Management opportunities for elasmobranchs in the Mediterranean Sea: A pragmatic approach to a complex topic

Marine fisheries are a vital source of economic and food security. At the same time, unsustainable fishing practices continue to threaten species at alarming rates. Elasmobranchs (sharks and rays) are among the species most threatened by fisheries and are among the most threatened vertebrates globally. Among some species, even slight pressure can cause declines, due to life history traits such as slow growth, late maturity, and low fecundity. The heightened vulnerabilities are exacerbated as their global range, and large size at birth, makes them vulnerable to a range of fishing gears, from diverse habitats, throughout their lives. While some elasmobranchs are exploited for commercial use, they are rarely classified as target catch, as a result their management has long been neglected. While there has been an increasing focus towards their declines, and success stories of sustainable fisheries, the latter remain concentrated in few regions, amidst continue declines in others. The Mediterranean Sea fits the latter, where elasmobranch populations face serious declines. This dissertation used the Mediterranean regulatory framework as a backdrop for which to investigate how might practical measures be applied to improve elasmobranchs and fisheries. While the Mediterranean served as case study for the managerial and policy considerations, the Italian waters direct data applications and field work. Within the region, geopolitical and socioeconomic considerations are significant and there is a resulting overlapping governance framework, with many state, regional, international, and non-governmental actors. To being, I described the current framework, tools, and policies, that could directly or indirectly be applied to elasmobranchs. In doing, I considered the strength of measures that were directly applicable, for example, species measures for protected or regulated species, as well as indirect, such as fisheries closures that overlapped with species’ ranges. I also looked to countries inside and outside the European Union (EU), whose legislation is shared, in order to understand management barriers. Largely, there are inconsistencies among compliance and enforcement. But most importantly, the framework to support elasmobranch management is mostly complete in the Mediterranean. Rather than creating new frameworks and introducing new measures, there should be a collaborative focus towards working within the system. Next, I wanted to examine why data is so scarce for elasmobranchs in the region, and in Italian waters. To this end, I acquired data from national Logbook and Observer programs, and landings data from a market. I aimed to reconstruct the catches in the Italian geographical subareas (GSAs) from the sources. Using the relative compositions, I evaluated the complementary nature of the sources, especially with respect to the fisheries collected data. Reconstructing the catch of each source revealed a different picture. The Logbook informed in many more species, including some rare ones, and maintained a stable composition over the years examined. The Observer data was more stochastic, which follows from the restrictions in time and space (onboard coverage is only ~0.5%). The Observer data provided much finer resolution, at an individual level, and reported discards. Market data, reported as species groups, was useful to understand the landings and commercial species. Taken together, the Logbook and Observer programs revealed species identification problems, and some aggregated reporting that could be solved through improved communication. Ultimately, the need to increase onboard Observer coverage and standardise reporting will be crucial to produce complementary data that can support stock assessment and direct management.