European Parliament Public hearing on the Reform of the Common Fisheries Policy, “Ways of Securing the Future of Our Fisheries Resources”, 4 May 2011, 15.00 to 18.30
Panel 2 – Ways of Reducing or Eliminating Discards
European Parliament, Rue Wiertz 60, 1047 Brussels,Building A. SPINELLI, Room A3G-3, BELGIUM
Eric Gilman, PhD, Sustainable Fisheries Partnership and Hawaii Pacific
University, College of Natural Sciences, EGilman@FisheriesResearchGroup.org
Honorable Maria Damanaki, European Commissioner for Maritime Affairs and Fisheries, Carmen Fraga Estevez, Chair of the Committee on Fisheries, Vasilios Mylonas who kindly invited me to provide testimony to you today, Honorable Members of the European Parliament, fellow panelists, thank you for this opportunity to discuss alternative approaches to govern discards under the Common Fisheries Policy.
Governance of Discards to Achieve Ecosystem Maintenance via the European Union Common Fisheries Policy
1. Adverse Effects from Discarding
Overexploitation in marine fisheries, including from discard fishing mortality, is currently the largest driver of change and loss in global marine biodiversity, causing complex changes, from genetic diversity to ecosystem integrity, threatening to reach tipping points where irreversible regime shifts occur (Pauly et al. 2005; Pereira et al. 2010). Responsible fisheries conduct requires effective governance of all sources of fishing mortality, including from retained target catch, retained and discarded bycatch, and unobserved mortalities (United Nations 1982, 1995; Hall et al. 2000; FAO 1995, 2003 2010b,c; Gilman 2011). An integral component of implementing the ecosystem approach to fisheries, this is necessary to contribute to maintaining marine biodiversity, ecosystem structure and functioning, and is necessary to avoid negative socioeconomic consequences for fishing communities (Hall et al. 2000; FAO 2003, 2008, 2010c). Overarching goals are to prevent the overexploitation of all populations and stocks subject to fishing mortality per se, including species and sizes subject to discarding, and also to avoid and minimize adverse effects from all fishery removals, including discard fishing mortality, on ecosystem structure, processes, and services, including fishery resources.
Discarded catch, along with offal from processing fish at sea, and discarded and lost bait, raise an ecological concern due to changes in the foraging behavior, diet, and competitiveness of coastal and marine species, for instance, by scavenging seabirds, marine mammals, sharks, and benthic scavengers; changes to the food web and distribution of biomass within an ecosystem; and in fisheries where discards are spatially concentrated, may also cause localized anoxia of the seabed (Blaber et al. 1995; Goñi 1998; Groenewold and Fonds 2000; Hall et al. 2000; Stevens et al. 2000; FAO 2003; Gilman et al. 2006a; Furness et al. 2007; Franco et al. 2008). Furthermore, discarded bycatch raises a social issue over waste, representing a threat to the long-term capacity to provide food and a source of livelihood (Clucas 1997; Harrington et al. 2005; Kelleher 2005; FAO 2010a). Unsustainable levels of discarded and retained bycatch also have concomitant negative socioeconomic consequences for fishing communities (FAO 2008). Overexploitation of commercially important incidental species, including bycatch of juveniles of a commercial species, can cause growth and recruitment overfishing, leading to a decline in future catch levels, and result in allocation issues between fisheries (Hall et al. 2000; Langley et al. 2009; Sumaila and Bailey 2011). Minimizing fisheries waste (i.e., discarded catch that is fit for human consumption or that is used as feed for aquaculture or animal industries) is mainly a socioeconomic issue, although developing markets for currently discarded catch with concomitant increased retention could reduce fishing mortality of overexploited stocks.
2. Why Discarding Occurs
Fishers may discard catch due to market/economic considerations, such as discarding species and sizes lacking markets, with no or relatively low value, damaged catch with low or no value, species that are incompatible with the rest of the catch during storage (e.g., sharks, which concentrate urea in their blood which is converted by bacteria to ammonia, can contaminate other species in the hold), and high-grading involving discarding lower-value catch to make room in the hold for higher value catch, when room in the hold is a limiting factor, and the perceived difference in net value between discarded and retained fish is greater than the cost to replace the discard (Arnason 1994; Alverson et al. 1994; Hall 1996; Vestergaard 1996; Kelleher 2005). Quality, including catch that is unfit for human consumption due to spoilage or toxicity, provides another reason to discard part of the catch. Furthermore, output controls create incentives for discarding: Quota induced high-grading occurs when a vessel reaches a species-based quota, and discards lower value grades to enable retaining higher value grades; over quota discarding occurs in multispecies fisheries when a quota for one species is reached, but quotas for other species are not in place or have not been reached, and the vessel discards additional catch of the species for which the quota has been reached; discarding sublegal individuals can occur to comply with measures for species-based minimum landing sizes; discarding may be conducted in order to meet prescribed catch composition (measures setting limits on the percent catch composition by species); and discarding may be conducted to comply with restrictions on retention by sex (e.g., crabs) (Anderson 1994; Arnason 1994; Alverson et al. 1994; Hall 1996; Kelleher 2005; Defra 2006; Coggins et al. 2007; Graham et al. 2007; Poos et al. 2010).
From 1992-2001, an average of 7.3 million tonnes of fish were annually discarded, representing 8% of the world catch (Kelleher 2005). There have been substantial reductions in discard levels in recent years, in part, due to increased retention as a result of the development of markets for previously discarded species and sizes, but also from increased gear selectivity reducing catch rates of unmarketable catch (Pascoe 1997; Kelleher 2005; Gilman 2011).
3. Achieving Sustainable Discard Practices
Achieving ecologically and socioeconomically sustainable discard practices is not necessarily achieved via increasing fishing selectivity. Selective fishing and gear, by concentrating fishing mortality on a narrow subset of an ecosystem’s components, can cause ecological and evolutionary change and loss, reduce ecosystem stability and alter ecosystem function and structure, with effects on ecosystems services including reduced fisheries productivity (Conover and Munch 2002; Bundy et al. 2005; Frid et al. 2006; Rochet et al. 2009; Zhou et al. 2010). Selectively removing certain trophic levels, species, stocks, populations, sizes, and sexes alters their relative abundance within an ecosystem, resulting in ecological effects such as trophic cascades, and changes in predation pressure, with concomitant altered ecosystem structure and function (Ulanowicz and Puccia 1990; Casey and Meyers 1998; Stevens et al. 2000; Daskalov 2002; Pauly et al. 1998, 2002; Bundy et al. 2005; Frid et al. 2006; Bakun et al. 2009; Garcia et al. 2011). Selective fishing can reduce genetic diversity by removing specific sizes, age classes, and/or sexes of a population, stock and species (Frid et al. 2006; Heino and Deickmann 2008; Zhou et al. 2010). Increasingly recognized as cause for concern, as a result of fishing gear selecting for large individuals, due to market forces or management measures, marine capture fishing has altered the distribution of fish sizes; favored genotypes for maturation at an earlier age (in particular for fish species with relatively late maturation), smaller size, and slower growth; reduced the proportion of large, fast-growing individuals; reduced the fecundity, duration of the spawning season, as well as survival potential, size and growth rates of larvae, causing reduced reproductive potential and potential for recovery from overexploitation (Heino 1998; Law 2000; Stevens et al. 2000; Heino and Godo 2002; Pauly et al. 2002; Berkeley et al. 2004; Ernande et al. 2004; Birkeland and Dayton 2005; Swain et al. 2007; Fenberg and Roy 2008; Heino and Deickmann 2008; Zhou et al. 2010). This may have caused irreversible changes in the gene pool, altering the evolutionary characteristics of exploited populations and species (Law 2000; Stevens et al. 2000; Pauly et al. 2002; Swain et al. 2007; Fenberg and Roy 2008; Zhou et al. 2010). Counter to international guidance, distributing fishing mortality, including from discards, equivalently across facets of biodiversity, with sustainable fishing exploitation rates that are in proportion with species’, populations’, stocks’, and trophic level’s intrinsic capacity, is more likely to minimize change and loss across manifestations of marine biodiversity, including maintaining the integrity of trophic structure, species richness, and ecosystem structure and functioning, and sustaining ecosystem services – with predicted increased fisheries production (Hall 1996; Bundy et al. 2005; Fenberg and Roy 2008; Zhou et al. 2010; Garcia et al. 2011). Depending on the individual fishery, achieving this objective might require increasing mortality of non-targets, including species and sizes that are currently subject to discarding. This recommended paradigm shift from selective to ‘diluted’ fishing and gears has been proposed for at least 15 years (Hall 1996), and while there has been recent international attention (Garcia et al. 2011), selectivity remains the entrenched prevailing governance approach. Effective implementation of diluted non-selective fishing mortality will require five components:
· Eliminate the selective removal of larger species and individuals within populations, and replace this with fisheries and gears that result in the preservation of community structure and size-frequency distributions of species characteristic of unexploited conditions, accomplished by distributing fishing mortality across marine ecosystem components (communities within an ecosystem, time period, area, trophic level, assemblage, species, stock, population, and size, age class and sex within a population) at sustainable levels according to natural production capacities (Conover and Munch 2002; Birkeland and Dayton 2005; Fenberg and Roy 2008).
· Develop or augment markets for currently non-utilized or underutilized species, sizes, and sexes (e.g., Clucas 1997) so as to create demand for their supply at sustainable mortality rates, and address the logistics for handling and processing the mixture of species and sizes for these products (Hall et al. 2000).
· Reduce fishing mortality of species - to - intra-population components that are overexploited – in line with keeping fishing mortality rates commensurate with a species/stocks/population’s abundance and population growth.
· Continue selectivity to effectively mitigate bycatch of vulnerable (rare, endemic and threatened) species (e.g., sea turtles, seabirds, sharks, marine mammals), species critical for regulating ecosystem structure and processes (keystone and foundation species), and phylogenetically distinct species (Caro and O’Doherty 1999; Ellison et al. 2005; Redding and Moores 2006; Jordan 2009).
· Establish ecosystem-level ecological indicators, reference points and control rules to enable effective implementation of ecosystem-based fisheries management (Pikitch et al. 2004; Bundy et al. 2005), and monitor trends in abundance of species most vulnerable to fishing (Branch et al. 2010).
4. Fishery-Specific Considerations of Alternative Discard Control Measures
Several countries and regional
fisheries management organizations have adopted measures that prohibit
discarding at sea (e.g., Hampton 2003; Peacey 2003; Graham et al. 2007; IATTC
2009; WCPFC 2009; NEAFC 2010; Iceland Ministry of Fisheries 2011). Ecological and socioeconomic effects from
requiring full retention are fishery-specific, and therefore warrant
fishery-specific assessment. In some
fisheries, banning discards could have a positive effect by creating a strong
incentive for fishermen to voluntarily employ effective gear designs and
fishing methods to avoid the capture of unmarketable species and sizes of fish
and, and eliminating high-grading (Gillis et al. 1995; Graham et al.
2007). For instance, various gear
technology approaches can effectively reduce unwanted catches, as can avoiding
temporally and spatially predictable hotspots of unwanted catches (Hall et al.
2000; Poos et al. 2010; Gilman et al. 2006c, 2009; Dunn et al. 2011; Gilman
2011). Full retention may, however, be
an ineffective mechanism to deter catch and reduce fishing mortality in some
fisheries. For example, in fisheries
where non-target species and sizes of fish are close in value to the target
species, a discard ban would provide low incentive for fishers to take measures
to reduce their catch of these non-target species and sizes (e.g.,
juvenile/small bigeye tuna in purse seine fisheries, Gilman 2011). Measures have been adopted to address this
issue: in Norway, a discard ban of fish
below a minimum size is in place, and landed undersized fish are sold through
sales organizations, but the revenue from the sales do not go to the fisheries,
avoiding an incentive to catch small fish (Hall and Mainprize 2005; Graham et
al. 2007), a measure that requires 100% onboard observer coverage to ensure
compliance. Similarly, in Iceland, fish
that are required to be retained and landed result in a quota reduction of 50%
of the landed weight of the fish subject to a discard ban, and in New Zealand,
fishers receive half of the value of the fish subject to a discard ban
(Elliston et al. 2005; Hall and Mainprize 2005). Consideration is also warranted regarding
whether required full retention might create markets for species that are
relatively vulnerable to overexploitation and/or have a disproportionate
role in regulating and maintaining ecosystem function or structure, leading to
increased and potentially unsustainable fishing mortality rates.
In some fisheries, in combination with measures aimed to minimize rates
of bycatch of vulnerable species, measures to maximize post-release survival
rates of vulnerable stocks might be more likely to fulfill an aim of reducing
fishing mortality of these stocks than would be a requirement for their full
retention: Banning discards may be
detrimental for species groups that have even a small post-release survival
rate. This requires fishery-specific
consideration, as survival rates of discards are highly variable between
species groups (e.g., Chopin and Arimoto 1995; Laptikhovsky 2004; Suuronen
2005). For overexploited stocks, if
evidence suggests that a high rate of survival occurs, then prohibiting
retention of these species in combination with best practice handling and
release practices, would contribute to stock rebuilding, where required full
retention might not reduce fishing mortality of these stocks. Efficacy of a discard ban requires fishing
industry ownership of the measure to achieve high compliance, flexibility in
output controls to reduce incentives for discarding, or otherwise, extensive
resources for surveillance and enforcement (Baulch
and Pascoe 1992; Turner 1996; Kaufamann et al. 1999; Arnason 2002; Hall
et al. 2000; Peacey 2003; Poos et al. 2010).
Otherwise, a discard ban might result in reduced reporting of discards,
resulting in errors in stock assessments and scientific advice, and increase
the probability of exceeding reference points (Pascoe 1997; Crowder and
Murawski 1998; Poos et al. 2010). Furthermore, if prescribed
full retention applies to non-principal market species, and resources for
surveillance and enforcement are sufficient, retained unwanted bycatch may be
dumped following landing, unless markets for currently non-utilized or
underutilized species, sizes, and sexes are developed to create demand for
their supply at sustainable mortality rates, and logistics for handling and
processing the mixture of species and sizes for these products are addressed,
retained unwanted bycatch may be dumped following landing (Clucas, 1997; FAO,
1997; Hall et al., 2000; Kelleher, 2005).
5. Minimum Framework for the Governance of Discarded Catch
Data collection protocols, onboard observer coverage, ecological risk assessment, binding control measures, surveillance, and enforcement comprise fundamental, minimum requirements for effective governance of discards in marine capture fisheries. A deficit in one or more of these governance framework components is likely to compromise the ability to achieve ecologically sustainable fisheries (Gilman 2011).
· Discard data collection protocols: In general, basic information needed to understand discards includes: quantity, weight, species, age classes, length frequency, disposition when released, and date and location caught. Dataset quality is improved through employment of standardized data collection methods and dataset formatting to enable interoperability and pooling of datasets. A longer time series, and balanced observations temporally and spatially across a fisheries’ grounds, augment the range of supported scientific applications (Pitcher and Preikshot 2001; Kelleher 2005; Gilman et al. 2008a,b; Gilman 2011).
· Onboard observer coverage rates: Observer data are vital to identifying and understanding any trends in discard rates and levels, and in assessing performance of control measures in a commercial setting, where methods for the employment of prescribed bycatch mitigation methods are known to differ from experimental conditions (Cox et al. 2007; Gilman et al. 2005, 2008b). Adequate data collection protocols and observer coverage rates are needed to allow for robust statistical analyses of discards, including documentation of discard rates, fleet-wide extrapolations, and identification of when, where, and why discarding occurs. The objectives of analyses (i.e., required levels of accuracy and precision), the rate of discarding, amount of fishing effort, and distribution of discard catch determine the requisite onboard observer coverage rate (Hall 1999; McCracken 2005; Gilman 2011).
· Ecological risk assessment: Fishery-specific assessments should be conducted to enable an understanding of the effect of fishing mortality on discard species and to enable an understanding of broader effects of bycatch across facets of biodiversity (i.e., how does bycatch fishing mortality and discards affect marine biodiversity, from genetic diversity to ecosystem integrity) (Bjorndal et al. 2011; Gilman 2011). Ecological risk assessment of the effects of fishing can be undertaken employing a hierarchical approach with three levels along a continuum from a qualitative first order to quantitative rigorous assessment (Hobday et al. 2007; Kirby 2006; Sainsbury and Sumaila 2001). Ecological risk assessments have focused on assessing effects of fisheries on vulnerable species, including bycatch of seabirds, sea turtles, marine mammals and elasmobranchs (Gilman 2011) and have not augmented knowledge of broader effects of bycatch across facets of biodiversity, ranging from reducing genetic diversity of populations subject to bycatch fishing mortality to altering ecosystem regulation or structure due to overexploitation of a bycatch species that is a keystone or foundation species, respectively.
· Control measures to mitigate problematic discards: Legally binding measures, with measurable/quantitative performance standards, are required to mitigate problematic discarding identified through comprehensive ecological risk assessments (Gilman 2011). Combinations of control measures can effectively reduce incentives for discarding (Section 4). Additionally, measures may be needed to mitigate pollution resulting from discarding, in general, where fishing grounds occur in areas where adverse pollution effects from the discharge of discarded catch, offal from processed catch, and spent bait are likely to result, fisheries are understood to have relatively large levels of discharges, and discharges during fishing operations are spatially concentrated.
· Surveillance and enforcement: Adequate surveillance and enforcement mechanisms are needed so that (i) surveillance activities enable assessment of compliance of discards control measures; (ii) enforcement procedures are transparent and effective; (iii) penalties/sanctions for detected infringements provide a large incentive for fisher compliance with binding measures; and (iv) transparent reporting on enforcement activities and conclusions enable confidence that discard measures have high compliance with effective enforcement of infractions.
Alverson, D.L., Freeberg, M.H., Murawski, S.A. and Pope, J.G. (1994) A Global Assessment of Fisheries Bycatch and Discards. Fisheries Technical Paper No. 339. Rome, Italy: Food and Agriculture Organization of the United Nations.
Anderson, L. (1994) An economic analysis of highgrading in ITQ fisheries regulation programs. Marine Resource Economics 9, 209–26.
Arnason, R. (1994) On catch discarding in fisheries. Marine Resource Economics 9, 189-207.
Arnason, R. (2002) A Review of International Experiences with ITQs: Annex to Future Options for UK Fish Quota Management, CEMARE Report 58. CEMARE, Portsmouth, United Kingdom.
Bakun, A., Babcock, E., and Santora, C. (2009) Regulating a complex adaptive system via its wasp-waist: grappling with ecosystem-based management of the New England herring fishery. ICES Journal of Marine Science 66, 1768-1775.
Baulch, K. and Pascoe, S. (1992) Bycatch Management Options in the South East Trawl Fishery, ABARE Research Report 92.18. Australian Bureau of Agricultural and Resource Economics, Canberra.
Berkeley, S., Chapman, C., and Sogard, S. (2004) Maternal age as a determinant of larval growth and survival in a marine fish, Sebastes melanops. Ecology 85, 1258–1264.
Birkeland, C., and Dayton, P. (2005) The importance in fishery management of leaving the big ones. Trends in Ecology and Evolution 20, 356-358.
Bjorndal, K., Bowen, B., Chaloupka, M. et al. (2011) Better science needed for restoration in the Gulf of Mexico. Science 331, 537-8.
Blaber, S., Milton, D., Smith, G., and Farmer, M. (1995) The importance of trawl discards in the diets of tropical seabirds of the northern Great Barrier Reef, Australia. Marine Ecology Progress Series. 127, 1-13.
Branch, T., Watson, R., Fulton, E. et al. (2010) The trophic fingerprint of marine fisheries. Nature 468, 431-435.
Bundy, A., Fanning, P. and Zwanenburg, K. (2005) Balancing exploitation and conservation of the eastern Scotian Shelf ecosystem: application of a 4D Ecosystem exploitation index. ICES Journal of Marine Science 65, 503-510.
Caro, T, and O'Doherty, G. (1999) On the use of surrogate species in conservation biology. Conservation Biology 13, 805-814.
Casey, J., and Myers, R. (1998) Near extinction of a large, widely distributed fish. Science 281, 690–692.
Catchpole, T., and Gray, T. (2010) Reducing discards of fish at sea: a review of European pilot projects. Journal of Environmental Management 91, 717-723.
Chopin, F., and Arimoto, T. (1995) The condition of fish escaping from fish gears – a review. Fisheries Research 21, 315–327.
Clucas, I. (1997) A Study of the Options for Utilization of Bycatch and Discards from Marine Capture Fisheries. FAO Fisheries Circular No. 928. Food and Agriculture Organization, Rome.
Coggins, L., Catalano, M., Allen, M., Pine, W., and Walters, J. (2007) Effects of cryptic mortality and the hidden costs of using length limits in fishery management. Fish and Fisheries 8, 196–210.
Conover, D., and Munch, S. (2002) Sustaining fisheries yields over evolutionary time scales. Science 297, 94–96.
Cox, T.M., Lewison, R.L., Zydelis, R., Crowder, L., Safina, C., and Read, J. (2007) Comparing effectiveness of experimental and implemented bycatch reduction measures: The ideal and the real. Conservation Biology 21, 1155-1164.
Crowder, L., and Murawski, S. (1998) Fisheries bycatch: Implications for management. Fisheries 23, 8-17.
Daskalov, G. M. (2002) Overfishing drives a trophic cascade in the Black Sea. Marine Ecology Progress Series 225, 53–63.
Defra. (2006) Discards. Stakeholder Forum meeting 21 September 2006. Item 4 Paper 2. Department for Environment, Food and Rural Affairs, Sea Fisheries Conservation Division, London, UK.
Dunn, D., Boustany, A., and Halpin, P. (2011) Spatio-temporal management of fisheries to reduce by-catch and increase fishing selectivity. Fish and Fisheries 12, DOI: 10.1111/j.1467-2979.2010.00388.x.
Ellison, A., Bank, M., Clinton, B. et al. (2005) Loss of foundation species: consequences for the structure and dynamics of forested ecosystems. Frontiers in Ecology and the Environment 3, 479-486.
Elliston, L., Kompas, T. and Bosch, C. (2005) Discarding of Commercial Catch: Implications for Commonwealth Fisheries Managed with ITQs, ABARE eReport 05.8. Australian Bureau of Agricultural and Resource Economics, Canberra.
Ernande, B., Dieckmann, U., and Heino, M. (2004) Adaptive changes in harvested populations: plasticity and evolution of age and size at maturation. Proceedings of the Royal Society B: Biological Sciences 271, 415-423.
Estrada, E. (2007) Characterisation of topological keystone species: local, global and “meso-scale” centralities in food webs. Ecological Complexity 4, 48–57.
FAO. (1995) Code of Conduct for Responsible Fisheries. Food and Agriculture Organization of the United Nations, Rome.
FAO. (2003) The Ecosystem Approach to Fisheries. FAO Technical Guidelines for Responsible Fisheries, No. 4 (Suppl. 2). Food and Agriculture Organization of the United Nations, Rome.
FAO. (2008) Towards Integrated Assessment and Advice in Small-Scale Fisheries: Principles and Processes. FAO Fisheries and Aquaculture Technical Paper No. 515. Food and Agriculture Organisation of the United Nations, Rome.
FAO. (2010a) The State of World Fisheries and Aquaculture 2010. ISBN 978-92-5-106675-1. Food and Agriculture Organization of the United Nations, Rome.
FAO. (2010b) Technical Consultation to Develop International Guidelines on Bycatch Management and Reduction of Discards. Rome, Italy, 6-10 December 2010. Secretariat Working Paper. TC-BM/2010/2. Food and Agriculture Organization of the United Nations, Rome.
FAO. (2010c) Report of the Expert Consultation on International Guidelines for Bycatch Management and Reduction of Discards. Rome, 30 November – 3 December 2009. FAO Fisheries and Aquaculture Report No. 934. Food and Agriculture Organization of the United Nations, Rome.
Fenberg, P., and Roy, K. (2008) Ecological and evolutionary consequences of size-selective harvesting: how much do we know? Molecular Ecology 17, 209–220.
Franco, M., Steyaert, M., Cabral, H. et al. (2008) Impacts of discards of beam trawl fishing on the nematode community from the Tagus estuary (Portugal). Marine Pollution Bulletin 56, 1728-1736.
Frid, C.; Paramor, O., and Scott, C. (2006) Ecosystem-based management of fisheries: is science limiting? ICES Journal of Marine Science 63, 1567-1572.
Furness, R., Edwards, A., and Oro, D. (2007) Influence of management practices and of scavenging seabirds on availability of fisheries discards to benthic scavengers. Marine Ecology Progress Series 350, 235-244.
Garcia, S. (Ed.), Kolding, J., Rice, J., et al. (2011) Selective Fishing and Balanced Harvest in Relation to Fisheries and Ecosystem Sustainability. International Union for the Conservation of Nature and European Bureau for Conservation and Development, Gland, Switzerland and Brussels, Belgium.
Gillis, D., Pikitch, E., and Peterman, R. (1995) Dynamic discarding decisions: foraging theory for high-grading in a trawl fishery. Behavioral Ecology 6, 146-154.
Gilman, E. (2011) Bycatch governance and best practice mitigation technology in global tuna fisheries. Marine Policy doi:10.1016/j.marpol.2011.01.021.
Gilman, E., Brothers, N., and Kobayashi, D. (2005) Principles and approaches to abate seabird bycatch in longline fisheries. Fish and Fisheries 6, 35-49.
Gilman, E., Brothers, N., McPherson, G., and Dalzell, P. (2006a) Review of cetacean interactions with longline gear. Journal of Cetacean Research and Management 8, 215-223.
Gilman, E., Clarke, S., Brothers, N. et al. (2008a) Shark interactions in pelagic longline fisheries. Marine Policy 32, 1-18.
Gilman, E., Dalzell, P., and Martin, S. (2006c) Fleet communication to abate fisheries bycatch. Marine Policy 30, 360-366.
Gilman, E, Gearhart, J., Price, B. et al. (2009) Mitigating sea turtle bycatch in coastal passive net fisheries. Fish and Fisheries 11, 57-88.
Gilman, E., Kobayashi, D., and Chaloupka, M. (2008b) Reducing seabird bycatch in the Hawaii longline tuna fishery. Endangered Species Research 5, 309-323.
Goñi, R. (1998) Ecosystem effects of marine fisheries: an overview. Ocean and Coastal Management 40, 37-64
Graham, N., Ferro, R., Karp, W., and MacMullen, P. (2007) Fishing practice, gear design, and the ecosystem approach—three case studies demonstrating the effect of management strategy on gear selectivity and discards. ICES Journal of Marine Science 64, 744–750.
Groenewold, S., and Fonds, M. (2000) Effects on benthic scavengers of discards and damaged benthos produced by the beam-trawl fishery in the southern North Sea. ICES Journal of Marine Science 57, 1395-1406.
Hall, M.A. (1996) On bycatches. Reviews in Fish Biology and Fisheries 6, 319-352.
Hall, M.(1999) Estimating the ecological impacts of fisheries: What data are needed to estimate bycatches? Pp.175-184 IN Nolan, C. (ed.). Proceedings of the International Conference on Integrated Fisheries Monitoring. Sydney, Australia, 1-5 February 1999. Food and Agriculture Organization of the United Nations, Rome.
Hall, M.A., Alverson, D.L. and Metuzals, K.I. (2000) By-catch: problems and solutions. Marine Pollution Bulletin 41, 204-219.
Hall, S., and Mainprize, B. (2005) Managing by-catch and discards: how much progress are we making and how can we do better? Fish and Fisheries 6, 134-155.
Hampton, I. (2003) Harvesting the sea. PP. 31-69 IN Molloy, F. Reinikainen, T. (Eds.). Namibia’s Marine Environment. Namibia Directorate of Environmental Affairs of the Ministry of Environment and Tourism, Windhoek, Namibia.
Harrington, J., Myers, R.A., and Rosenbery, A. (2005) Wasted fishery resources: Discarded by-catch in the USA. Fish and Fisheries 6, 350–361.
Heino, M. (1998) Management of evolving fish stocks. Canadian Journal of Fisheries and Aquatic Sciences 55, 1971-1982.
Heino, M., and Dieckmann, U. (2008) Detecting fisheries-induced life-history evolution: an overview of the reaction norm approach. Bulletin of Marine Science 83, 69-93.
Heino, M., and Godo, O. (2002) Fisheries-induced selection pressures in the context of sustainable fisheries. Bulletin of Marine Science 70, 639–656.
Hobday, A., Smith, A., Webb, H. et al. (2007) Ecological Risk Assessment for the Effects of Fishing: Methodology. Report R04/1072. Australian Fisheries Management Authority, Canberra, 174 pp.
IATTC. (2009) Resolution on a Multiannual Program for the Conservation of Tuna in the Eastern Pacific Ocean in 2009-2011. Resolution C-09-01. Inter-American Tropical Tuna Commission, La Jolla, USA.
Iceland Ministry of Fisheries. (2011) Icelandic Fisheries Management. http://en.fiskistofa.is/cntPage.php?pID=4 accessed 9 March 2011.
Jordan, F. (2009) Keystone species and food webs. Philosophical Transactions of the Royal Society B. 364, 1733-1741.
Kaufmann, B., Geen, G. and Sen, S. (1999) Fish Futures: Individual Transferable Quotas in Fisheries. Fisheries Research and Development Corporation, Kiama, New South Wales.
Kelleher, K. (2005) Discarding in the World’s Marine Fisheries: An Update. Food and Agriculture Organization of the United Nations. FAO Fisheries Technical Paper No. 470. Rome.
Kirby, D. (2006) Ecological Risk Assessment for Species Caught in WCPO Tuna Fisheries: Inherent Risk as Determined by Productivity-Susceptibility Analysis. WCPFC-SC2-2006/EB WP-1.
Langley, A., Wright, A., Hurry, G., Hampton, J., Aqorua, T., and Rodwell, L. (2009) Slow steps towards management of the world’s largest tuna fishery. Marine Policy 33, 271-279.
Laptikhovsky, V. (2004) Survival rates for rays discarded by the bottom trawl squid fishery off the Falkland Islands. Fisheries Bulletin (Wash DC) 102, 757-759.
Law, R. (2000) Fishing, selection, and phenotypic evolution. ICES Journal of Marine Science 57, 659–668.
McCracken, M. (2005) Modeling a Very Rare Event to Estimate Sea Turtle Bycatch: Lessons Learned. NOAA Tech. Memo. NOAA-TM-NMFS-PIFSC-3. National Marine Fisheries Service, Pacific Islands Fisheries Science Center, Honolulu.
NEAFC. (2010) Recommendation by the North-East Atlantic Fisheries Commission in Accordance with Article 5 of the Convention on Future Multilateral Cooperation in North-East Atlantic Fisheries at its Annual Meeting in November 2009 for a Ban on Discards in the NEAFC Regulatory Area. Recommendation XVI: 2010. North East Atlantic Fisheries Commission, London.
Pascoe, S. (1997) Bycatch Management and the Economics of Discarding, FAO Fisheries Technical Paper, no. 370. Food and Agriculture Organization of the United Nations, Rome.
Pauly, D., Christensen, V., Dalsgaard, J., Froese, R. and Torres, F. Jr. (1998) Fishing down marine food webs. Science 279, 860–863.
Pauly, D., Christensen, V., Guenette, S. et al. (2002) Towards sustainability in world fisheries. Nature 418, 689-695.
Pauly, D., Alder, J., Bakun, A. et al. (2005) Chapter 18. Marine Fisheries Systems. PP. 477 – 511 IN Ecosystems and Human Well-Being: Current State and Trends. Findings of the Condition and Trends Working Group. Millennium Ecosystem Assessment. Series Vol. 1. Washington, D.C., Island Press.
Peacey, J. (2003) Managing Catch Limits in Multispecies ITQ Fisheries, New Zealand Ministry of Fisheries, Wellington.
Pereira, H., Leadley, P., Proença, V. et al. (2010) Scenarios for global biodiversity in the 21st century. Science DOI:10.1126/science.1196624.
Pikitch, E. K., Santora, C., Babcock, E. A. et al. (2004) Ecosystem-based fishery management. Science 305, 346e347.
Pitcher, T.J., and Preikshot, D. (2001) RAPFISH: A rapid appraisal technique to evaluate the sustainability status of fisheries. Fisheries Research 49, 255-270.
Poos, J., Bogaards, A., Quirijns, F., and Rijnsdorp, A. (2010) Individual quotas, fishing effort allocation, and over-quota discarding in mixed fisheries. ICES Journal of Marine Science 67, 323-333.
Redding, D. and Moores, A. (2006) Incorporating evolutionary measures into conservation prioritization. Conservation Biology 20, 1670-1678.
Rochet, M., Benoît, E. and Collie, J. (2009) Is selective fishing more harmful to marine communities than even exploitation? Theoretical investigations. ICES CM 2009/M: 07.
Sainsbury, K. and Sumaila, U. (2001) Incorporating Ecosystem Objectives into Management of Sustainable Marine Fisheries, Including Best Practice Reference Points and Use of Marine Protected Areas. Reykjavik Conference on Responsible Fisheries in the Marine Ecosystem, Reykjavik Iceland, 1-4 October 2001.
Stevens, J., Bonfil, R., Dulvy, N. and Walker, P. (2000) The effects of fishing on sharks, rays, and chimaeras (chondrichthyans), and the implications for marine ecosystems. ICES Journal of Marine Science 57(3), 476-494.
Sumaila, U.R. and Bailey, M. (2011) Sequential game theoretic models of western central Pacific tuna stocks. IN Gilman, E., Ishizaki, A., Chang, D., Liu, W.Y. and Dalzell, P. (Editors). Proceedings of the Fifth International Fishers Forum on Marine Spatial Planning and Bycatch Mitigation. Western Pacific Regional Fishery Management Council, Honolulu, USA. ISBN 1-934061-54-9.
Suuronen, P. (2005) Mortality of Fish Escaping Trawl Gears. FAO Fisheries Technical Paper, 478. Food and Agriculture Organization of the United Nations, Rome.
Swain, D.P., Sinclair, A.F. and Hanson, J. (2007) Evolutionary response to size-selective mortality in an exploited fish population. Proceedings of the Royal Society of London B: Biological Sciences 274,1015–1022.
Turner, M. (1996) Value based ITQs. Marine Resource Economics 11(2), 59–69.
Ulanowicz, R. and Puccia, C. (1990) Mixed trophic impacts in ecosystems. Coenoses 5, 7–16.
United Nations. (1982) The United Nations Convention on the Law of the Sea. United Nations, New York.
United Nations. (1995) Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10 December 1982, Relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks. UN General Assembly, Doc. A/CONF.164/37, September 8, 1995, 36 pp.
Vestergaard, N. (1996) Discard behavior, highgrading and regulation: The case of the Greenland shrimp fishery. Marine Resource Economics 11, 247-266.
WCPFC. (2009) Conservation and Management Measure on the Application of High Seas FAD Closures and Catch Retention. CMM 2009-02. Western and Central Pacific Fisheries Commission, Palikir, Federated States of Micronesia.
Zhou, S., Smith, A., Punt, A. et al. (2010) Ecosystem-based fisheries management requires a change to the selective fishing philosophy. Proceedings of the National Academy of Sciences 107, 9485-9489.
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