Invasive American weakfish found in Algarve “could be opportunity, not threat”

An invasive species of American weakfish (‘corvina norte-americana’) found in Algarve waters in 2016 and once viewed as an “ecological threat” could, in fact, be an “economic opportunity” if it is added to locals’ diets, a study has found.

“By catching it, humans as apex predators can help control this imbalance in the ecosystem, as American corvina is a fishing resource that can and should be valued,” senior researcher Alexandra Teodósio from the University of the Algarve (UAlg) told Lusa news agency.

The weakfish (Cynoscion regalis) is a marine fish native to the east coast of North America and was detected for the first time in the Algarve in 2016 by fishermen in the Guadiana estuary in Vila Real de Santo António. The species was later formally identified by researchers from UAlg’s Centre of Sea Sciences (CCMAR).

“There is potential to develop fishing practices directed at controlling the abundance of this invasive species,” said the researcher, adding that the weakfish is already sold in some markets in the south of Portugal albeit at a low market price.

“This non-native species is sold for a price ranging between €3 and €5 per kilo, but its sale can be promoted in order to provide more profit for fishermen,” Teodósio said.

The fishing of weakfish could “even be beneficial to the recovery of native resources which are being overfished. As the researcher explained, this is a “voracious” species that feeds off of “nearly every resource possible”, from bivalves to the traditional corvina – a relative species.

The study found that Portuguese consumers are receptive to introducing the weakfish into their diets and willing to pay up to €9.5 per kilo for it.

“It was the price set by respondents, and we can conclude that there is great potential to implement a fishing programme, while at the same time reducing the numbers of this species and thus minimise its impact on our coast,” the researcher said.

The study also found that respondents would prefer to buy weakfish – a wild marine fish – than fish produced in fish farms, such as sea bass and white seabream.

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