By mapping where undersized fish and crustaceans are congregated, researchers hope to help fisheries managers better protect vulnerable fish and crustacean stocks.
In a paper, published Friday in the journal Frontiers in Marine Science, researchers pinpointed a variety of hotspots for undersized fish and crustaceans in southern European seas — areas where stronger fishing restrictions are warranted.
The mapping efforts could be repeated elsewhere to identify regions where overfishing risks and large juvenile fish populations overlap.
"Natural fish populations need time to reproduce and recover from fishing impacts — this is the only way to achieve a balance between natural resources and human exploitation," lead study author Giacomo Milisenda said in a news release.
"Our findings provide evidence supporting active spatial-based management, such as the designation of Fisheries Restricted Areas [FRAs] in order to minimize the capture of immature or undersized specimens and improve the sustainability of demersal — that is, sea floor — fisheries," said Milisenda, a scientist with the Stazione Zoologica Anton Dohrn, a research institute in Naples, Italy.
Despite pledges from the European Union's member states to take actions to curb overfishing, slow habitat destruction and reduce unwanted catches, recent reports suggest Europe is falling short on a variety of marine sustainability and biodiversity goals.
Recent reports by the United Nations show more than a third of the world's fish stocks are overfished — in the Mediterranean and Black Sea, roughly 75 percent of fish stocks are overfished.
Around the world, commercials fishers throw back approximately 40 percent of their catch. In the Mediterranean, at least half of the unwanted catch is caused by bottom trawling, a damaging practice that involves dragging nets across the seafloor.
Unwanted catch includes both fish that aren't commercial targets and target fish that are too small to meet regulations.
For the new study, researchers surveyed trawling data and unwanted catch reports to isolate regions where undersized fish and crustaceans are concentrated.
The new analysis revealed several regions important to juvenile fish and crustaceans: the Portuguese coast, Catalan Sea, South of Sicily and Liguria and northern Tyrrhenian Seas.
Despite the rich concentrations of young fish and crustaceans, trawling remains common in these areas.
Researchers hope their findings will inspire European Parliament and fisheries managers to take aggressive action to limit fishing in these areas.
"Spatial management can only be successful if it is combined with the active collaboration of stakeholders [fishers] and an effective regulation plan," said Milisenda.
