A marine monitoring team implants a tracking transmitter on a gray reef shark (Carcharhinus amblyrhynchos) before releasing the shark at Palmyra Atoll in the equatorial Northern Pacific. Image credit: Tim Calver for The Nature Conservancy
This Nature Longread essay first appeared in SNAP Magazine, which features great writing on the intersection of nature and human well-being as part of the website of the Science for Nature and People (SNAP) collaboration. Read more SNAP Magazine articles and learn more about the SNAP collaboration.
By Ray Hilborn, professor of aquatic and fisheries science, University of Washington
The debate raging within the conservation community over “new conservation” appears to be essentially a religious war, with doctrinal beliefs well defined and the rancor and defamation appearing to grow each month. In essence, the “new conservation” argues that the major gains in biodiversity protection will be made in human-used environments and by working with communities and industries that use these environments rather than by the use of protected areas (Kareiva and Marvier 2012).
The actual rancor seems to stem more from a philosophical question of whether biodiversity should be conserved for its own sake or because it is valued by humans (Soule 2013) and from criticism of some of the icons of the conservation movement in other writings by Kareiva (Karevia et al. 2011). These debates need to be set aside and the energy of the conservation community needs to be focused on what will work best to protect biodiversity.
Marine conservation, where little energy has been expended until the last few decades, represents the new frontier of conservation. Marine biodiversity is under threat from a range of factors, but I would like to focus on the impacts of fishing on biodiversity, and specifically overfishing of marine species and communities and associated ecosystem changes, mortality of non-target species, and the impacts of fishing gear on habitat.
Fishing by its nature reduces the abundance of target species, changes the age- and size structure, and can change the trophic structure of marine ecosystems. Non-target species are commonly caught and killed by fishing gear, and this is of particular concern when endangered species or protected species such as turtles, marine mammals and marine birds are concerned. Mobile bottom-contact fishing gear (trawls and dredges) can dramatically modify bottom habitats.
Initiatives using the “old conservation” of protected areas have been hard at work. It is estimated that marine NGOs funded through U.S. foundations and their own fund raising spend on the order of $300 million per year on marine conservation (California Environmental Associates 2012), with much of that funding directed towards protected areas advocacy. These efforts have led to major successes both in international acceptance of targets for protected areas (the International Convention on Biological Diversity CBD has an agreed target of 10% of the oceans in no-take areas by 2020) and in getting areas protected. Protected area advocates have been particularly successful in the United States and Australia, where large areas of the ocean have been given protection from fishing.
“Perhaps the most striking successes of the ‘new conservation’ have been in the reduction of by-catch of threatened or protected species.”
The “new conservation” has been equally active in the marine space, some of it funded by the same NGOs and foundations. Perhaps most prominent has been the move to seafood certification. The Marine Stewardship Council, an independent NGO initiated by a partnership between industry (Unilever) and an NGO (WWF), has worked with retailers, governments and industry groups to set standards, certify fisheries as well managed and help fisheries move towards meeting the standards.
Many retailers have made commitments to sell only certified seafood within the next few years, and the number of certification schemes is proliferating. Seafood certification is a classic example of the “new conservation” in that partnerships with industry and the conservation movement are altering the behavior of the fishing industry and leading to better biodiversity protection (Gutierrez et al. 2012).
Freshly caught Pacific cod. Image credit: Nick Rahaim/Flickr through a Creative Commons license.
Perhaps the most striking successes of the “new conservation” have been in the reduction of by-catch of threatened or protected species. Because of political pressures and legal requirements to reduce such by-catch, fishing industries have reduced by-catch of dolphins in the eastern tropical Pacific tuna fisheries by 99% (Hall et al. 2000); reduced the by-catch of sea birds in Antarctic longline fisheries by 99% (Cox et al. 2007); the by-catch of turtles in the Hawaii longline fishery by 95% (Moore et al. 2009); and the by-catch of turtles in the SE shrimp trawl fisheries by 94% (Finkbeiner et al. 2011).
Closed areas are a very blunt and not very effective instrument to protect the biodiversity from this kind of by-catch, although closed areas have generally been part of the package. A recent review of by-catch mitigation for three species including a turtle, an albatross and a small cetacean (Senko et al. 2013) concluded: “Time–area closures appeared to be of limited effectiveness for the focal species.” Many have argued for closing biodiversity hot-spots (Worm et al. 2003). But since many of the species of concern are highly mobile, closed areas will have the effect of intensifying fishing effort elsewhere with little real reduction in mortality of these species.
“Protection of marine biodiversity illustrates a range of ways that the new conservation working with industry groups can have far more benefit to biodiversity than traditional protected area approaches.”
But mixed-species fisheries may catch dozens of species in one set of the net, and the sustainable exploitation rate may differ greatly between species. So how to harvest the most productive species and avoid the least productive ones? “Old conservation” strategies would close the areas where the most vulnerable species are typically found; the new conservation provides incentives to fishing vessels to find areas where the target species can be caught and the vulnerable species can be avoided. These latter approaches have been shown to be highly effective when applied (Branch and Hilborn 2008) and are in fact much more effective at reducing the catch of vulnerable species than closed-area strategies.
On the west coast of North America, by-catch limits for a range of species including marine birds, Pacific salmon and Pacific halibut have the potential to close highly valuable fisheries. So fishing industry groups have formed voluntary cooperatives that adopt legally binding agreements on when, where and how to fish, with the only role of government to set total catch limits (DeAlessi et al. 2014). Protected areas would never be able to achieve this kind of control as it requires day-to-day monitoring of catch and small-area closures that are not permanent.
And while protected areas seem to be an ideal solution for keeping sensitive habitats from the ravages of bottom-contact gear, the data suggest that “new conservation” may be a more effective tool for even this problem. For instance, the British Columbia continental shelf is subject to a bottom trawl fishery that tends to fish soft grounds that are not particularly sensitive. The ocean floor there is a patchwork of hard and soft areas, with corals and other sensitive structures scattered at various places along the coast. Any protected areas approach would require a highly detailed map (which does not exist) of these sensitive features and a very complex patchwork of closed areas.
What does exist, however, is an agreement negotiated between local environmental groups and the British Columbian fishing industry that includes specific closed areas; individual vessel limits on the allowable catch of corals and sponges that provide incentives for fishermen to avoid any place these might be caught; a reporting requirement to broadcast immediately any large catch of corals and sponges to the entire fleet so that these sensitive spots are identified and known; and a consultative process between government, NGOs and industry to monitor and revise these methods.
Longline hooks used to catch black cod and halibut in the Gulf of Alaska. Image credit: Nick Rahaim/Flickr through a Creative Commons license.
The protected-area approach in marine conservation has two major disadvantages. The first problem is effort displacement. When an area is closed to fishing, the vessels move elsewhere, adding fishing pressure to some areas that potentially equals or outweighs the benefits seen in the protected areas (Pastoors et al. 2000). Hamilton et al. (2010) found that abundance of target species declined outside reserves and increased inside reserves, yielding no net increase in abundance.
The second biodiversity problem is a reduction in the total sustainable yield of fish stocks when marine reserves are large. This loss will almost certainly be made up by some other form of food production with negative biodiversity consequences (Hilborn 2013). At the extreme, if lost fish production is compensated by cutting rainforest to grow crops or cattle, we can be very sure that the total biodiversity consequences will be negative.
Protection of marine biodiversity illustrates a range of ways that the new conservation working with industry groups can have far more benefit to biodiversity than traditional protected area approaches. A recent review of the implementation of by-catch reduction (Cox et al. 2007) emphasized the importance of collaboration with the fishing industry: “Three common themes to successful implementation of bycatch reduction measures are long-standing collaborations among the fishing industry, scientists, and resource managers; pre- and post-implementation monitoring; and compliance via enforcement and incentives.”
Everyone in the conservation movement is interested in protecting and ideally expanding global biodiversity. Protected areas and cooperative arrangements with extractive users are just two of a range of tools available to achieve this goal. We should focus on how best to achieve biodiversity gains and stop the pointless philosophical debates.
I thank Martin Hall and Ed Melvin for providing some of the examples and general guidance in the area of by-catch avoidance.
Branch, T. A. and R. Hilborn. 2008. Matching catches to quotas in a multispecies trawl fishery: targeting and avoidance behavior under individual transferable quotas. Canadian Journal of Fisheries and Aquatic Sciences 68:1435-1446.
California Environmental Associates. 2012. Design for Sustainable Fisheries.
Cox, T. A., R. L. Lewison, R. Zydelis, L. B. Crowder, C. Safina, and A. J. Read. 2007. Comparing effectiveness of experimental and implemented bycatch reduction measures: The ideal and the real. Conservation Biology 21:1155-1164.
DeAlessi, M., J. M. Sullivan, and R. Hilborn. 2014. The legal, regulatory, and institutional evolution of fishing cooperatives in Alaska and the West Coast of the United States. Marine Policy 43:217-225.
Finkbeiner, E. M., B. P. Wallace, J. E. Moore, R. L. Lewison, L. B. Crowder, and A. J. Read. 2011. Cumulative estimates of sea turtle bycatch and mortality in USA fisheries between 1990 and 2007. Biological Conservation 144:2719-2727.
Gutierrez, N. L., S. R. Valencia, T. A. Branch, D. J. Agnew, J. K. Baum, P. L. Bianchi, J. Cornejo-Donoso, C. Costello, O. Defeo, T. E. Essington, R. Hilborn, D. D. Hoggarth, A. E. Larsen, C. Ninnes, K. Sainsbury, R. L. Selden, S. Sistla, A. D. M. Smith, A. Stern-Pirlot, S. J. Teck, J. T. Thorson, and N. E. Williams. 2012. Eco-Label Conveys Reliable Information on Fish Stock Health to Seafood Consumers. PLOS One 7.
Hall, M. A., D. L. Alverson, and K. I. Metuzals. 2000. By-catch: Problems and solutions. Marine Pollution Bulletin 41:204-219.
Hamilton, S. L., J. E. Caselle, D. P. Malone, and M. H. Carr. 2010. Incorporating biogeography into evaluations of the Channel Islands marine reserve network. Proceedings of the National Academy of Sciences of the United States of America 107:18272-18277.
Hilborn, R. 2013. Environmental cost of conservation victories. Proceedings of the National Academy of Sciences of the United States of America 110:9187-9187.
Kareiva, P., R. Lalasz, and M. Marvier. 2011. Conservation in the anthropocene: beyond solitutude and fragility.in M. Shellenberger and T. Nordhaus, editors. Love your monster: Postenvironmentalism and the anthropocene. Breakthrough Institute.
Kareiva, P. and M. Marvier. 2012. What Is Conservation Science? BioScience 62:962-969.
Moore, J. E., B. R. Wallace, R. L. Lewison, R. Zydelis, T. M. Cox, and L. B. Crowder. 2009. A review of marine mammal, sea turtle and seabird bycatch in USA fisheries and the role of policy in shaping management. Marine Policy 33:435-451.
Pastoors, M. A., A. D. Rijnsdorp, and F. A. Van Beek. 2000. Effects of a partially closed area in the North Sea (“plaice box”) on stock development of plaice. Ices Journal of Marine Science 57:1014-1022.
Senko, J., E. R. White, S. S. Heppell, and L. R. Gerber. 2013. Comparing bycatch mitigation strategies for vulnerable marine megafauna. Animal Conservation published in early on-line May 2013 DOI: 10.1111/acv.12051.
Soule, M. E. 2013. The “New Conservation.” Conservation Biology 27:895-897.
Worm, B., H. K. Lotze, and R. A. Myers. 2003. Predator diversity hotspots in the blue ocean. Proceedings of the National Academy of Sciences of the United States of America 100:9884-9888.
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