- Email: [email protected]
Tackling the old familiar problems of pollution, habitat alteration and overfishing will help with adapting to climate change
Marine Pollution Bulletin 56 (2008) 1957–1958
Contents lists available at ScienceDirect
Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul
Editorial
Tackling the old familiar problems of pollution, habitat alteration and overfishing will help with adapting to climate change Marine ecosystems and the threats confronting them have become an almost daily topic for coverage and debate in the media. The impacts of global warming, ice melt and acidification on fish stocks, polar bears, corals, jellyfish, seabirds and other marine taxa feature regularly on our front pages, often backed by studies reporting alarming new evidence of rapid change. These are worthy subjects of concern, but in most cases there is no obvious remedy to prevent undesirable changes; these are unintended consequences of global changes, which can only be reined in gradually by the long slow process of mitigation and reducing greenhouse gas emissions. Spreading gloom without suggesting solutions is not a good idea. Options for adaptation are limited, but they do exist, because we can control some factors affecting sensitivity of some marine biota to climate. The impact of climate change depends on the scale of change, but also on the sensitivity of particular species or ecosystems. We ourselves experience increased sensitivity to illness (or to criticism) when we are stressed, and in a similar way the sensitivity of marine biota depends on the degree to which other factors such as fishing, habitat alteration and pollution are stressing individuals and populations. Why does a fish population become more sensitive to environmental factors when it is exploited? A number of processes may combine to produce this effect. The first is a consequence of the reduced life expectancy and truncated age structure due to fishing mortality (Ottersen et al., 2006). Fish populations in which the natural life-span is long (some fish can survive and breed for many decades) are able to withstand long periods of environmental conditions which adversely affect survival of their offspring, but this buffering capacity is reduced when the age structure of the breeding population is truncated due to fishing. The second is that the removal of older fish can have a disproportionate effect on larval survival and recruitment in species where older fish produce more viable offspring and spawn over a wider geographic and seasonal span (Begg and Marteinsdóttir, 2003). A third kind of effect is due to reduced spatial heterogeneity or geographic substructure (meta-population structure) which is characteristic of many fish stocks (Hilborn et al., 2003). A fourth process is reduction of genetic variability within the stock. Increased sensitivity to environmental factors due to a combination of these processes has been demonstrated in a number of heavily exploited stocks (Perry et al., in press; Planque et al., in press; Hsieh et al., 2006) and measures which reduce such stresses will boost resilience to climate and enhance adaptation. The age truncation effects of heavy fishing may also result in increasingly unstable population dynamics due to changes in demographic parameters such as intrinsic growth rates and non-linear effects
0025-326X/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.marpolbul.2005.09.002
of process noise (Anderson et al., 2008). There is therefore a particularly compelling case for tackling the prevailing overfishing of many stocks, because in addition to increasing their resilience (and decreasing variability) this can also bring us closer to two other desirable goals: maximising yields from those stocks and reducing CO2 emissions in their capture. FAO estimate that about one quarter of all fish stocks are overexploited, depleted or recovering from overexploitation and that half of all stocks are fully exploited (FAO Fisheries Department, 2007). Reductions in the level of fishing will help to restore over-exploited and depleted stocks. Fully exploited stocks can also benefit from lower levels of fishing, which would result in higher stock biomass levels and less risk from a succession of poor years of recruitment. About 1.2% of global oil consumption is used in fisheries. A European life-cycle analysis of fish products found that the catching sector was the main contributor to global warming in the production chain (Thrane, 2006). Beam trawling, for example, consumes 4 kg of fuel per kg of fish landed. A reduction in the level of fishing will help to reduce fuel consumption because the resultant increases in fishable biomasses would provide higher catch rates. Of course improved, more fuel efficient catching methods would also reduce energy use in fish capture. Some existing fishery-management measures, such as catch quotas, may reduce energy efficiency and add to greenhouse gas emissions. Two messages follow: Reduction of fishing effort is a triple win strategy, which produces benefits in relation to (i) maximising sustainable yields (ii) adaptation of fish stocks and marine ecosystems to climate impacts and (iii) mitigation by reducing greenhouse gas emissions. It is also a ‘‘no regret” strategy in relation to climate change, because the benefits apply irrespective of how climate changes. Our impacts on marine ecosystems are a result of several factors, some of which are old and familiar (pollution, habitat disturbance, overfishing). Some of the most effective actions which we can take to tackle the new concerns over climate impacts are to reinforce our efforts to deal with the old familiar problems, such as overfishing.
References Anderson, C.N.K., Hsieh, C.h., Sandin, S.A., Hewitt, R., Hollowed, A., Beddington, J., May, R.M., Sugihara, G., 2008. Why fishing magnifies fluctuations in fish abundance. Nature 452, 835–839. Begg, G.A., Marteinsdóttir, G., 2003. Spatial and temporal partitioning of spawning stock biomass: effects of fishing on the composition of spawners. Fisheries Research 59, 343–362. FAO Fisheries Department, 2007. The State of World Fisheries and Aquaculture (SOFIA) 2006. FAO.
1958
Baseline / Marine Pollution Bulletin 56 (2008) 1957–1958
Hilborn, R., Quinn, T.P., Schindler, D.E., Rogers, D.E., 2003. Biocomplexity and fisheries sustainability. Proceedings of the National Academy of Sciences of the United States of America 100, 6564–6568. Hsieh, C., Reiss, C.S., Hunter, J.R., Beddington, J.R., May, R.M., Suguhara, G., 2006. Fishing elevates variability in the abundance of exploited species. Nature 443, 859–862. Ottersen, G., Hjermann, D.Ø., Stenseth, N.C., 2006. Changes in spawning stock structure strengthen the link between climate and recruitment in a heavily fished cod (Gadus morhua) stock. Fisheries Oceanography 15, 230–243. Perry, R.I., Cury, P., Brander, K., Jenning, S., Möllmann, C., Planque, B. in press. Sensitivity of marine systems to climate and fishing: concepts, issues and management responses. Journal of Marine Systems.
Planque, B., Fromentin, J.-M., Cury, P., Drinkwater, K. F., Jennings, S., Perry, R.I., Kifani, S. in press. How does fishing alter marine populations and ecosystems sensitivity to climate? Journal of Marine Systems. Thrane, M., 2006. LCA of Danish fish products – New methods and insights. The International Journal of Life Cycle Assessment 11 (1), 66–74.
Keith Brander DTU Aqua, Denmark E-mail address: [email protected]
doi:10.1016/j.marpolbul.2005.09.002
‘Best paper’ prize of 2008
Elsevier Science and Marine Pollution Bulletin present an annual prize of $1000 for the paper published in this journal during the preceding year which the editor and members of the editorial board considers to be very important. In this first year, papers published between summer 2007 and summer 2008 were looked at in this regard. The paper chosen is that by Anna Occhipinti-Ambrogi, on ‘Global change and marine communities: alien species and climate change’ (reference below). The criteria on which a judgment is made were stated in Barranguet and Sheppard (2007). The paper chosen this year is a review, which was part of a collection of reviews on marine bioinvasions, and it concerns an issue that is changing rapidly as the global marine environment changes. By examining the process of introduction of an alien species into a new habitat, the paper takes into account the possible ways of interactions (at different stages of the invasion and at different levels of ecosystem organization) with the changes in the physical environ-
doi:10.1016/j.marpolbul.2008.11.004
ment induced by climate change. It is a challenging, albeit daunting, field for scientific investigation. One point that should be made is that this choice of ‘best paper’ was not made by reference to numbers of downloads or citation, but on the basis only of the paper itself. Numerical measures in any case are strongly influenced by date within the year of publication and other factors. This paper was judged to be very topical, important, and likely to help open up this important area of work in future. Our congratulations to Anna Occhipinti-Ambrogi from the University of Pavia, Italy.
References Barranguet, C., Sheppard, C.R.C., (2007). Marine Pollution Bulletin annual prize. Marine Pollution Bulletin 54, 369. Occhipinti-Ambrogi, A., (2007). Global change and marine communities: alien species and climate change. Marine Pollution Bulletin 55, 342–353.
Contents lists available at ScienceDirect
Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul
Editorial
Tackling the old familiar problems of pollution, habitat alteration and overfishing will help with adapting to climate change Marine ecosystems and the threats confronting them have become an almost daily topic for coverage and debate in the media. The impacts of global warming, ice melt and acidification on fish stocks, polar bears, corals, jellyfish, seabirds and other marine taxa feature regularly on our front pages, often backed by studies reporting alarming new evidence of rapid change. These are worthy subjects of concern, but in most cases there is no obvious remedy to prevent undesirable changes; these are unintended consequences of global changes, which can only be reined in gradually by the long slow process of mitigation and reducing greenhouse gas emissions. Spreading gloom without suggesting solutions is not a good idea. Options for adaptation are limited, but they do exist, because we can control some factors affecting sensitivity of some marine biota to climate. The impact of climate change depends on the scale of change, but also on the sensitivity of particular species or ecosystems. We ourselves experience increased sensitivity to illness (or to criticism) when we are stressed, and in a similar way the sensitivity of marine biota depends on the degree to which other factors such as fishing, habitat alteration and pollution are stressing individuals and populations. Why does a fish population become more sensitive to environmental factors when it is exploited? A number of processes may combine to produce this effect. The first is a consequence of the reduced life expectancy and truncated age structure due to fishing mortality (Ottersen et al., 2006). Fish populations in which the natural life-span is long (some fish can survive and breed for many decades) are able to withstand long periods of environmental conditions which adversely affect survival of their offspring, but this buffering capacity is reduced when the age structure of the breeding population is truncated due to fishing. The second is that the removal of older fish can have a disproportionate effect on larval survival and recruitment in species where older fish produce more viable offspring and spawn over a wider geographic and seasonal span (Begg and Marteinsdóttir, 2003). A third kind of effect is due to reduced spatial heterogeneity or geographic substructure (meta-population structure) which is characteristic of many fish stocks (Hilborn et al., 2003). A fourth process is reduction of genetic variability within the stock. Increased sensitivity to environmental factors due to a combination of these processes has been demonstrated in a number of heavily exploited stocks (Perry et al., in press; Planque et al., in press; Hsieh et al., 2006) and measures which reduce such stresses will boost resilience to climate and enhance adaptation. The age truncation effects of heavy fishing may also result in increasingly unstable population dynamics due to changes in demographic parameters such as intrinsic growth rates and non-linear effects
0025-326X/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.marpolbul.2005.09.002
of process noise (Anderson et al., 2008). There is therefore a particularly compelling case for tackling the prevailing overfishing of many stocks, because in addition to increasing their resilience (and decreasing variability) this can also bring us closer to two other desirable goals: maximising yields from those stocks and reducing CO2 emissions in their capture. FAO estimate that about one quarter of all fish stocks are overexploited, depleted or recovering from overexploitation and that half of all stocks are fully exploited (FAO Fisheries Department, 2007). Reductions in the level of fishing will help to restore over-exploited and depleted stocks. Fully exploited stocks can also benefit from lower levels of fishing, which would result in higher stock biomass levels and less risk from a succession of poor years of recruitment. About 1.2% of global oil consumption is used in fisheries. A European life-cycle analysis of fish products found that the catching sector was the main contributor to global warming in the production chain (Thrane, 2006). Beam trawling, for example, consumes 4 kg of fuel per kg of fish landed. A reduction in the level of fishing will help to reduce fuel consumption because the resultant increases in fishable biomasses would provide higher catch rates. Of course improved, more fuel efficient catching methods would also reduce energy use in fish capture. Some existing fishery-management measures, such as catch quotas, may reduce energy efficiency and add to greenhouse gas emissions. Two messages follow: Reduction of fishing effort is a triple win strategy, which produces benefits in relation to (i) maximising sustainable yields (ii) adaptation of fish stocks and marine ecosystems to climate impacts and (iii) mitigation by reducing greenhouse gas emissions. It is also a ‘‘no regret” strategy in relation to climate change, because the benefits apply irrespective of how climate changes. Our impacts on marine ecosystems are a result of several factors, some of which are old and familiar (pollution, habitat disturbance, overfishing). Some of the most effective actions which we can take to tackle the new concerns over climate impacts are to reinforce our efforts to deal with the old familiar problems, such as overfishing.
References Anderson, C.N.K., Hsieh, C.h., Sandin, S.A., Hewitt, R., Hollowed, A., Beddington, J., May, R.M., Sugihara, G., 2008. Why fishing magnifies fluctuations in fish abundance. Nature 452, 835–839. Begg, G.A., Marteinsdóttir, G., 2003. Spatial and temporal partitioning of spawning stock biomass: effects of fishing on the composition of spawners. Fisheries Research 59, 343–362. FAO Fisheries Department, 2007. The State of World Fisheries and Aquaculture (SOFIA) 2006. FAO.
1958
Baseline / Marine Pollution Bulletin 56 (2008) 1957–1958
Hilborn, R., Quinn, T.P., Schindler, D.E., Rogers, D.E., 2003. Biocomplexity and fisheries sustainability. Proceedings of the National Academy of Sciences of the United States of America 100, 6564–6568. Hsieh, C., Reiss, C.S., Hunter, J.R., Beddington, J.R., May, R.M., Suguhara, G., 2006. Fishing elevates variability in the abundance of exploited species. Nature 443, 859–862. Ottersen, G., Hjermann, D.Ø., Stenseth, N.C., 2006. Changes in spawning stock structure strengthen the link between climate and recruitment in a heavily fished cod (Gadus morhua) stock. Fisheries Oceanography 15, 230–243. Perry, R.I., Cury, P., Brander, K., Jenning, S., Möllmann, C., Planque, B. in press. Sensitivity of marine systems to climate and fishing: concepts, issues and management responses. Journal of Marine Systems.
Planque, B., Fromentin, J.-M., Cury, P., Drinkwater, K. F., Jennings, S., Perry, R.I., Kifani, S. in press. How does fishing alter marine populations and ecosystems sensitivity to climate? Journal of Marine Systems. Thrane, M., 2006. LCA of Danish fish products – New methods and insights. The International Journal of Life Cycle Assessment 11 (1), 66–74.
Keith Brander DTU Aqua, Denmark E-mail address: [email protected]
doi:10.1016/j.marpolbul.2005.09.002
‘Best paper’ prize of 2008
Elsevier Science and Marine Pollution Bulletin present an annual prize of $1000 for the paper published in this journal during the preceding year which the editor and members of the editorial board considers to be very important. In this first year, papers published between summer 2007 and summer 2008 were looked at in this regard. The paper chosen is that by Anna Occhipinti-Ambrogi, on ‘Global change and marine communities: alien species and climate change’ (reference below). The criteria on which a judgment is made were stated in Barranguet and Sheppard (2007). The paper chosen this year is a review, which was part of a collection of reviews on marine bioinvasions, and it concerns an issue that is changing rapidly as the global marine environment changes. By examining the process of introduction of an alien species into a new habitat, the paper takes into account the possible ways of interactions (at different stages of the invasion and at different levels of ecosystem organization) with the changes in the physical environ-
doi:10.1016/j.marpolbul.2008.11.004
ment induced by climate change. It is a challenging, albeit daunting, field for scientific investigation. One point that should be made is that this choice of ‘best paper’ was not made by reference to numbers of downloads or citation, but on the basis only of the paper itself. Numerical measures in any case are strongly influenced by date within the year of publication and other factors. This paper was judged to be very topical, important, and likely to help open up this important area of work in future. Our congratulations to Anna Occhipinti-Ambrogi from the University of Pavia, Italy.
References Barranguet, C., Sheppard, C.R.C., (2007). Marine Pollution Bulletin annual prize. Marine Pollution Bulletin 54, 369. Occhipinti-Ambrogi, A., (2007). Global change and marine communities: alien species and climate change. Marine Pollution Bulletin 55, 342–353.