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ICES WGEF recommends that demersal elasmobranchs be managed using spatial proxies 11 for Maximum Sustainable Yield. Here we combine escapement biomass – the percentage of the stock which must be retained each year to conserve it – with maps of predicted abundance of four ray species (cuckoo, thornback, blonde, and spotted), created using Boosted Regression Tree modelling. We then use a Decision Support Tool to generate location and size options for MPAs to protect these stocks, based on the priorities of the various stakeholders, notably the minimisation of fishing effort displacement. Variations of conservation/fishing priorities are simulated, as well as differential priorities for individual species, with a focus on protecting nursery grounds and spawning areas. The result is a complete software package that produces maps of predicted species abundance from limited survey data, allowing disparate stakeholders and policymakers to discuss management options within a mapping interface. No

Skates and rays represent one of the most vulnerable components of fish communities in temperate demersal fisheries such as the Irish Sea. They also tend to be data poor in comparison to commercially exploited teleost fish. Spatial management has been suggested as an important tool to protect these species, but requires an understanding of the abundance distribution, and the relationship the abundance distribution has with the environment at both adult and juvenile life history stages. Here we modelled bottom trawl survey data using delta log-normal boosted regression trees on to derive rays’ spatial abundance, and environmental links. The modelling approach allowed the development of high resolution predictive maps of abundance of four skate and ray species targeted by fishing activity: thornback, spotted, cuckoo and blonde rays. The distributions of these species were driven by a general preference for sand and coarser substrates as well as higher salinities, temperatures and currents speeds. Spatial comparisons between abundance distributions and locations of skate and ray commercial landings indicated that the main hotspots for the investigated species are outside of the main commercial fishing areas and overlap with potential MPAs proposed for wider ecosystem protection. The method offers a useful tool for selecting potential MPA’s to assist the management and conservation of data-poor species. Yes

Increased demand for abalone and sea urchins globally has resulted in increased production of these commercially important invertebrates in aquaculture. Transfer of aquaculture technology from established producing countries to Europe has resulted in the application and implementation of new technologies by farm operators in Ireland. The industry-based research presented in this thesis addresses key industry barriers in invertebrate aquaculture, focusing on production and on-growing methods for the European abalone Haliotis tuberculata and the commercially important native sea urchin Paracentrotus lividus. To resolve knowledge gaps in the production of algivorous invertebrates in Ireland four main issues were investigated: 1- Industry, market and production constraints for the non-endemic species of abalone H. tuberculata and H. discus hannai were reviewed and evaluated. Findings indicated the current status and direction of the culture of abalone in Europe. 2- New culture methods were developed for the green encrusting macroalgae Ulvella lens as it is known to increase settlement rates of swimming abalone and sea urchin larvae. Both abalone and sea urchins have similar preferences to settlement cues and the technology for settlement is common to both industries. Ulvella lens has been used and implemented successfully into the abalone industry in producing countries such as Japan and Australia. 3- Culture methods developed for U. lens were applied to the P. lividus culture with the aim of implementing this developed technology into sea urchin aquaculture in Ireland. Due to the decline of the commercial P. lividus fishery in Ireland, increased interest has developed in the commercial culture of this species. The findings of this industry-based research indicate the need for increased commercial scale research addressing the production constraints that hamper the industry as a whole. 4- Novel mixed macroalgal-meal diets enriched with bioavailable phosphorus were investigated for increased growth in the diet of H. tuberculata, and compared against Palmaria palmata. Weaning diets for juvenile abalone normally incorporate some form of animal protein, which does not belong in the natural diet of juvenile abalone as they are algivorous by nature. Phosphorus is limiting in the diets of abalone, and may not be available as it is bound in an indigestible form such as phytate.

Supervised by Dr Colm Lordan & Dr Rick Officer. Submitted to the Higher Education and Training Awards Council, July 2013, It is widely acknowledged within the scientific community that a single species approach to European mixed fisheries can result in species-specific advice inconsistent with multi-species management objectives. Within the reformed Common Fisheries Policy a move toward mixed fisheries and ecosystem based management is encouraged. The overall objective of this research was to improve understanding of the complex targeting behaviour undertaken by commercial fishers. Whereby, improved understanding will enhance the ability to predict the responses to future mixed fisheries management measures and changing economic conditions within the Irish fishing industry. Irish métiers (groups of homogeneous fishing trips) highlight the complexity of fishing activities within the Irish fleet, having identified 33 otter trawl métiers and 19 in the remainder of the fleet. Métier dynamics identified over compensation to introduced management, resulting in effort displacement and increased temporal specific fishing pressure. Therefore were deemed as appropriate base units for all subsequent analyses. Two economic variables, operational fishing cost and trip landings value, considered to represent important drivers were developed. This lead to application of a general additive model to estimate and predict fuel consumption estimates according to fleet segment definitions. A linear mixed effects model with random vessel effect was developed as a method of standardising value generating an index of value per unit effort. This identified kilowatt fishing days as the most appropriate effort measure. The final investigation stage successfully amalgamated the knowledge gained into the formulation of novel Markov transition probability for a multinomial model to predict fisher métier strategy choice. This is to be incorporated into management strategy evaluation, aiding the assessment and possible impacts of future management proposals on the Irish fleet and commercial stocks around Ireland. Developments presented will benefit the progression toward optimising sustainability within a mixed fisheries approach to management through incorporation of economic considerations.