Incidental catch (bycatch) of sea turtles during coastal otter-trawling operations in Australian waters north of 28°S

Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee on a public nomination of a Key Threatening Process under the Environment Protection and Biodiversity Conservation Act 1999

1. Name and description of the key threatening process

Name

'Incidental catch (bycatch) of sea turtles during coastal otter-trawling operations in Australian waters north of 28°S'

This nomination was originally submitted under the Endangered Species Protection Act 1992 (ESP Act).

Description

The description of the threatening process is based on that provided in the nomination:

'Incidental catch (bycatch) of sea turtles during coastal otter-trawling operations in Australian waters north of 28°S' is the catch of marine turtles during trawls for penaeid prawns and scallops that use the outward force of otter boards to spread the mouth of a net. The net is configured to trawl the fishing grounds with the footrope or a 'tickler' chain in contact with the substrate and a headline with fixed floats to open the net vertically. Marine turtles are taken by this trawling method and can be injured during the trawl and/or become trapped in the codend of the net where they will drown during trawls.

2. How judged by EA in relation to the Environment Protection and Biodiversity Conservation Act 1999 criteria

Section 188(4) of the Environment Protection and Biodiversity Conservation Act 1999 states:

A threatening process is eligible to be treated as a key threatening process if:

  1. it could cause a native species or an ecological community to become eligible for listing in any category, other than conservation dependent; or b) it could cause a listed threatened species or a listed threatened ecological community to become eligible to be listed in another category representing a higher degree of endangerment; or c) it adversely affects 2 or more listed threatened species (other than conservation dependent species) or 2 or more listed threatened ecological communities.

In assessment of the original nomination ESSS found:

A. the process meets the ESP Act criterion for 'adversely affecting two or more listed species'; B. the process meets the ESP Act criterion 'that it could cause native species that are not Endangered to become Endangered'; C. the Olive Ridley Turtle Lepidochelys olivacea, is eligible for listing as Endangered; and D. the Flatback Turtle, Natator depressus, is eligible for listing as Vulnerable.

The nomination resulted in listing of the Olive Ridley and Flatback Turtles. The threatening process could not legally be added to the list of key threatening processes under the ESP Act, since it occurs both in and outside Commonwealth areas. This restriction is no longer applicable under the EPBC Act.

A. Could the threatening process cause a native species or an ecological community to become eligible for listing as Extinct, Extinct in the Wild, Critically Endangered, Endangered or Vulnerable?

The implementation of appropriate Turtle Excluder (or Exclusion) Device (TED) technology has been identified as a means of reducing: the bycatch and mortality of marine turtles; the take of other large or aggregating marine wildlife; and the retention of large amounts of benthos in otter trawl fisheries. The development of TED technology in Australia has resulted in the development of a range of TED models that can be used in a variety of otter trawl circumstances. The Draft Marine Turtle Recovery Plan has identified the use of TED technology in trawl fisheries throughout Australia as a priority in reducing threats to marine turtles.

Each of the jurisdictions that manage otter trawl fisheries (north of 28°S) has introduced or has a timetable for the introduction of TEDs or Bycatch Reduction Devices (BRDs).

Conclusion: Given that the relevant jurisdictions are committed to the implementation or assessment of the need for marine turtle bycatch mitigation, TSSC considers that the threatening process is not likely to cause a native species or an ecological community to become eligible for listing as Extinct, Extinct in the Wild, Critically Endangered, Endangered or Vulnerable, and therefore is not eligible under this criterion.

B. Could the threatening process cause a native species or an ecological community to become eligible to be listed in another category representing a higher degree of endangerment?

Research has demonstrated that otter trawling, in the absence of marine turtle bycatch mitigation, would continue to adversely affect species of marine turtles. Earlier advice (by ESSS) found that otter trawling could cause Loggerhead, Olive Ridley and Flatback Turtles to become Endangered. In response to the ESSS advice the Olive Ridley Turtle was listed as Endangered and Flatback Turtle as Vulnerable.

To determine whether otter trawling continues to pose the same level of threat to marine turtles requires assessment of: the fisheries where TEDs are compulsory, and the consequences of any delays from time-tabling the implementation in other fisheries. Each of the jurisdictions that manage otter trawl fisheries (north of 28°S) has introduced or has a timetable for the introduction of TEDs or Bycatch Reduction Devices (BRDs). Monitoring of the introduction and performance of TEDs and BRDs has been increased. The program in the Northern Prawn Fishery (NPF) will provide substantial guidance about the effectiveness of TEDs (and BRDs) in mitigating marine turtle bycatch.

Conclusion: Based on the past evidence and current initiatives to implement TEDs in otter trawls, TSSC considers that the threatening process is not likely to cause any more marine turtle species to become eligible to be listed in another category representing a higher degree of endangerment, and therefore is not eligible under this criterion. TSSC recommends that this be reviewed in 12 months to monitor progress on implementation and effectiveness of TED performance.

C. Does the threatening process adversely affect 2 or more listed threatened species (other than conservation dependent species) or 2 or more listed threatened ecological communities?

ESSS concluded that two species - the Loggerhead and the Olive Ridley Turtles - were adversely affected by otter trawling.

The magnitude of the threat to marine turtles from otter trawling has been previously established. Although a substantial amount of effort has gone into the development of appropriate TED technology within the fishing industry, TEDs are not yet compulsory in all otter trawl operations. Currently TEDs are compulsory for the Northern Prawn Fishery, the Queensland Fisheries Service is near to implementation and Fisheries Western Australia has made a substantial commitment to future mitigation of marine turtle bycatch.

Conclusion: Based on previous evidence provided and summarised above, TSSC considers that the threatening process may still adversely affect two or more listed marine turtles (Loggerhead, Flatback and Olive Ridley Turtles), and is therefore eligible under this criterion, but should be reassessed in 12 months to determine to what extent that threat remains.

Conclusion - TSSC consider that 'Incidental catch (bycatch) of sea turtles during coastal otter-trawling operations in Australian waters north of 28°S' adversely affects 2 or more listed threatened species (other than conservation dependant). The threatening process meets s188(4)(c) of the EPBC Act.

3. Threat Abatement Plan

The mitigation actions currently in place are described above, vis:

  • TEDs are compulsory in the Northern Prawn Fishery;
  • the Queensland Fisheries Service (in consultation with the Great Barrier Reef Marine Park Authority) have negotiated a compulsory TED use regime for the Queensland East Coast Otter Trawl but this is currently awaiting (Queensland) Cabinet approval; and
  • Fisheries Western Australia are trailing TEDs in Shark Bay and have scheduled the completion of Bycatch Action Plans for priority A fisheries by the end of 2001 and implementation in 2002-03 including the compulsory use of TEDs in all prawn fisheries.

Conclusion - The TSSC believe that a threat abatement plan is not warranted at this stage given current actions and plans by industry to implement bycatch mitigation devices.

4. Recommendations

  1. The TSSC recommends that the list referred to in section 183 of the EPBC Act be amended by including in the list as a key threatening process: 'The incidental catch (bycatch) of sea turtles during coastal otter-trawling operations in Australian waters north of 28°S'
  2. A Threat Abatement Plan is not considered to be a feasible, effective and efficient way to abate the threatening process.
  3. While noting that Turtle Exclusion Devices (TEDs) are not yet fully deployed, the Committee recommends that:
    1. the actions specified in the draft recovery plan for marine turtles are accepted as the mechanism for progressing actions to further mitigate marine turtle bycatch;
    2. the effectiveness of TED implementation programs in otter trawl fisheries is reviewed in 12 months to assess their effectiveness and if the assessment reveals that the threat continues the TSSC will prepare advice on the feasibility, effectiveness or efficiency of having and implementing a threat abatement plan; and
    3. listing of this process be reviewed when TEDs are fully deployed.