Recovery Planning for Marine Turtles in Australia: Benefits of a Approach
Armstrong, Julie Robins, Katrina Maguire
All marine turtles that occur in Australia are listed on Schedule 1 of the Australian Endangered Species Protection Act 1992 as either endangered or vulnerable. A variety of anthropomorphic and other impacts (e.g habitat change, fox predation) are threatening the viability of marine turtle populations, with the relative importance of each impact djffering for each of the six species of marine turtle that occur in Australian waters. Australian endangered species legislation provides four mechanisms for dealing with population declines of listed species. Two of these are recovery plans or threat abatement plans. The merits of each of these two mechanisms in assisting in the conservation of marine turtks are examined in this paper.
The capture and drowning of marine turtks in otter trawls is one of the notable, but manageable, threats to some Australian turtle populations. Fisheries action and management plans have been designed to mitigate marine turtle bycatch, and substantial progress has been made towards resolving the issue. Timetables for implementing the use of turtle excluder devices have been established although negotiations about the extent and timing of TED use continue in one fishery.
This paper argues that threats to marine turtles in Australia can be more thoroughly addressed through a coordinated national recovery plan that mitigates and manages all threats, rather than through an identification of key threatening processes and their related threat abatement plan. This latter approach has the limitation of only dealing with the particular threat that is listed The national turtk recovery plan provides scope for a holistic approach to marine turtle conservation, that encompasses a wide range of interests and all identified threats, and determines appropriate actions for the resolution of the issues.
All six species of marine turtle found in Australian waters are listed under the Endangered Species Protection Act 1992 (ESPA) (Table I). The Act provides four mechanisms that can be applied to address declines in populations numbers of species listed under the Act. Two such mechanisms are recovery plans and threat abatement plans. The other two, conservation agreements and conservation orders will not be discussed in this paper.
There are fundamental differences in the approaches adopted in preparing recovery plans and threat abatement plans. All endangered and vulnerable species listed under the ESPA must have a recovery plan prepared and implemented. The plan must contain at least the following four critical elements:
i) an objective to be achieved over the life of the plan;
ii) criteria against which the objective is measured;
iii) a budget and timetable for actions needed to satisfy the criteria; and
iv) actions to protect critical habitat (Male 1996).
Table I: Status of marine turtles under the Endangered Species Protection Act 1992.
A threat abatement plan must be developed and implemented if a specific threat or activity is listed as a "key threatening process' to species listed as endangered or vulnerable under the ESPA. A threat is eligible to be nominated as a key threatening process under Schedule 3 (S23) of the ESPA if a) it adversely affects two or more listed native species or two or more listed ecological communities; or could cause native species or ecological communities that are not endangered to become endangered; and b) the preparation and implementation of a nationally coordinated threat abatement plan is a feasible, effective and efficient way to abate the process. The guidelines under which an activity can be nominated as a key threatening process are broad. Nominations can be received from any member of the public, association or government agency but a qualified and independent expert panel must formally assess them.
Both mechanisms provided by the ESPA seek to achieve the best outcome for mitigating impacts on endangered or vulnerable species and assisting populations that have declined to recover. Threat abatement planning that results from the listing of an activity as a key threatening process often occurs in an atmosphere charged with blame, accusation and confrontation. This is not always in the best interest of the species because threat abatement plans usually require the cooperation of those identified as responsible for the environmental damage. For example, the change brought about through threat abatement planning for the impacts of longline fishing on seabirds has been fought out publicly on television' in industry journals and in newspapers. It has been politicised and opposed by sectors of the industry but fortunately not through litigation. Most would agree that such a situation makes it harder to achieve good negotiated outcomes. One of the key findings in this process is the need to understand and respect the economic and social costs of decisions associated with implementing threat abatement plans.
The nomination of a key threatening process provides a means for community and non-government organisations to raise the profile of particular activities. The threat of nomination (as opposed to declaration) is normally enough to trigger responses from management agencies and other interested parties because a successful nomination is perceived to have the potential of imposing new regulations and costs on industries and regulatory agencies. Environment Australia has legislative responsibility to prepare a threat abatement plan if a threat is listed as a key threatening process.
Marine turtles in Australia are the subject of a draft national recovery plan that is due to be finalised in September 1999. They have also been scrutinised as affected species in the nomination of otter trawling as a key threatening process. The evolution of the national recovery plan for marine turtles and the potential for a threat abatement plan will be explored further in this paper. We suggest that in the case of marine turtles, recovery planning has provided a holistic, and thus a more desirable approach, than a threat abatement plan that would have dealt only with one of a number of threatening processes.
Minimising marine turtle bycatch in trawl fisheries has been an issue for the fishing industry and its management agencies for a number of years. The management of marine turtle bycatch in the trawl fisheries of northern Australia has preceded and then run in parallel with the recovery plan and the nomination of trawling as a key threatening process to a large degree (Fig. 1).
Development of the national recovery plan for marine turtles
Marine turtles in Australia generally have a tropical and subtropical distribution, with the exception of the leatherback, which can be found in temperate waters. Under the Australian Constitution, the States and Territories have responsibility for wildlife and land management. As marine turtles are protected in State and Territory jurisdictions, the development of a national recovery plan for marine turtles in Australia requires the Commonwealth Government to work in close collaboration and cooperation with representatives of the States and the Northern Territory.
Each jurisdiction consulted with groups including non-government organisations (NGOs), fishery managers and industry bodies and indigenous groups within their boundaries, on issues raised during the preparation of the recovery plan. The role of the recovery team is articulated in Male (1996) but to date it has largely assisted in shaping the content of the plan. Recovery team members may have a major role in implementing many of the actions identified in the plan. Some fisheries management agencies chose to be represented on the recovery plan team because fisheries interactions with marine turtles was a prominent issue to be dealt with by the recovery plan, and because many fisheries already had some plans, procedures or policies in place to address marine turtle bycatch.
The recovery plan deals with all marine turtles as a group, since all species are listed as endangered or vulnerable under the ESPA, and because many of the threats and issues relate to more than one species. The following key issues have influenced the development of the recovery plan.
i) The drastic decline of loggerhead turtles (Limpus and Reimer 1994).
ii) The quantification of marine turtle catch and mortality in the Northern Prawn Fishery (Poiner and Harris 1996) and the Queensland East Coast Trawl Fishery (Robins 1995) (Table II).
iii) The nomination of otter trawling as a key threatening process under Schedule 3 of the ESPA.
iv) The development of fisheries management plans (i.e. Northern Prawn Fishery bycatch action plan and the Queensland East Coast Trawl Fishery draft management plan) that included the mitigation and management of the impacts of otter-trawling on marine turtles.
v) The progress of the trawling industry of northern Australia in testing and developing turtle excluder devices (TEDs), and an ongoing multi-agency program to work in close collaboration with the trawling industry to develop and adopt TEDs and bycatch reduction devices (BRDs) (Robins1997).
vi) The 1996 USA embargo on the importation of wild-shrimp caught without the use of TEDs and the subsequent World Trade Organisation challenge and decision.
One advantage of the recovery plan was that it collated all available information on the level of detail on marine turtle mortality and its causes, and whether this information was available for all species. It became apparent that there were many gaps in the current knowledge of the magnitude of marine turtle mortality from the identified threats and the status of the effected populations. This made it difficult to be prescriptive about what actions needed to be taken in relation to poorly defined or understood threats. This led the recovery team to adopt a threat-based approach.
Although the recovery team received some criticism for this approach, it is an appropriate expression of the precautionary principle, defined in the Intergovernmental Agreement on the Environment (DASET 1992) as
"Where there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. In the application of the precautionary principle, public and private decisions should be guided by careful evaluation to avoid wherever practicable, serious or irreversible damage to the environment; and an assessment of the risk-weighted consequences of various options"
The following threats were identified as having, or were suspected as having, an unacceptable impact on turtle populations:
i) marine debris,
ii) customary (indigenous) harvest,
iii) trawl fisheries interactions,
iv) non-trawl fisheries and boating interactions,
v) shark control activities,
vi) predation by feral animals on eggs,
vii) loss of habitat.
The mitigation of these impacts will in all probability take decades on a national scale. The effort will need to be substantial and cooperation across jurisdictions will be a critical factor, as will the coordination through the implementation of the recovery plan.
The plan also identified the need to obtain meaningful information on marine turtle stocks. Tools that lend power and robustness to the interpretation of the status of marine turtle stocks include the complete identification of genetic stocks, monitoring of key stocks or populations, and modelling of stocks to provide decision-making tools for managers.
Otter trawling as a key threatening process: past and present
Otter trawling was nominated as a key threatening process in 1995. The Commonwealth Government, through the Endangered Species Scientific Subcommittee (ESSS) sought comments on the nomination. Fisheries management agencies provided comments that did not support the nomination and did not believe that the development of a threat abatement plan was a feasible means of addressing the incidental bycatch of turtles in prawn fisheries. Government conservation agencies provided information on the relative importance of trawl by- catch to the decline of the East Coast loggerhead turtle populations, while non- government conservation groups lobbied strongly in favour of the nomination.
Interim advice from the ESSS was issued in late 1997. It stated essentially that further consideration of whether to list trawling as a key threatening process to marine turtle populations may not be necessary if the fishing industry and fishery management agencies could implement effective programs for reducing turtle capture, using Turtle Excluding Devices (TEDs) to mitigate turtle bycatch.
The Commonwealth Minister for the Environment considered the nomination and the final advice provided by ESSS (ESSS 1999). The advice recommended that otter trawling be listed as a key threatening process but the Minister, in deciding not to list, accepted advice from the Attorney General that the Constitutional and legislative arrangements prevent a threat that occurs in State and Commonwealth waters from being listed. This loophole will be removed with the coming into force of the Environment Protection and Biodiversity Act 1999 in July 2000.
The complexities in considering the advice is that the Commonwealth may not make decisions that effect State or Territory land or waters, unless made under the external powers provision of the Constitution. Under the Australian Constitution the management of land and wildlife is the responsibility of the States (Zines 1985). These constitutional arrangements provide opportunities for coordination and advice. A national recovery plan can coordinate actions in the Commonwealth, States and the Northern Territory and can address the issues raised in the nomination of otter trawling as a key threatening process.
Marine turtle bycatch: the approach by two major trawl fisheries
The Northern Prawn Fishery occurs in waters from Cape York in Queensland to Cape Londonderry in Western Australia (Fig. 2). The Queensland East Coast Trawl Fishery occurs between about 10°S and 28°S along the East Coast of Queensland (Fig. 2). Catch and effort is not uniformly distributed along the coast with four areas showing a concentration of effort. More than 70 % of the total catch and effort of the Queensland East Coast Trawl Fishery occurs within the Great Barrier World Heritage Area (Tanzer et al. 1997). The Northern Prawn Fishery and the Queensland East Coast Trawl Fishery are limited entry fisheries, and are subject to a range of management measures by the Australian Fisheries Management Authority and the Queensland Fisheries Management Authority respectively.
Fisheries research and management agencies anticipated major pressures within Australia for the turtle bycatch problem to be mitigated (see Fig.1) and began monitoring and data collection programmes to assess catches of turtles in prawn trawl fisheries using trained volunteer commercial fishers. This research documented the catch and mortality of sea turtles in trawl nets (Table II).
Table II: Numbers of turtles estimated to have been caught and drowned in the tiger prawn sector of the Northern Prawn Fishery (NPF) (Poiner and Harris 1996) and Queensland East Coast Otter Thawl Fishery (ECOTF); (CPUE: catch per unit effort i.e. turtles caught per standard net hour of trawling) (from Robins 1995).
The strength of concern over the potential impact of turtle bycatch caused a number of Australian research agencies to investigate the effectiveness and consequences of various TEDs (Robins-Troeger 1994, Robins-Troeger et al. 1995, Blaber et al. 1997, Brewer et al. 1998). Research studies on TEDs provided initial first-hand experience of the performance of TEDs in Australian fishing grounds and were effective in raising the awareness of the local trawl industry about the feasibility and need for TEDs in Australian prawn trawl fisheries. It also played a dual role in raising the awareness of commercial fishers to the seriousness of this issue and gave the fishing industry some responsibility for marine turtle bycatch. The availability of TED technology developed in the USA (Watson et al. 1994) reduced the developmental effort to find devices that could be modified to suit northern Australian trawling conditions.
The development and adoption of a Code of Fishing Conduct and Recovery Procedures for Turtle Captures (Anon. 1995) in the Queensland East Coast Trawl Fishery in 1995 and the Northern Prawn Fishery in 1996 signalled that the fishing industry had accepted some responsibility for the turtle bycatch issue and were looking to play a proactive role in developing acceptable and workable solutions to the problem. Assisting marine turtles that were effected by capture in a trawl net was less threatening to many fishers than the concept of using TEDs and assisted in improving fishermen's awareness of the impacts of trawl captures on marine turtles. Turtle Excluder Devices were seen by many agencies as the panacea to the problem of marine turtle bycatch. The Queensland fishing industry was not so convinced of the scale of the turtle bycatch problem nor of the practicalities of TEDs, and have lobbied that TEDs should be mandatory in areas where marine turtles are frequently caught or killed, rather than a have a blanket coverage approach, such as occurred in the USA (Tucker et al. 1997).
A cooperative approach to dealing with marine turtle bycatch was adopted because:
i) there was limited ability to enforce TED regulations in practice as many trawling grounds were remote and the activities of enforcement personnel were quickly "telegraphed" throughout the fleet;
ii) it was hoped that solutions to the marine turtle bycatch problem that were agreed to and supported by the fishing industry had better chance of acceptance and compliance by fishers; and
iii) experienced industry members were best placed to assist in the development of appropriate technology.
In an effort to improve the fishing industry's awareness of TEDs and to encourage their development and use in northern Australia, a large-scale, multi- agency extension project on TEDs and bycatch reduction devices (BRDs) was supported in northern Australia. The project aimed to provide northern Australian trawl fishers with first-hand information, exposure and, if desired, experience with turtle excluder devices at minimal or no cost to the individual. Financial support for the program was largely contributed by the Commonwealth Fisheries Research and Development Corporation, under its "Effects of Fishing" sub-program. One of the roles of this sub-program was to foster cooperative and collaborative ventures between researchers, fisheries managers and the fishing industry. The extension work was strongly supported by the Queensland Commercial Fishermen's Organisation, the Northern Prawn Fishing Industry Organisation, and the respective management agencies. The extension project was seen to be a vital link in the process of industry acceptance of TEDs. Voluntary use of TEDs varied within the Queensland East Coast Trawl Fishery. TEDs were predominantly used by fishers who could see a benefit to their use (e.g. turtle or jellyfish exclusion) or by individuals who used TEDs in trials and found no adverse effects in terms of catch reduction or safety issues.
Legislatively-based regulations requiring the use of TEDs by trawlers have been developed for both fisheries. The Northern Prawn Fishery Management Advisory Committee (NORMAC) finalised the first Australian bycatch action plan for the fishery in 1998 and agreed to the compulsory use of TEDs, on all vessels in all areas, throughout the fishery from the 2000 fishing season (NORMAC 1998). At the same time NORMAC agreed to the use of bycatch reduction devices to exclude fish and other unwanted bycatch. The fishery's managers and advisory committee issued a notice strongly encouraging industry to trial TEDs in order that operators would be best able to use the gear once it became compulsory.
The Queensland Fisheries Management Authority, through the State Govemment, legislated for the compulsory use of TEDs from 1st May 1999 in seven priority areas where there was an appreciable risk of marine turtles, in particularly Loggerhead turtles, being caught or drowned in trawl nets. Legislatively based requirements for the use of TEDs are an integral part of the Queensland East Coast Trawl Fishery draft management plan, preparation of which was initiated in 1996 (Anon. 1996, Anon. 1999). This management plan addresses a range of issues and objectives facing the industry, including the objective of ensuring that trawling is carried out in such a way that any impacts on threatened or endangered species (such as marine turtles) were negligible and accepted as such by key conservation agencies. The strategy adopted in the Queensland East Coast Trawl Fishery draft management plan was to require the use of accepted and effective TEDs in areas where the incidence of turtle capture was considered high. This approach was adopted to avoid clashes between the fishing industry, conservation groups and government agencies, as occurred during the blanket regulation of TEDs in the south eastern USA (Margavio et al 1993, Moberg & Dwyer 1994, Tucket et al 1997), and to give industry a degree of control and ownership and responsibility about introduction of TEDs. These seven priority areas for TED use were initially identified by fisheries research staff and later supported as priority areas by a multi-agency risk assessment (Slater et al 1998). The seven areas also have the full support of the Queensland fishing industry. Negotiation is currently underway between the Queensland government and the Commonwealth government as to whether the areas in which TEDs are required should be expanded and appropriate introduction dates for such regulations. Drafting of the national recovery plan for marine turtles was well under way when mandatory use of TED was regulated through fisheries legislation (Fig. 1).
Recovery plans versus threat abatement plans
It may be argued that, as the recovery plan adopts a threat based approach, it is a de facto threat abatement plan. When the outputs of the two processes are examined we find that where the recovery plan is prescriptive across a range of threats and issues, the threat abatement plan has the capacity to deliberate about the listed key threat. In the case of marine turtles, the long term benefit of pursuing a number of objectives must be weighed against the more narrow focus of the threat abatement plan. The recovery planning process allows for the development of alternative approaches and this flexibility can ultimately abate threats and argues for resources that delivers recovery.
The national recovery plan and any potential threat abatement plan would both address issues of marine turtle bycatch in otter trawling operations. We suggest that in this case, managing the threats to marine turtles in Australia through a national recovery plan has significant advantages:
i) Recovery plans can be inclusive of the broad range of issues that affect marine turtles, including otter trawling.
ii) The recovery plan has identified clear objectives, and the actions needed to achieve these objectives.
iii) The cost and timing of the plan can be estimated.
iv) Gaps in our current knowledge can be identified and highlighted as priority areas for research or mitigation.
v) The recovery plan is based upon the precautionary principle.
vi) The tools for dealing with threats or the need to develop them can be identified.
vii) The recovery plan allows strategic priorities to be set, enabling resources to be allocated in an efficient manner.
Recovery planning addresses marine turtle issues on a national scale, which is vital for a group of species that are distributed across several jurisdictions and are subject to a range of threats.
The mitigation and management of threats to marine turtles in Australia has had several activities occurring in parallel. These include the national recovery plan and plans by various fishing management agencies to address sea turtle bycatch in trawl fisheries of northern Australia. The national recovery plan has taken advantage of this opportunity upon which to build a coordinated and planned approach to dealing with the complex array of threats to marine turtles, across several jurisdictions and with a diverse range of interest groups. The recovery plan identifies prescriptive actions where information is available (Table III). It has identified gaps in the current knowledge, and the means to collect and collate meaningful data for species that migrate across state, national and international boundaries. The national recovery plan also argues for the tools that assist in the interpretation of the data e.g. genetic clarification of marine turtle stocks.
Table III: Prescribed actions in the national recovery plan that address marine turtle bycatch in trawl fisheries.
* The arrangements for TED use are still subject to ongoing negotiations. It is agreed that some level of usage is required to mitigate otter trawl impacts on marine turtles.
Fisheries agencies are addressing the incidental catch of marine turtles in otter trawls by encouraging the development of appropriate technology for the particular fishing grounds, involving industry in the monitoring of turtle captures with education and training in turtle identification, developing handling techniques to maximise turtle survival and in the testing of TEDs. To date this approach has avoided the need for legal challenges. The long-term collaborative approach has demonstrated several benefits including the industry ownership of the turtle bycatch issue, their contribution to its solution and the understanding of industry perspective by government research and management agencies. These factors have contributed to stakeholder understanding and have restrained the desire to litigate in order to progress the solution.
However, the long-term collaborative approach has some costs. These indude a delay of some 10 years between when the main problem was identified (in 1990) to the solution being implemented (1999/2000 and onwards). Also, the problem of conserving marine turtles is seen by several stakeholders to be only partially resolved. The mandatory use of TEDs will significantly mitigate the catch of marine turtles in trawl nets. Except for the ongoing negotiations in Queensland about the final form of the scope of implementation, it has been achieved with minimal conflict and substantial efficiency. It provides the platform for continued negotiation between various stakeholders (e.g. State and Commonwealth agencies, commercial fishing interests and conservation agencies) on how the remaining impacts on marine turtles can be addressed. The production of the recovery plan addresses the issues raised by the key threatening process nomination and provides the capacity for a coordinated approach.
This manuscript was developed from the presentation given at the 2nd ASEAN Symposium on Sea Turtle Biology and Conservation. Environment Australia and the Fisheries Research and Development Corporation supported our attendance at the symposium. We thank A. McNee and M. Dredge for comments on the manuscript.
Australian Bureau of Agricultural Resource Economics (ABARE), 1998. Australian Fisheries Statistics - 1998. Australian Government Printer, Canberra: 51pp.
Anon., 1995. Turtle recovery procedures and Code of Fishing Ethics: the capture of sea turtles. Queensland Commercial Fisherman's Organisation and the Queensland Department of Primary Industries, Brisbane: 4p.
Anon., 1996. Discussion Paper No. 5: Queensland Trawl Fishery. Queensland Fisheries Management Authority, Brisbane: l00p.
Anon., 1999. Queensland East Coast Trawl Fishery draft management plan and regulatory impact statement. Queensland Fisheries Management Authority, Brisbane: 220pp.
Blaber, S., D. Brewer, C. Burridge, M. Farmer, D. Milton, J. Salini, Y. Wang, T. Wassenberg, C. Buxton, I. Cartwright, S. Eayrs, N. Rawlinson, R. Buckworth, N. Gill, J. MacCartie, R. Mounsey & D. Ramm, 1997. Effects of trawl design on bycatch and benthos in prawn and finfish fisheries. Final Report for FRDC Project No 93/179. CSIRO Division of Marine Research, Cleveland, Australia: 190pp.
Brewer, D., N. Rawlinson, S. Eayrs & C. Burridge, 1998. An assessment of Bycatch Reduction Devices in a tropical Australian prawn fishery. Fisheries Research. 720: 1- 21.
DASET, 1992. The Intergovernmental Agreement on the Environment. The Department of the Arts, Sport, the Environment and Territories, Canberra: 40pp.
ESSS, (1999). Advice to the Minister for the Environment and Heritage from the Endangered Species Scientific Subcommittee (ESSS) on a public nomination to Schedule 3 of the Endangered Species Protection Act 1992 (ESP Act). Unpublished, August 1999.
Limpus, C. & D. Reimer, 1994. The loggerhead turtle, Caretta caretta, in Queensland: a population in decline. In: Proceedings of the Australian Marine Turtle Conservation Workshop, compiled by R. James. Queensland Department of Environment and Heritage and the Australian Nature Conservation Agency, Canberra: 39-59.
Male, B., 1996. Recovery of Australian threatened species - a national perspective. In: Back From the Brink: Refining the Threatened Species Recovery Process (S. Stephens and S. Maxwell, eds). Beatty and Sons, Surrey: 23-27.
Margavio, A.V., S. Laska, J. Mason & C. Forsyth, 1993. Captives of Conflict: the TEDs case. Society and Natural Resources, 6: 273-290.
Moberg, M. & C.L. Dyer, 1994. Conservation and forced innovation: Responses to turtle excluder devices among Gulf of Mexico shrimpers. Human Organization, 53: 160-166.
Northern Prawn Fishery Advisory Committee (NORMAC), 1998. Northern Prawn Fishery bycatch action plan. Australian Fisheries Management Authority, Canberra: 21pp.
Robins, J.B. 1995. Estimated catch and mortality of sea turtles from the east coast otter trawl fishery of Queensland, Australia. Biological Conservation, 74:157-167.
Robins, J.B. 1997. The adoption of bycatch reduction gear technology: a Cook's tour. In: Asia-Rae//ic Fishing 97, Baird Publications, Melbourne: 91-95.
Robins-Troeger, J.B., 1994. Evaluation of the Morrison soft TED: prawn and bycatch variation in Moreton Bay, Queensland. Fisheries Research, 19: 205-217.
Robins-Troeger, J.B., R.C. Buckworth & M.C.L. Dredge, 1995. Development of a trawl efficiency device (TED) for Australian prawn fisheries II: Field evaluations of the AusThD. Fisheries Research, 22:107-117.
Slater, J., C. Limpus, J. Robins, F. Pantus & M. Chaloupka, 1998. Risk assessment of sea turtle capture in the Queensland East Coast Otter Trawl Fishery. Report prepared for the Trawl Management Advisory Committee, Queensland Fisheries Management Authority. Queensland Department of Environment, Brisbane: 131pp.
Tanzer, J., M. Elmer & T. Healy, 1997. Fisheries management in the Great Barrier Reef region. In: The Great Barrier Reef: science, use and management a national conference (N. Tuna and C. Daliston, eds). Great Barrier Reef Marine Park Authority, Townsville: 298-308.
Tucker, A.D., J.B. Robins & D.P. McPhee, 1997. Adopting TEDs in Australia and the USA: what differences are there in technology transfer, promotion and acceptance. Coastal Management, 25: 405-421.
Watson, J., I. Workman, D. Foster, C. Taylor, A. Shah, J. Barbour, J. & D. Hataway, 1994. Status report on the potential of gear modifications to reduce finfish bycatch in shrimp trawls in the southeastern United States 1990-1992. NOAA Technical Report NMFS-SEFSC-327, Pascagoula, USA: 131pp
Zines, L., 1985. The environment and the Constitution. In: Federalism and the Environment (R.L. Mathews ed). Centre for Research on Federal Financial Relations, The Australian National University, Canberra: 13-28.