediterranean ling), with two other health indicators (parasitism and hepato‐somatic index). Despite some exceptions (e.g., common ling in Icelandic waters), this study shows that the condition of many populations of Molva species in the northeastern Atlantic and the Mediterranean Sea has worsened, a trend which, in recent decades, has usually been found to be accompanied by a decline in their abundance. In addition, the poor health status of most populations of common ling, blue ling and Mediterranean ling considered in this analysis points to a lower sustainability of these populations in the future. Overall, the health status and abundance of Molva populations in the northeastern Atlantic and the Mediterranean suggest that only some populations located in the North Atlantic may be able to rebuild, whereas the populations in southern North Atlantic and the Mediterranean, which are probably most at risk from sea warming, are facing serious difficulties in doing so. In the context of fisheries and global warming, this study's results strongly indicate that management bodies need to consider the health status of many of the populations of Molva species, particularly in southern European waters, before implementing their decisions. [ABSTRACT FROM AUTHOR]

Abstract Inter-species quota flexibility (IQF) is a new management tool made available to fishery managers in the reformed European Common Fisheries Policy (CFP) launched in 2013. IQF regulates a limited transfer between stock-specific total allowable catches (TAC), the main measure of stock conservation in CFP set in accordance with precautionary or, where possible, analytically estimated levels of maximum sustainable yield (MSY). IQF is intended to mitigate the various potential conflicts in the management of multi-species fisheries resulting from stricter catch limitations, which, in turn, are due to the newly-introduced landing obligation for all catches of TAC-regulated stocks. In this paper, the management implications of inter-species flexibility are evaluated by modelling various scenarios of individual and multiple multi-species fisheries exploiting virtual stocks of different sizes and productivity. The results reveal that IQF is rather ineffectual if sustainable stock-specific management goals are similar in terms of exploitation rate. However, if these goals are modified in response to potential ecological conservation needs or market considerations – which would reflect reality more closely – IQF may offer a frequently applicable and effective tool. Simulations carried out in this study demonstrate that IQF may support the use of quotas by increasing fishing opportunities of by-catch species, which are then subtracted from the target stock allowances. However, multiple and jointly managed multi-species fisheries frequently appear limited due to reduced fishing opportunities of target stocks, which may prevent the progressive application of IQF. As such, IQF is helpful for certain specific fisheries management, rather than as a tool for broader management approaches jointly applied to different fishing strategies. It is concluded that the application of IQF may undermine the politically-agreed and fixed quota-sharing rule among European member states (i.e. the "relative stability") and also lacks a reference to F MSY ; i.e., it remains to be clarified whether the application of IQF would result in tolerable levels of short term overfishing of by-catch stocks with regard to MSY. Highlights • European fishery management. • Strategy evaluation. • Inter-species quota flexibility. • Support of fisheries specific management. [ABSTRACT FROM AUTHOR]

The three main pillars of the European Common Fisheries Policy, reformed in 2013, consist of minimizing ecological impacts; implementing sustainable exploitation defined by maximum sustainable yield (MSY) for regulated species and introducing landing obligations aimed at reducing the wasteful practice of discarding unwanted catches. These three key elements constitute major challenges for fisheries, their management and fishery scientists whose goal is to provide objective advice. We demonstrate that limiting sustainable catch options may pose rigorous constraints on fishing activities, in particular on so-called mixed fisheries targeting more than one individual stock. In a situation where there are complex restrictions comprising multiple management goals which are sometimes conflicting (e.g. the ‘choke effects’ of reduced catch opportunities due to specific stock conservation needs or market conditions), we propose the application of specific measures for specific fisheries, i.e. deviation from traditional fishery selection patterns, as an option to avert significant losses in yield and economic revenue. Fisheries-specific contributions to general management goals, including unwanted effects, shall be evaluated. Individual fisheries may benefit accordingly through multi-annual management plans with regional-scale reconciliation of sustainable exploitation of living natural resources, food security and socio-economy as potential key elements. [ABSTRACT FROM AUTHOR]

Living marine resources have strong links with human health and well-being that are complex, still not well understood and that are being modified by global change. This review attempts to illustrate how fishing activities, aquaculture and climate change are challenging these connections and the consequent health risks and benefits posed to citizens. Although global change may provide some positive aspects for human health locally, such as new sources of omega-3, overall it will exacerbate existing seafood security and safety concerns. Unsustainable fishing and aquaculture practices, and climate change, particularly sea warming, ocean acidification and changes in riverine runoff, are threatening not only the protein and fish oil/ omega-3 supplies available for consumers, but also raising ecological and health concerns associated with the increase of contaminants, microbes and biotoxins. In this context, we propose a number of management measures that could mitigate the negative effects of global change on seafood, and hence on human health and well-being. [ABSTRACT FROM AUTHOR]

Abstract: Exploited fish and shellfish stocks in European marine waters underlie the Common Fisheries Policy (CFP). The next round of reform of the CFP is due for completion in 2012. The exploitation at maximum sustainable yield (MSY) may be confirmed as the common environmental objective for good environment status (GES) of exploited fish and shellfish stocks of the reformed CFP and the Marine Strategy Framework Directive (MSFD). The foreseen time horizon to achieve or maintain GES by 2020 appears inconsistent with the World Summit on Sustainable Development UN agreement in 2002, which stipulates that maintenance or restoring of stocks to produce MSY be realized by 2015. The MSFD requires instead that by 2015 the national programmes of measures be designed in order to become operational the following year (2016). The MSFD significantly strengthens Member States’ competences and responsibilities to maintain or achieve GES for all exploited fish and shellfish stocks inside territorial waters and the exclusive economic zones (EEZs) with common goals. This will inevitably guide future European Fisheries Council decisions towards long term objectives even at regional levels instead of short term national socio-economic concerns. With such provisions, MSFD is thought to foster and harmonise European fisheries management with ecosystem approaches. For reasons of simplification, the future revision of the CFP should cover all exploited fish and shellfish stocks in all European Seas including territorial zones and EEZs. Member States will need to prepare both for the increased scientific advisory and monitoring efforts expected. The eligibility of additional costs for the Data Collection Framework (DCF) needs to be discussed and decided as soon as these costs are identified and quantified by the competent authorities. [Copyright &y& Elsevier]

Rätz, H-J., Bethke, E., Dörner, H., Beare, D., and Gröger, J. 2007. Sustainable management of mixed demersal fisheries in the North Sea through fleet-based management—a proposal from a biological perspective. – ICES Journal of Marine Science, 64: 652–660. Cod, haddock, whiting, saithe, plaice, sole, and Norway lobster are main target species for the mixed demersal fisheries of the North Sea, Skagerrak, and eastern Channel. Management by total allowable catch has not been able to constrain exploitation of individual species, so the potential for a fleet-specific effort management system to reach the management objectives established for the stocks is simulated. Relative fleet-specific effort factors are estimated based on the sum of partial fishing mortalities of the species caught, weighted by the stocks at risk of reduced reproductive capacity. The strategy promotes the use of selective gear and levies non-selective gear. The factors were applied in medium-term simulations of the annual decision process in accordance with existing and proposed multi-annual management plans (including for cod recovery). Strict effort reduction would be required for fleets targeting cod, plaice, or sole (specifically large- and medium-mesh trawler fleets, beam trawlers, and gillnetters) for ∼5 years, reducing the exploitation rates on all stocks substantially. Cod and plaice are predicted to recover by 2010 and cod catches to exceed recent levels continually, with the more selective longliners and some other gear types profiting most. Management objectives for cod dominate annual effort adjustments, resulting in substantial underexploitation of other stocks. However, even a 10% bias caused by non-compliance would largely halt cod recovery and the restoration of other stocks. [ABSTRACT FROM PUBLISHER]

Gröger, J. P., Rountree, R. A., Missong, M., and Rätz, H-J. 2007. A stock rebuilding algorithm featuring risk assessment and an optimization strategy of single or multispecies fisheries. – ICES Journal of Marine Science, 64: 1101–1115. We present a simple but flexible stock-rebuilding algorithm model that features ideas of risk assessment, with all constraints set up explicitly, and with clear optimality for controlling fishing effort (or fishing mortality) and maximizing landings (or economic value). In contrast to the conventional approach, our approach does not predict future stock development from historical stock dynamics, but provides directly optimal annual F values and associated optimum catch quotas for a given planning horizon. Hence, the F values are not estimated retrospectively, but are realizations of a control variable created through the optimization process. The optimal solution is based on maximization of a non-linearly constrained objective function for catch or yield, whereas the constraints inter alia include biomass targets, F limits, and stable catch. We present the basic theory together with selected model variants, such as inclusion of biological interactions and integration of elements of risk assessment. The optimization procedure outlined here is not only “risk averse” but a risk minimization procedure in itself. It can be applied in a deterministic or stochastic decision-making process as well as within a single or multispecies context. We illustrate the approach with a simplified (deterministic) multispecies fisheries management and a (stochastic) single-species risk assessment example. [ABSTRACT FROM PUBLISHER]

Growth variation was estimated from mean lengths-at-ages 4 and 5 for Atlantic cod off Greenland based on 52,973 fish taken from commercial and scientific catches from 1955 to 2002. Mean length-at-age values were corrected for area and seasonal effects, and significant growth reductions occurred during the 1960s and from the mid-1970s until the mid-1980s. Annual growth rates of cod in Greenland waters during the most recent decade (1993–2002) were consistently among the highest recorded. Statistical growth models accounting for temperature, fishing mortality, and stock abundance effects were constructed. Multiple linear regressions revealed significant positive temperature effects on growth of both age groups and a significant negative stock density effect on length-at-age 4. Correlations between exploitation intensity and length-at-age were statistically insignificant. During the period 1955–2002, the number of recruits at age 3 was significantly correlated with the Greenland cod spawning-stock biomass, June water temperature on top of Fyllas Bank (West Greenland), and Iceland cod recruitment. All factors had a positive effect on the number of Greenland recruits and, combined, accounted for 60% of the observed variation. Spawning stock size was, by far, the most important factor contributing to recruitment variability, while June water temperature below 1°C and Iceland recruits below 150 million never coincided with high year-class strength in Greenland during the past 50 years. Thus, previous conclusions regarding a close relation between the Greenland and Icelandic cod stocks might need to be reconsidered in the light of a continued recruitment failure in Greenland waters over the two most recent decades, despite the improved environmental conditions and near-average recruitment of the Icelandic stock. The low precision of the recruitment model, however, prevents reliable predictions in the short or medium term, but a substantial short-term recovery of the Greenland cod stock remains unlikely. [Copyright &y& Elsevier]

Atlantic cod in West Greenland waters have varied greatly in abundance and distribution in the past decades. Strong year classes yielded good catches inshore and offshore in the late 1980s, but since then cod have been nearly absent offshore and the inshore fishery has been depressed, though there has been a small increase inshore over the past few years. Different components contribute to the Greenland cod stock, and re-analysed tagging experiments indicate that migration behaviour differs between them. Inshore cod are sedentary, with almost no migration between different fjord systems. In contrast, there are many cases of alongshore migration of cod tagged on the offshore fishing banks. Further, observations have been made of occasional migrations from offshore to inshore, notably so in years of good recruitment originating from Icelandic waters. [Copyright &y& Elsevier]

A comparative analysis of the fish condition (Fulton’s K) of 10 cod stocks in the north Atlantic in relation to the temperature of their habitat, growth rates and their reproductive potential is presented. It is shown that the cod stocks in the north Atlantic display different levels of mean condition, which is partly due to the different temperature regimes of their habitats. Cod living in colder waters, e.g. Greenland, Labrador and Grand Bank stocks, were found to be in poorer condition than cod living in warmer waters, e.g. North Sea and Irish Sea stocks.Poor condition causes reduced productivity in terms of slow growth and low recruitment potential. Stocks in better condition display significantly higher weights at age 4 than stocks in poor condition. The a coefficients (function’s slopes) obtained from standardised Ricker’s recruitment–spawning stock biomass (SSB) relationships were defined as indicators for the recruitment potential of stocks. These a coefficients were found to be positively correlated with the mean condition factor of the 10 stocks analysed. This indicates that stocks consisting of individuals in poor condition appear to be very susceptible to reduced recruitment at low SSB, while the stocks that consist of fish in good condition seem to behave more robustly with a higher probability of good recruitment at low SSB. The positive effect of the cod condition on their reproductive potential generally implies that the stocks in good condition in the temperate regions of the northeast and west Atlantic can sustain higher exploitation rates than stocks in poor condition in the colder regimes of the northwest Atlantic (Greenland, Labrador and Grand Bank). This is confirmed by the positive relationship established between the estimated biological management reference points Fmed and the mean cod condition factors, as well as by the recent status of these stocks. [Copyright &y& Elsevier]