The Influence of the Spatial Scale on the Fishery Landings-SST Relationship

Abstract

Possible effects of the spatial scale of analysis on the relationship between fishery landings and the water temperature in the Mediterranean Sea have been investigated using the FAO capture database . The analysis was performed by dividing species in three thermal affinity categories: cold, temperate and warm-water species. Results showed significant changes in fishery landings composition during the last four decades, in terms of the relative contribution of cold, temperate and warm-water species to landings; moreover, the presence of a strong influence of water warming in determining the landings temporal pattern has been confirmed. This relationship, however, resulted to be not homogenous across the tested spatial scales (entire Mediterranean basin, three main sub-basins, eight FAO areas). The best models (based on the Akaike Information Criterion), were the ones fitted at the finer spatial definition (i.e., the eight FAO areas) for all the three thermal affinity categories. The recorded relationship showed clear differences in terms of direction, depending on both areas and thermal affinity groups. Cold-water species showed a negative relationship with the increasing water temperature in all the FAO areas, being partially replaced by temperate-water ones, with the exception of the Adriatic and Black Sea (the coldest areas in the Mediterranean basin), where a moderate increase in the water temperature is still favoring the cold affinity group. This kind of results could be useful within the context of the management plans definition, within a context of climate changes.

Age and growth of pompano, Trachinotus ovatus, from the Strait of Messina (central Mediterranean Sea)

“…In the last few years, the warming has caused fluctuations in the abundance and distribution of endemic species, as well as the settlement of some alien species (Lasram et al 2010, Albouy et al 2013, Givan et al 2018). The higher water temperature could induce reproductive and recruitment failure in cold thermal affinity species, while benefiting the reproductive cycle of warm thermal affinity species (Munday et al 2008, Pankhurst and Munday 2011, Pranovi et al 2016, such as pompano. Indeed, the pompano is becoming an important fish resource for local artisanal fisheries (Battaglia et al 2017a), as well as an alternative to former common target species, because its catches have increased alongside the decrease in other common commercial fish, such as Scombridae and Clupeidae (Azzurro et al 2011).…”

Sea Surface Temperature Variability and Marine Heatwaves in the Black Sea

“…According to [5,6], MHWs are defined as "discrete periods of abnormally warm water event that persist five days or longer with temperatures above the 90th of SST climatology threshold". Over the last decade, MHWs are becoming more regular and severe in the world's oceans and seas [3][4][5][6][7][8][9][10][11]. This leads to loss of coastal and marine habitats, stressed ecosystems, and decreased productivity, all of which have an influence on fisheries [7,12].…”

“…Over the last decade, MHWs are becoming more regular and severe in the world's oceans and seas [3][4][5][6][7][8][9][10][11]. This leads to loss of coastal and marine habitats, stressed ecosystems, and decreased productivity, all of which have an influence on fisheries [7,12]. This will have an impact on people in a region who rely on coastal and marine ecosystems for food security [12].…”

Using remote sensing indicators to investigate the association of landings with fronts: Application to the Alboran Sea (western Mediterranean Sea)

“…Despite of the relevance of landings estimates to assess the health of fisheries remains unclear (Pauly, Hilborn, & Branch, 2013), this type of data undoubtedly represents an important resource for the fishery community, and constitutes the only alternative for those regions where extensive fishery-independent surveys are unavailable. Even without spatialization, landings data can be ascribed to specific sea areas and at different spatial scales (Caddy & Carocci, 1999;Pranovi, Anelli Monti, Brigolin, & Zucchetta, 2016;Watson, Kitchingman, Gelchu, & Pauly, 2004). However, analyzing relationships among landings and relevant oceanographic features of areas to which they refer still represents a challenging task.…”