American crabs found in the Guadiana


Researchers at the Center for Marine Sciences (CCMAR), at the University of the Algarve, discovered several specimens of blue crab in the Guadiana River estuary, a species of high commercial value, characteristic of North America. The discovery was released this week.

CCMAR carries out research in the fields of oceanography, marine biology, fisheries, aquaculture, ecology and biotechnology and has approximately 250 members, 110 of whom are PhDs.

The species (Callinectes sapidus), also known as “crab”, considered a delicacy, is actually native to the east coast of America and was, to the surprise of researchers, first found in the Guadiana, more than seven thousand kilometers away of its original habitat. The species was found in June, and surprised local fishermen more, CCMAR said in a statement.

According to the research center, there are records of other specimens of the same species, previously caught in the Sado estuary, which indicates that “it will be in a phase of expansion on our coast, after having probably navigated, as a larva, in the ballast water of a ship that crossed the Atlantic”.

The emergence of invasive species in the Guadiana estuary has been increasing in recent years, with more than a dozen recorded species, including fish, clams, jellyfish, shrimp, and more recently this crab, “which can have dire consequences” for native species, warned the CCMAR statement.

But commercially valuable invasive species, such as the blue crab or the royal crab (Cynoscion regalis), recorded in the previous year, “may be an example of how a threat can turn into an opportunity for exploitation”, he said. CCMAR.

Therefore, given the lack of natural predators of these invasive species, “their fishing will contribute to the control of their density”, alleviating the pressure to exploit traditional fishing resources such as sardines, they added.

“New alternatives for consumption of this type of species are also being studied with chefs from restaurants in the Algarve”, concludes CCMAR, adding that its researchers are available to develop “technological and scientific partnerships with any sector of the fishing industry”.