Advancing systematic conservation planning in the Mediterranean Sea

Abstract

Marine biodiversity is globally declining due to a plethora of anthropogenic threats. Some of these threats are local, such as light pollution and coastal development, while other threats such as climate change operate at larger spatial scales. A range of conservation actions need to occur to effectively mitigate these mounting threats. Due to constraints on time and money for conservation actions we must set spatial priorities. These priorities need to achieve conservation goals and have a high chance of success. The aim of this thesis is to develop approaches that improve the spatial prioritisation of marine biodiversity conservation. Implementation of conservation plans is largely dependent on the cohesion of conservation objectives within the larger economic and social context that it lies within. In this thesis, I use the complex setting of the Mediterranean Sea to explore and propose innovative systematic prioritisation approaches. The Mediterranean Sea is a global biodiversity hotspot surrounded by over twenty countries. In this region threats to biodiversity and ecosystems are high and regional conservation plans based on systematic planning are still limited, providing an ideal system for investigating novel conservation planning approaches. This thesis is composed of seven chapters, which address three key themes for improving spatial conservation prioritisation. Chapter 1 is a broad introduction to the thesis. This chapter examines previous applications of conservation planning and prioritisation, highlighting gaps and limitations of current approaches. I introduce systematic conservation planning, applying it to the marine realm and specifically the Mediterranean Sea. Chapters 2 to 6 each present an approach to spatial conservation prioritisation relevant to protected area design in the Mediterranean Sea. The first theme (Chapters 2 and 3) explores ways to improve conservation efficiency in the marine realm. In Chapter 2 I present the first study that quantifies the increase in cost-efficiency of collaborative conservation in the marine realm. This approach can help deliver efficient conservation outcomes when planning spatially explicit actions within marine environments shared by many countries. Chapter 3 examines the importance of cost in marine conservation planning. I develop an approach for addressing cost when planning large-scale marine protected areas networks that span across multiple countries. I reveal that area is a poor cost surrogate for conservation cost in marine systems and that the most effective surrogates are those that account for multiple sectors or stakeholders. The second key theme of the thesis (Chapters 4 and 5) addresses the issue of adequately protecting species in conservation planning. In Chapter 4, I address the importance of incorporating species migration information into conservation planning. To ensure that species are adequately protected it is crucial to underpin conservation planning by the biological life-stages of species. In Chapter 5, I explore how to determine species threats using remote sensing and satellite imagery. I investigate a case study of nesting sea turtles in the eastern Mediterranean, and show that artificial night lights can affect their spatial nesting patterns. This study reveals the importance of satellite night-time imagery for conservation purposes. It also defines the first step of any conservation plan that strives to adequately protect species from threatening processes. The third theme (covered in Chapter 6) aims to improve implementation success. Chapter 6 applies systematic zoning tools to a country’s entire territorial waters, aiming to protect biodiversity when faced with multiple marine activities. Specifically, I quantify the trade-offs between conservation and economic objectives. The case study in this chapter is relatively complex, allowing for multiple zones and costs; it shows that prospective offshore hydrocarbon resources can have a very large influence over conservation plans. Finally, Chapter 7 is a synthesis of the thesis. I address the contributions of this research towards advancing marine conservation prioritisation both in the Mediterranean region and globally. Unifying my findings from this thesis, I propose additional steps to improve the framework of systematic conservation planning when applied to the marine realm. This thesis advances the theory of marine prioritisation, but also delivers practical outcomes, providing the first large-scale prioritisation of conservation actions for the Mediterranean Sea. Overall, this research advances our knowledge of conservation prioritisation in the marine realm. It provides strategies and methods to improve systematic conservation planning efficiency, adequacy and implementation success. This thesis focuses on how to make good decisions regarding the selection of marine protected areas (MPAs) and priority areas for marine conservation in the Mediterranean Sea that can have implications for many other parts of the world.