New discovery of biological invasions: the recent arrival of the Mediterranean parrotfish and the Atlantic blue crab to the Portofino Marine Protected Area highlights the ongoing transformation of our seas under the growing pressures of climate change and invasive species.
A recent scientific training held in the Marine Protected Area (MPA) of Portofino has documented two noteworthy species observations, providing further evidence of biological invasions and the ongoing ecological change in the northern Mediterranean: the Mediterranean parrotfish (Sparisoma cretense) and the Atlantic blue crab (Callinectes sapidus).
These findings, although based on isolated observations, represent significant records for both the Ligurian coast and the broader northern Mediterranean. They contribute to documenting the ongoing transformation of Mediterranean biota, as native warm-water species, such as the Mediterranean parrotfish, expand into northern regions, and invasive species, like the Atlantic blue crab, increase in both abundance and distribution.
Monitoring climate change impacts at Portofino Marine Protected Area
The Portofino MPA, one of Italy’s most iconic marine reserves, continues to serve as a living laboratory for monitoring the effects of climate change and biological invasions, two increasingly interconnected challenges in Mediterranean marine ecosystems.
From May 12 to 15th, six participants led by experts in climate change adaptation gathered in Portofino as part of the MPA4Change Training programme on climate change adaptation in Marine Protected Areas dedicated to Monitoring Protocols. During the training, participants were able to put into practice protocols for assessing mass mortality of corals, fish populations, install underwater temperature loggers, integrate local stakeholders´ knowledge and data sharing – see full article on Portofino training.
The Mediterranean parrotfish
Juveniles of Mediterranean parrotfish (Sparisoma cretense) found in Portofino MPA waters – Photo by H. Cizmek.
The sighting of Mediterranean parrotfish (Sparisoma cretense) was recorded during an underwater visual census training on climate change indicators and was documented in a photograph taken by one of the participants. This sighting of biological invaison marks an unusual observation within the Portofino MPA, confirming its continued northward expansion likely driven by rising sea temperatures.
This herbivorous species is typical of the southern and warmest sectors of the Mediterranean, as well as the subtropical Atlantic, where it inhabits shallow rocky coastal waters. Outside the Mediterranean, it is commonly found from Portugal to Senegal, including the Canary Islands, Azores, Madeira, and Cape Verde, where it is highly valued for its meat
The Atlantic blue crab
Blue Crab (Calinectes sapidus) on shoreline – Photo by John J. Mosesso (Public domain)
In contrast, the Atlantic blue crab (Callinectes sapidus) was never recorded before in the Portofino MPA. Reported by a local small-scale fisher participating in a Local Ecological Knowledge (LEK) monitoring activity and photographed by the same fisher after its capture.
The Atlantic blue crab is native to the Atlantic coast of the Americas and it is being increasingly reported along European shores. This invasive crab is known for its dramatic ecological and economic impacts in Italy and in other European and Mediterranean countries. Its first detection within the MPA raises concerns about potential establishment in this ecologically sensitive habitat, although the absence of lagoons and freshwater inputs in the area may limit its reproductive success.
About MPA4Change Monitoring Toolkit
MPA4Changte Monitoring Toolkits are a validated way to assess climate change impacts on the marine envrironment and comprise a set of protocolos focusing on different habitats and species. You can learn more about the protocols in the Training programme on climate change adaptation in MPAs webpage.
