State of our Gulf Tıikapa Moana – Hauraki Gulf State of the Environment Report 2011 State of our Gulf Tıikapa Moana – Hauraki Gulf State of the Environment Report 2011 First published August 2011 Published by: Hauraki Gulf Forum c/o Auckland Council Private Bag 42300 Auckland, 1142 The Hauraki Gulf Forum is a statutory body, established under the Hauraki Gulf Marine Park Act 2000, responsible for the promotion and facilitation of integrated management and the protection and enhancement of the Hauraki Gulf. The Forum has representation on behalf of the Ministers of Conservation, Fisheries and Mäori Affairs, elected representatives from Auckland Council (including the Great Barrier and Waiheke local boards), Waikato Regional Council, and the Waikato, Hauraki, Thames-Coromandel and Matamata-Piako district councils, plus six representatives of the tängata whenua of the Hauraki Gulf and its islands. Contact: Tim Higham Hauraki Gulf Forum Manager, Auckland Council ph 09 624 4749, [email protected] www.haurakigulfforum.org.nz Photography Roger Grace, Shane Kelly 978-1-927169-88-9 (Print) 978-1-927169-89-6 (Online) Disclaimer While Forum members and their consultants have exercised all reasonable skill and care in controlling the contents of information contained in this report, they accept no liability in contract, tort or otherwise howsoever, for any loss, damage, injury or expense (whether direct, indirect or consequential) arising out of the provision of this information or its use by you or others. 4 Tikapa Moana – Hauraki Gulf Table of Contents Chairman's Foreword 7 1. Executive Summary 9 2. Background 15 2.1 The Park 16 2.2 The Hauraki Gulf Forum and the State of the Environment Report 17 3 The Gulf 21 3.1 Natural setting 22 3.1.1 Geology 22 3.1.2 Rivers 24 3.1.3 Currents and circulation 24 3.1.4 Sediments 26 3.1.5 Reefs 28 3.1.6 The gulf ecosystem 29 3.1.7 Terrestrial ecology 33 3.2 Human impacts 34 3.3 Strategic considerations 41 4 Environmental Indicators 43 4.1 Fisheries 44 4.1.1 Fishing in the Hauraki Gulf 45 4.1.2 Indicators of fisheries sustainability 47 4.1.3 Snapper 50 4.1.4 Crayfish 53 4.1.5 Cockles 55 4.1.6 Ecosystem indicators 57 4.1.7 Benthic disturbance 60 4.1.8 Strategic considerations for fishing 61 4.2 Sediment contamination 63 4.2.1 Strategic considerations for sediment contamination 64 4.3 Nutrients 66 4.3.1 River loads of nutrients 67 4.3.2 Wastewater inputs 69 4.3.3 Coastal nutrients 69 4.3.4 Strategic considerations for nutrients 72 4.4 Beach water quality 72 4.4.1 Strategic considerations for bathing beach quality 73 4.5 Sediment 75 4.5.1 Coastal sedimentation 75 4.5.2 Mangroves 75 4.5.3 Total suspended solids 78 4.5.4 Sediment characteristics and effects on seabed communities 78 4.5.5 Strategic considerations for sediment 79 4.6 Introduced (non-indigenous) marine species 81 4.6.1 Strategic considerations for introduced marine species 82 4.7 Harmful algae, pathogens and mass mortalities 84 4.7.1 Strategic considerations for harmful algae, pathogens and mass mortalities 85 4.8 Litter 86 4.8.1 Trends and characteristics of litter 86 4.8.2 Strategic considerations for litter 87 State of the Environment Report 2011 5 4.9 Maintenance and recovery of biodiversity 88 4.9.1 Islands of the Gulf 88 4.9.2 Shorebirds 94 4.9.3 Seabirds 96 4.9.4 Bryde’s whales 101 4.9.5 Strategic considerations for the maintenance and recovery of biodiversity 101 4.10 Coastal development 102 4.10.1 Development around bays and beaches 102 4.10.2 Trends and patterns in new development 104 4.10.3 Loss of camping grounds 107 4.10.4 Overlap between development and outstanding natural landscapes 107 4.10.5 Strategic considerations for coastal development 108 5 R esearch Gaps and Opportunities (invited contribution by Dr Simon Thrush and Professor John Montgomery) 111 5.1 Do we know what the issues are? 112 5.2 Ecosystem-based management as an organising principle 114 5.3 Why should we care? The bridging role of ecosystem services 115 5.4 Key research themes 116 5.5 Integrations and synthesis 118 5.6 Summary recommendations of core knowledge needs 119 6 Ta¯ngata Whenua 123 6.1 The Hauraki Gulf – Tikapa Moana context 124 6.2 Implementation 124 6.3 Treaty settlements 125 6.4 Iwi Planning Documents 125 6.5 Agency responsiveness 126 6.6 Further development 127 6.7 Strategic considerations for responding to tängata whenua values 128 6.8 Case Study 1: Tamaki River (invited contribution by Moana Tamaariki-Pohe) 128 6.9 Case Study 2: Whangamatä (invited contribution by Nathan Kennedy) 130 6.9.1 Managing Whangamatä’s cultural landscape 130 6.9.2 Maori environmental evaluation 132 7 Responses to strategic issues 135 7.1 Human impacts on the Gulf 135 7.2 Fishing impacts 137 7.3 Sediment contamination 138 7.4 Nutrients 138 7.5 Bathing beach quality 138 7.6 Sediment 139 7.7 Introduced marine species 140 7.8 Harmful algae, pathogens and mass mortalities 140 7.9 Maintenance and recovery of biodiversity 140 7.10 Coastal development 141 7.11 Integrated management 144 7.11.1 A new management response? 145 8 Discussion 147 9 Conclusions 153 10 Acknowledgements 157 11 References 159 State of the Environment Report 2011 7 Chairman’s Foreword I am pleased to introduce the Hauraki Gulf Forum’s third State of the Environment Report. We have made much progress over the past three years in building understanding of the require- ments of the Hauraki Gulf Marine Park Act 2000, since the appointment of a full-time manager. We have published four guides on implementation of the Act through policies and plans (Hauraki Gulf Forum 2009), and the use of non-regulatory tools, under the Resource Management Act (Hauraki Gulf Forum 2010a); through the Fisheries Act (Hauraki Gulf Forum 2010b); and via the process of spatial planning (Hauraki Gulf Forum 2011). The Act seeks integrated management aimed at sustaining the life-supporting capacity of the Gulf. It recognises that it is the interrelationships between water, islands and catchments that pro- vide this capacity and is a matter of national significance. Management agencies are required to protect and, where appropriate, enhance this capacity for the social, economic, recreational and cultural well-being of people and communities. This is our most ambitious report in that it attempts to respond faithfully to the Act’s require- ment for the Forum to produce every three years “a report on the state of the environment in the Hauraki Gulf, including information on progress towards integrated management and responses to [prioritised, strategic issues].” As a basis for the report a core set of indicators drawn from biophysical monitoring programmes available from agencies was used. Because the available indicator sets are limited in their scope and longevity, the report also contextualises the state of the Hauraki Gulf against historical information and knowledge about how marine systems function ecologically. This enables us to recognise the transformation which has occurred in the Gulf over two human lifespans and the incremental change which continues. The report concludes that most environmen- tal indicators either show negative trends or remain at levels which are indicative of poor environ- mental condition. The report also assesses the responses of agencies to the important issues facing the Gulf, accord- ing to their scale and potential impact, and the degree of integrated management. It concludes that there has been a collective failure to halt or reverse decline in the Gulf’s natu- ral resources. This makes for challenging reading and calls into question some of the fundamental assumptions we use when undertaking business as usual. I am pleased with the contribution by Professor John Montgomery and Dr Simon Thrush, which points out that the Hauraki Gulf is probably the best studied and known ecosystem in New Zealand, and such knowledge provides a platform for world-leading, ecosystem-based management. They suggest areas for research focus also, noting this must be rigorous and of a high quality if we are to move to effective action. In adopting this assessment for publication the Forum asked for feed back on options to address the adverse environmental impacts it identifies. I expect that this will include an expanded set of indicators which enables us to track progress towards clear targets and carefully planned interventions aimed at protection and enhancement. This is needed to ensure a rich diversity and abundance of fish and marine life in the Hauraki Gulf in the future. Mayor John Tregidga Chair Hauraki Gulf Forum 1. Executive Summary 10 Tikapa Moana – Hauraki Gulf This report measures progress toward achieving the vision of the Hauraki Gulf Forum, and consid- ers whether the life-supporting capacity and resources of the Tïkapa Moana – Hauraki Gulf are being protected or, where necessary, enhanced in accordance with the objectives of the Hauraki Gulf Marine Park Act 2000. The Forum’s vision aims for a future where environmental quality is maintained, and the Hauraki Gulf is rich in diversity, with thriving fish and shellfish (kaimoana). It also seeks to ensure that resources are used wisely to grow a vibrant economy, and to protect our cultural heritage. Humans have lived in New Zealand for only a relatively short time, but their impacts on the natu- ral environment have been profound. The degradation of the environment began with the arrival of Mäori, and was accelerated once European settlement occurred.