RESEARCH PUBLICATION NO. 105 Role, importance and vulnerability of top predators on the Great Barrier Reef – A review Daniela Ceccarelli and Tony Ayling RESEARCH PUBLICATION NO. 105 Role, importance and vulnerability of top predators on the Great Barrier Reef – A review Daniela Ceccarelli and Tony Ayling C&R Consulting PO Box 1379 Townsville QLD 4810 Telephone: (07) 4750 0700 Fax: (07) 4772 6093 Email: [email protected] www.gbrmpa.gov.au © Commonwealth of Australia 2010 Published by the Great Barrier Reef Marine Park Authority ISBN 978 1 921682 26 1 (pdf) This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without the prior written permission of the Great Barrier Reef Marine Park Authority. The National Library of Australia Cataloguing-in-Publication entry : Ceccarelli, D. Role, importance and vulnerability of top predators on the Great Barrier Reef - a review [electronic resource] : final report / Daniela Ceccarelli and Tony Ayling. ISBN 978 1 921682 26 1 (pdf) Research publication (Great Barrier Reef Marine Park Authority: Online) ; no. 105. Includes bibliographical references. Predatory animals--Queensland--Great Barrier Reef. Fisheries management--Queensland. Ayling, Tony, 1947- C&R Consulting. 591.53 DISCLAIMER The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government. While reasonable effort has been made to ensure that the contents of this publication are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication. Requests and inquiries concerning reproduction and rights should be addressed to: Director, Communication and Knowledge Management Group 2-68 Flinders Street PO Box 1379 TOWNSVILLE QLD 4810 Australia Phone: (07) 4750 0700 Fax: (07) 4772 6093 [email protected] Comments and inquiries on this document are welcome and should be addressed to: Chief Scientist, Director Science Coordination [email protected] www.gbrmpa.gov.au RESPONSE TO THE REPORT This report contributes to our knowledge and understanding of the role and importance of apex predators within the Great Barrier Reef Ecosystem. It reinforces that the role of predation in tropical marine ecosystems is complex and spread across a range of species and habitats that are connected in ways that are not well understood. It reinforces the need to verify the status of shark and other important predator populations within the Great Barrier Reef ecosystem. The Great Barrier Reef Marine Park Authority (GBRMPA) has carefully considered the Report's recommendations and will factor them, as appropriate, into its strategic planning and the ongoing development of research and management priorities in the light of the direction provided by the Outlook Report. Recommendation GBRMPA Comment Improved integration is required between When deciding on whether to approve the fisheries and ecosystem management and Wildlife Trade Operation (WTO) for the better application of ecosystem-based ECIFF, the Minister set a number of fisheries management (Pikitch et al. 2004). conditions that were aimed at improving For instance, a panel charged with the ecosystem-based fisheries reviewing the proposed new management management of the ECIFF. Many of these arrangements for the ECIFF [East Coast conditions relate to improved protection for Inshore Finfish Fishery] considered that high level predators, including sharks. this fishery is operating within a MPA [marine protected area] in a World Heritage Area, and the arrangements to protect the sustainability of sharks were not sufficient. However, the new management arrangements included scope for a shark TAC [total allowable catch] of 600t, and for interactions with protected species (Gunn et al. 2008). It is recommended that the GBRMPA Other more extensive research has assess the viability of establishing a identified that regional variation in the greater number and area of Pink (no-go) apparent effectiveness of Marine Protected Zones on the GBR; recent work on a Areas is likely to reflect long-standing number of generalist top predators regional variations in the amount of fishing suggests a much better level of and its impacts outside closed areas, compliance in Pink Zones than Green (no- rather than wholesale subversion of zoning take) Zones. It is recommended that the strategies by high levels of poaching (see GBRMPA investigate the viability, cost and quote from Mapstone et al., below). Given logistics of enabling further legislative this, the GBRMPA considers that focussed protection of predators, prioritising species education and compliance programs, for consideration according to this review's combined with advances in surveillance risk assessment. technology, will provide a more cost- effective and appropriate solution than increasing the area of Pink (no-access) Zones. Improved education is required on the The GBRMP Act (1975) has been recently importance of green zone compliance. reviewed and a number of amendments Better enforcement and stricter penalties were made to increase penalties and for infringing on green zones; current strengthen the basis for enforcement. levels are not adequately deterring non- Research and monitoring, including counts i compliant fishers (Ayling & Choat 2008). of sharks and reef fishes, provides valuable intelligence of hot-spots of non- compliance. This information is being used to target surveillance and education efforts. The GBRMPA is also developing a communication strategy to better promote the overall effectiveness of marine park zoning; not just focussing on no-take zones. "Surveys of areas that had been open and closed to fishing for over a decade showed that the two main target species of the RLF, the common coral trout and the red throat emperor, were significantly more abundant, larger and older in areas zoned Marine National Park ‘B’ (and so closed to fishing) than in adjacent General Use areas that have always been open to fishing. The magnitude of these differences varied regionally, from near-zero around Lizard Island to several-fold for some population characteristics in the southern regions of the GBR. The pattern in apparent ‘effectiveness’ of past closures matched closely patterns in the amount of fishing effort and catch and underlying patterns in the abundances of several harvest and non-harvest species. We present circumstantial arguments that this regional variation in the apparent ‘effectiveness’ of Marine Protected Areas is likely to reflect long- standing regional variations in the amounts of fishing and its impacts outside closed areas, rather than wholesale subversion of zoning strategies by high levels of poaching. That is, the lack of contrast between open and closed areas in the Lizard Region probably arises because the open areas are lightly fished, whereas the strong contrasts in the other regions arises because of relatively heavy fishing in the open areas in those regions." Quote from Mapstone et al. (2004) The effects of line fishing on the Great Barrier Reef and evaluations of alternative potential management strategies. Technical Report No. 52, CRC Reef research Centre, Townsville. Research recommendation Proposed response (quoted verbatim) Effective censuses of the status and catch of The recommended research would those species prioritised through the risk potentially advance the knowledge assessment (especially those falling into the base pertaining to the conservation ‘extreme’ and ‘very high’ risk categories are an status of apex predators in the essential first step towards understanding the Marine Park. However, the need for current status of the most important predators on the research must be considered in the GBR. This would help to determine which the context of existing research species are undergoing the greatest decline, and priorities, which are outlined in the assist in further prioritising limited resources for document titled "Scientific more detailed biological and ecological studies. information needs for the management of the Great Barrier Reef Marine Park 2009 – 2014". Distribution, abundance and life-history data is The recommended research would required for many of the predator species. Some potentially advance the knowledge of this research is underway for some species, base pertaining to the threats and but it needs to be completed for all exploited GBR risks to apex predators in the Marine sharks as a priority. It is suggested that research Park. However, the need for the on individual species be prioritised according to research must be considered in the this review’s importance index and / or risk context of existing research ii assessment. Research on individual species, priorities, which are outlined in the particularly sharks, should include: document titled "Scientific - Life history and habitat use information information needs for the for all species, especially those caught management of the Great Barrier by fisheries and prioritising the most ‘at Reef Marine Park 2009 – 2014". risk’; - Logbooks and observer programs that distinguish between species as much as possible. Better effort and catch data for all species across all fisheries, with better and more regular reporting mechanisms; - Records of how many sharks a year are taken as by-catch;