LINEFISH RESILIENCE IN THE ANTHROPOCENE: th The Proceedings of the 5 Southern African Marine Linefish Symposium Taryn Murray, Murray Duncan, Alex Winkler, Amber-Robyn Childs, Bruce Mann, Warren Potts (Editors) ©Steve Benjamin, AnthonyJudy Bernard, Mann & Brett Pringle Acknowledgements This work would not have been possible without the contributions of scientists. The South African Institute for Aquatic Biodiversity is thanked for their sponsorship of five student bursaries, and the National Research Foundation’s Knowledge, Interchange and Collaboration grant (no. KIC 180829354741) is acknowledged for providing funding for the keynote speaker, Dr Stephen Brouwer, to attend the symposium. Key funders Rhodes University South African Institute for Aquatic Biodiversity Citation Murray TS, Duncan MI, Winkler AC, Childs A-R, Mann BQ, Potts WM (eds). 2020. Linefish resilience in the Anthropocene: The Proceedings of the 5th Southern African Marine Linefish Symposium. Rhodes University, Makhanda, 113pp. Linefish Resilience in the Anthropocene The Proceedings of the 5th Southern African Marine Linefish Symposium Held at Mpekweni Beach Resort, Eastern Cape 8th to 11th July 2019 Edited by Taryn Murray (South African Institute for Aquatic Biodiversity) Murray Duncan (Department of Ichthyology and Fisheries Science, Rhodes University) Alex Winkler (Department of Ichthyology and Fisheries Science, Rhodes University) Amber-Robyn Childs (Department of Ichthyology and Fisheries Science, Rhodes University) Bruce Mann (Oceanographic Research Institute, South African Association for Marine Biological Research) Warren Potts (Department of Ichthyology and Fisheries Science, Rhodes University) 3 | Page Executive Summary The Fifth Southern African Marine Linefish Symposium (5th SAMLS) held at Mpekweni Beach Resort along the Eastern Cape’s sunshine coast, from the 9th – 11th July 2019 was attended by 99 delegates from a variety of academic, non-government organisation and government institutions, representing a 28% increase in delegate numbers from the last symposium held at Langebaan in 2012. This was largely attributed to the in-kind student funding provided by the NRF-SAIAB, financially supporting the attendance of five presenting students as well as 25 non-presenting undergraduate zoology students from the University of Fort Hare and Walter Sisulu University. There were 43 scientific presentations, five poster presentations, three plenaries and one keynote address by Dr Stephen Brouwer from New Caledonia, South Pacific. Dr Brouwer is an internationally acclaimed fisheries scientist who started his career working on linefish in South Africa during the height of the linefish “state of emergency”, which was declared in the year 2000. Dr Brouwer’s experience working in fisheries management in the developed and developing world has provided him a great deal with insight on options for the management of Southern Africa’s linefish populations. With the linefish “state of emergency” still in effect some 20 years later, Brouwer highlighted some of the positive steps as well as the failings and tribulations associated with linefish research and management in South Africa over the past 20 years and made several recommendations for the way forward. Unfortunately, new challenges face our iconic, endemic and charismatic linefish species in Southern Africa brought upon by the Anthropocene, an epoch categorised by fossil fuel driven climate change, habitat loss, and relentless exploitation of our natural resources. All these factors influenced the session themes held at the 5th SAMLS, being broadly based around climate change, monitoring, fish biology and the response of society to these changes. Fortunately, technological advances have aided in many aspects of linefish research, with a strong representation of studies using electronic tagging, remotely operated camera systems, metabolism-measuring equipment and even the use of web-based applications to efficiently communicate scientific findings to the public. While the ecological knowledge of linefish has always been a strength in southern Africa, it is becoming increasingly apparent that the social systems of the linefishery are under researched. During this symposium, we attempted to promote the social components of linefish management, with dedicated sessions on science communication and socioecological systems. Despite this, our knowledge on the human dimension of our linefisheries is still underdeveloped. Besides the development of this extended abstract document, the findings of this symposium have been disseminated in the form of two non-scientific public reports, which were compiled for the World Wildlife Fund and Fishing Industry News. Furthermore, selected studies have been submitted to the African Journal of Marine Science for a special issue that focusses on linefish research. Special thanks must go to the all attendees, and particularly the keynote speakers and presenting authors who graciously gave up their time to attend the conference and to the all of the sponsors for their financial support, without which, this symposium would not have been possible. 4 | Page Foreword by Dr Judy Mann Conservation Strategist and ex CEO South Africa Association for Marine Biological Research (SAAMBR) The Marine Linefish Research Group (MLRG), formerly recognised as a “Co-ordinating Group” under the South African National Committee for Oceanographic Research (the original name of SANCOR), has been a remarkable group of dedicated linefish researchers that has undoubtedly stood the test of time. Established in 1978, past chairmen of the MLRG have included Alan Heydorn, John Wallace, Rudy van der Elst, Colin Buxton, Bruce Mann, Paul Cowley, Colin Attwood and the current chairman, Warren Potts. Over this 41-year lifespan the MLRG has held five successful national linefish research symposia in East London (1989), Durban (1992), Arniston (1999), Langebaan (2012) and finally the 2019 symposium. The proceedings of all five of these symposia have been published and it is therefore a great privilege for me to be asked to write this foreword. Professionally hosted by the Department of Ichthyology and Fisheries Science (DIFS), Rhodes University and the South African Institute for Aquatic Biodiversity (SAIAB), the 5th Southern African Marine Linefish Symposium (SAMLS) was held in July 2019 at the beautiful Mpekweni Beach Resort in the Eastern Cape Province. The symposium was attended by over 60 marine linefish researchers, students, managers and science communicators from around South Africa. These proceedings highlight many of the almost 50 symposium presentations and provide a comprehensive summary of the state of marine linefish research and management in South Africa today. Reading through previous proceedings, it is clear that the topics addressed in these proceedings are far more diverse than in previous years, with the inclusion of aspects such as climate change, fish physiology and acoustic telemetry, as well as a stronger emphasis on the social and economic aspects of fisheries management. Notable are the many long-term monitoring studies which continue to provide extremely valuable information on changes in populations and systems that often cannot be revealed using short-term studies. The greater emphasis of research on fishermen reflects the growing understanding that fisheries management is as much about people and their behaviour, as it is about fish and their biology. It is encouraging to see that in addition to a greater diversity in topics, the diversity of the linefish community is also increasing, with attendance by staff and students from Rhodes University, Walter Sisulu University and the University of Fort Hare. The deliberate inclusion of more students will help to build the capacity of the next generation of linefish researchers and managers. From these proceedings, it is evident that the scientists and managers involved in research and management of South Africa’s linefish today, still exhibit the same passion for fish, fishing and fisheries management that has been evident since the 1970s. Since the early days, managers and scientists have worked together with fishermen to ensure that science was undertaken based on collaborative prioritisation, that management decisions were based on sound science and that management regulations were implemented. The foresight of the researchers who undertook the science and the managers who implemented the regulations is to be commended. Unfortunately, the current changes at multiple levels of government have the potential to decouple science from management. Furthermore, the loss of important management structures such as the South African Marine Linefish Management Association (SAMLMA) is cause for concern, particularly regarding management of recreational fisheries. These proceedings are a testament to the work of the members of the MLRG for over 40 years. I hope that when you read them you will feel the same sense of pride that I feel in our colleagues and friends and in South Africa’s marine linefish research and management community. Well done to Warren Potts and his team who put together an excellent symposium. 5 | Page Table of Contents Proceedings of the 5th Southern African Marine Linefish Symposium Executive summary 4 Foreword by Dr Judy Mann 5 Background to the theme: Linefish Resilience in the Anthropocene by Warren Potts 10 SESSION 1 | Fisheries 11 11 An introduction to the rich methodology to assess data-poor South African linefishes 12 SE Kerwath,