Mapping hotspots of undersized fish and crustaceans may aid sustainable fishing practices

February 05, 2021

A new study in Frontiers in Marine Science provides a first-of-its-kind evaluation of which regions of southern European seas are in the most need of fishing restrictions. These areas have persistently shown high numbers of undersized fish and crustaceans, which are typically discarded because they are below the allowable size limit for collection. These findings may offer a strategy for prioritizing conservation efforts and ensuring more sustainable fishery management in the future.

"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," says lead author Dr Giacomo Milisenda, of the Stazione Zoologica Anton Dohrn di Napoli in Italy. "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."

According to a draft report from the European parliament in early January, Europe is far from reaching its marine sustainability and biodiversity goals. Despite the aims of the recently reformed EU Common Fishery Policy and commitments made by the European Commission, overfishing, habitat destruction and excessive discarding of unwanted catches are still ongoing problems.

The latest report from the Food and Agriculture Organization (FAO) of the United Nations found that 75% of Mediterranean and Black Sea fish stocks are overfished. Furthermore, past research has shown that, globally, more than 40% of catches are thrown back. The FAO has also found that roughly 50% of the discarded fish from the Mediterranean Sea is the result of demersal trawling -- a method of dragging nets across the sea floor.

To identify the regions that regularly have high proportions of unwanted catches, Milisenda and his collaborators combined bottom trawling surveys with the itineraries of commercial fishing operations from the last 15 years. They focused on four of the most important fishing waters in the area: the continental Portuguese coast, Catalan Sea, South of Sicily and Liguria and northern Tyrrhenian Seas.

Their findings showed that there were patches that were repeatedly trawled, and that these locations frequently coincided with hot spots of undersized animals. These methods may also make it possible to predict and avoid zones that are likely to have too many of these smaller animals.

In response to January's European parliament draft report, a coalition of NGOs has issued an urgent call for additional resources to safeguard European waters. The General Fisheries Commission for the Mediterranean has already been promoting fishing restrictions that prioritize which regions to protect and Milisenda's findings may help better plan current and future fishing operations.

The authors hope that their research will be used by governments and fishing operations to help address these ongoing environmental emergencies.

"Spatial management can only be successful if it is combined with the active collaboration of stakeholders (fishermen) and an effective regulation plan," says Milisenda.


Related Fisheries Articles from Brightsurf:

Assessing El Niño's impact on fisheries and aquaculture around the world
New report presents the main regional consequences caused by the five types of the climate pattern.

Dissolved oxygen and pH policy leave fisheries at risk
In a Policy Forum, ''Dissolved oxygen and pH criteria leave fisheries at risk'' published in the April 24 issue of the journal Science, Stony Brook University's Dr.

Fisheries management is actually working, global analysis shows
Nearly half of the fish caught worldwide are from stocks that are scientifically monitored and, on average, are increasing in abundance.

Meeting the challenges facing fisheries climate risk insurance
Insurance schemes with the potential to improve the resilience of global fisheries face a host of future challenges, researchers say.

Healthy mangroves help coral reef fisheries under climate stress
Healthy mangroves can help fight the consequences of climate change on coral reef fisheries, according to a University of Queensland-led study.

Study champions inland fisheries as rural nutrition hero
Researchers from MSU and the FAO synthesize new data and assessment methods to show how freshwater fish feed poor rural populations in many areas of the world.

For global fisheries, it's a small world after all
Even though many nations manage their fish stocks as if they were local resources, marine fisheries and fish populations are a single, highly interconnected and globally shared resource, a new study emphasizes.

New study maps how ocean currents connect the world's fisheries
It's a small world after all -- especially when it comes to marine fisheries, with a new study revealing they form a single network, with over $10 billion worth of fish each year being caught in a country other than the one in which it spawned.

Federal subsidies for US commercial fisheries should be rejected
A pending rule change proposed by the US National Marine Fisheries Service would allow the use of public funds to underwrite low-interest loans for the construction of new commercial fishing vessels.

Sustainable fisheries and conservation policy
There are roughly five times as many recreational fishers as commercial fishers throughout the world.

Read More: Fisheries News and Fisheries Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to