Communicating Marine Environmental Health: Connecting Science, Social and Policy Values

Human activities are degrading marine ecosystems and undermining the ecological functions and processes which provide valued goods and services. European and UK marine policy developments aim to implement the Ecosystem Approach to support better management of activities and maintain the health of regional seas. Current public perceptions of the UK marine environment are overwhelmingly negative, creating a barrier to engaging society with marine environmental issues and policy. This thesis conducts a study of the attributes of a suite of 72 UK marine species to identify those which contribute most to marine ecological health. The findings show that structurally complex species are most important and are recommended as species to assess and monitor Good Environmental Status as defined by the EU Marine Strategy Framework Directive. Existing conservation policies are biased towards large vertebrate species, with ecologically important species being underprotected. A survey of public perceptions of the marine environment. revealed conflicting perceptions of charismatic megafauna. Charismatic species were the most interesting species but least important as measures of marine health. Ecologically important species were the least interesting, but ecological health concepts were considered important measures of marine health. Perceptions of the marine environment varied with socio-demographic and social value factors. By integrating these studies, barriers and opportunities to engaging society with the marine environment were identified. Communication strategies which address these are proposed, including a suite of Spokes Species, potential high profile species to champion the marine environment. These include puffin, cod, basking shark and seagrass. A series of themes are proposed which implement other key findings such as the importance of personal experience in building connections with marine species. Communication strategies are supported by ecologically defined assessments of marine environmental health, are relevant to current policy developments and will resonate with social values of the marine environment

Perfect refiners for permutation group backtracking algorithms

We therefore thank the VolkswagenStiftung (Grant no. 93764 ) and the Royal Society (Grant code URF\R\180015) again for their financial support of this earlier work. For financial support during the more recent advances, we thank the DFG (Grant no. WA 3089/9-1) and again the Royal Society (Grant codes RGF\EA\181005 and URF\R\180015 ).Backtrack search is a fundamental technique for computing with finite permutation groups, which has been formulated in terms of points, ordered partitions, and graphs. We provide a framework for discussing the most common forms of backtrack search in a generic way. We introduce the concept of perfect refiners to better understand and compare the pruning power available in these different settings. We also present a new formulation of backtrack search, which allows the use of graphs with additional vertices, and which is implemented in the software package VOLE. For each setting, we classify the groups and cosets for which there exist perfect refiners. Moreover, we describe perfect refiners for many naturally-occurring examples of stabilisers and transporter sets, including applications to normaliser and subgroup conjugacy problems for 2-closed groups.Publisher PDFPeer reviewe

Computing canonical images in permutation groups with Graph Backtracking

We describe a new algorithm for finding a canonical image of an object under the action of a finite permutation group. This algorithm builds on previous work using Graph Backtracking, which extends Jeffrey Leon's Partition Backtrack framework. Our methods generalise both Nauty and Steve Linton's Minimal image algorithm.Comment: This is a revised version as re-submitte

Permutation group algorithms based on directed graphs

Funding: The authors would like to thank the DFG (Grant no. WA 3089/6-1) and the VolkswagenStiftung (Grant no. 93764) for financially supporting this work and projects leading up to it. The first and third authors are supported by the Royal Society (Grant codes RGF\EA\181005 and URF\R\180015).We introduce a new framework for solving an important class of computational problems involving finite permutation groups, which includes calculating set stabilisers, intersections of subgroups, and isomorphisms of combinatorial structures. Our techniques are inspired by and generalise 'partition backtrack', which is the current state-of-the-art algorithm introduced by Jeffrey Leon in 1991. But, instead of ordered partitions, we use labelled directed graphs to organise our backtrack search algorithms, which allows for a richer representation of many problems while often resulting in smaller search spaces. In this article we present the theory underpinning our framework, we describe our algorithms, and we show the results of some experiments. An implementation of our algorithms is available as free software in the Graph Back tracking package for GAP.Publisher PDFPeer reviewe