Shifting Baselines in Coastal Ecosystem Service Provision
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Shifting Baselines in Coastal Ecosystem Service Provision By: Samiya Ahmed Selim A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy The University of Sheffield Faculty of Animal and Plant Sciences Department of Biological Sciences October 2015 1 ABSTRACT Coastal ecosystems provide vital suites of ecosystem services: food security, livelihoods, recreation, at global (e.g. climate regulation), regional (e.g. commercial fisheries) and local scales (e.g. recreation). The composition of these suites of services has clearly changed over time, as ecosystems have responded to natural and anthropogenic changes. Exploitation of these coastal ecosystems goes back centuries and many systems today are under stress from multiple sources including overfishing, pollution and climate change. Management strategies and policies are now focused on reversing these kinds of adverse effects and on restoring systems back to their ‘natural’ state. However, many of the changes that have occurred predate environmental surveys. It is difficult to set reference points and to define management policies when baselines on how ‘natural’ the system are constantly shifting. These shifting baselines mean that what we consider to be a ‘healthy’ ecosystem, with ‘optimal’ levels of Ecosystem Service provision, often lack historical context. A historical approach provides one means to parameterise such relationships. In this study I use the Yorkshire Coast of the North Sea as a case study to understand the links between drivers of change, ecosystem and the services they have provided over time. In this thesis, findings from interviews with stakeholders and from modelling long term data suggest that use of such historical data sources gives new insight into socio-ecological changes that occurs over time. It showed that there are shifting baselines and trade-offs in ecosystem services which can feed into management of future ecosystem services. It highlighted how fishermen’s perspective on changes in species and ecosystem match scientific survey data for some species, but there are shifting baselines in perceived changes. Findings on role of biodiversity in cultural ecosystem service show that it serves more of a supporting role as part of the wider seascape, rather than as recreational value related to specific aspects of biodiversity. 2 ACKNOWLEDGEMENTS This Thesis was made possible by Natural Environment Research Council (NERC) Doctoral Training Grant awarded to me and additional financial funding from CASE Partner North Eastern Inland Fisheries and Conservation Authorities (NEIFCA). I would like to thank both for their generous support. I would also like to thank Yorkshire Wildlife Trust for letting me use their online survey data for my work on cultural ecosystem services. I would like thank my supervisors Tom Webb, Julia Blanchard and Phil Warren for their guidance, insight, and understanding through the trials and tribulations of PhD life the past four years. It can be quite a juggle managing academic life whilst looking after two young children and they have always been supportive of my fluctuating time management whilst believing in the progress of my work. Thanks to Julia for introducing me to various networks and collaborators, many of which have proved fruitful and helped to get my first paper published. Special thanks to Tom for his patience and support for when I struggled through aspects of my work that were challenging and for believing that I could finish off my PhD remotely the last 6 months. I appreciate you pushing me through to the end! Thanks to my E-floor mates for a memorable and fun first year – Dan, Emily, Chris, and Anna. BIG THANK you to Anna for all your help with R the past few months! Thank you to Abi, appreciate you providing Max a loving home and will always look back and smile in exasperation at our struggles with acquiring North Sea Effort data. Where would I have been without my ever supportive PhD mates, my Gatsby partners in crime – Marjorie, Isabel, and Jenny – whom I have shared the frustrations, despairs, joys and fun of PhD life the past 4 years. Indebted to my friends and family spread across the globe, my loving father and my awesome sister who have believed in me and kept reminding me I could do this, especially when things were down. To my own family – my amazing and supportive husband Ashique and wonderful kids Shahaar and Shama – this would not have been possible without all your support (and your cooking), patience (for me to finish) and love. In the kids own words – Mama is saving all the fish in the world with her PhD, adding now and again - when am I going to ever get a real job and not be a student! This is a small excerpt from my mother’s last letter to me October 15th, 2004. I dedicate this to you Ammu. This has always been for you. 3 DECLARATION Related Publication - Chapter 2 has been published in Regional Environmental Change. The current citation is: Selim SA, Blanchard JL, Bedford J, Webb TJ. 2014. Direct and indirect effects of climate and fishing on changes in coastal ecosystem services: a historical perspective from the North Sea. Regional Environmental Change. In chapter 5 I have used survey data using an online questionnaire on cultural ecosystem services administered by Yorkshire Wildlife Trust. I have their permission to use this data for analysis with due reference In chapter 3 I reproduced images from two websites with prior permission from both sources - Amoret Tanner - fotoLibra and Callum Roberts – Unnatural History of the Sea 4 Contents CHAPTER 1 INTRODUCTION .................................................................................................................... 9 1.1 Background ....................................................................................................................................... 9 1.2 From biodiversity and 'ecosystem state' to ecosystem services .................................................... 10 1.3 Long term changes in marine ecosystems ...................................................................................... 11 1.3.1 Shifting baselines and defining ‘natural’ ecosystem states ..................................................... 12 1.3.2 Historical marine ecology and sources of historical data ........................................................ 13 1.4 Gaps in the knowledge.................................................................................................................... 15 1.4.1 Historical knowledge and shifting baselines in ecosystem services ........................................ 15 1.4.2 Links between biodiversity and ecosystem services................................................................ 15 1.4.3 Socio-ecological coupling and future marine ecosystem services........................................... 16 1.5 Thesis aims ...................................................................................................................................... 16 1.6 Thesis outline .................................................................................................................................. 17 1.6.1 Chapter 2 Drivers of change and their effects on fisheries ..................................................... 17 1.6.2 Chapter 3 - Characterizing historical changes in marine ecosystem services ......................... 17 1.6.3 Chapter 4 - Local ecological knowledge from Yorkshire fishermen over a period of 60 years 1.6.4 Chapter 5 - Role of biodiversity in cultural ecosystem services as perceived by local visitors/tourists ................................................................................................................................. 18 1.7 Rationale for case study of the North Sea along Yorkshire Coast, England.................................... 18 CHAPTER 2 DIRECT AND INDIRECT EFFECTS OF CLIMATE AND FISHING ON CHANGES IN COASTAL ECOSYSTEM SERVICES – A HISTORICAL PERSPECTIVE FROM THE NORTH SEA..................................... 20 2.1 Introduction .................................................................................................................................... 20 2.1.1 Drivers of change in coastal ecosystems ................................................................................. 20 2.1.2 Classification of coastal ecosystem services ............................................................................ 20 2.1.3 Using history to understand the causal links between drivers, ecosystem and services ........ 21 2.2 Methods and materials ................................................................................................................... 21 2.2.1 Study region ............................................................................................................................. 22 2.2.2 Sources of data ........................................................................................................................ 23 2.2.3 Statistical analysis .................................................................................................................... 26 2.3 Results ............................................................................................................................................. 28 2.3.1 Full time series ......................................................................................................................... 28 5 2.3.2 ‘Fishing’ vs ‘climate’ regimes ..................................................................................................