Opportunities from citizen science for shark conservation, with a focus on the Mediterranean Sea

Abstract

The Mediterranean Sea is a hotspot for shark conservation. A decline in large pelagic shark populations has been observed in this vast region over the last 50 years and a lack of data on the local population status of various species has been pointed out. Throughout history, the relation between people and sharks has been revolving around a mixture of mystery, fear, and attraction. Recently, however, a remunerative ecotourism industry has been growing in areas of shark aggregation globally. This growth has been accompanied by the establishment of a citizen science (CS) movement aimed to engage and recruit ecotourists in data collection for shark research. Several CS projects have generated interesting results in terms of scientific findings and public engagement. In the Mediterranean Sea, shark aggregations are not as relevant to support locally-focused CS actions on shark diving sites as in other parts of the world. However, a series of other initiatives are taking place and CS could offer an excellent opportunity for shark conservation in the Mediterranean Sea. The dramatic decline of shark populations shown in the region calls for alternative ways to collect data on species distributions and abundance. Obtaining such data to set proper conservation and management plans for sharks in the Mediterranean Sea will be possible if existing CS initiatives collaborate and coordinate, and CS is widely acknowledged and deployed as a valuable tool for public education, engagement, and scientific discovery. After providing an overview of multiple facets of the relationship between humans and sharks, we focus on the possibility of exploiting new technologies and attitudes toward sharks among some groups of ocean users to boost participatory research. CS is a great opportunity for shark science, especially for areas such as the Mediterranean Sea and for large pelagic sharks whose populations are highly impacted.

Sandbar shark aggregation in the central Mediterranean Sea and potential effects of tourism

“…Indeed, the successful protection of endangered, highly mobile species should rely on the ability to characterize their aggregations in space‐use hotspots, to track their large‐scale movements, and to combine transnational and local conservation actions, including the reduction of the anthropogenic impacts. Likely, an increased awareness of Mediterranean shark stock depletion (Bargnesi, Lucrezi & Ferretti, 2020) has recently led to the collection of quantitative and qualitative information on Mediterranean shark space‐use hotspots. The existing knowledge on the Mediterranean aggregations of C. plumbeus comes from a few studies carried out at Boncuk Bay in the southern Aegean Sea (Turkey) where, on average, a maximum of five individuals per hour were recorded using underwater visual census transects (Filiz, 2019).…”

A shot in the dark for conservation: Evidence of illegal commerce in endemic and threatened species of elasmobranch at a public fish market in southern Brazil

“…The overfishing of sharks is problematic, and a number of recent reports have indicated a marked reduction in the stocks of many species, which has often resulted in a demographic collapse at a regional scale (Davidson, Krawchuk & Dulvy, 2016; Taylor et al, 2016; Brown & Roff, 2019; Bargnesi, Lucrezi & Ferretti, 2020). In 1999, the Food and Agriculture Organization (FAO) formally recognized the vulnerability of sharks and rays, and launched an international plan for their conservation and management (Vannuccini, 1999).…”

MEDLEM database, a data collection on large Elasmobranchs in the Mediterranean and Black seas

“…Greater attention to accidental catches occurring in the various parts of the Mediterranean should be given and a more systematic recording of these opportunistic events should be facilitated. Several initiatives are taking place in the Mediterranean Sea: integration and coordination among them is pivotal (Bargnesi et al, 2020).This would make the MEDLEM database a more comprehensive tool that would not only enhance a pro-active collaboration among the various research institutes, but also represents an important source of information contributing to the improvement of our knowledge on the biology of these fishes, enabling the assessment of the status of the elasmobranchs and, lastly, the promotion of better conservation measures.…”