In recent years, invasive crabs have become a real problem for Spanish aquatic ecosystems. Their presence causes habitat alteration and affects native species.; Furthermore, the scientific community continues to warn about new causes for concern linked to pollution and the changes these animals cause.
Recent research has focused on how the microplastic pollution and the expansion of invasive species, such as red swimming crab (Cronius ruber) and the Chinese crayfish (Eriocheir sinensis), intertwine to aggravate the environmental impact, especially in the Canary Islands and in peninsular rivers and wetlands.
Presence of microplastics in the invasive Canary crab
A pioneering study carried out by the Ecophysiology of Marine Organisms (EOMAR) group at the University of Las Palmas de Gran Canaria (ULPGC) has documented for the first time the existence of microplastics in the crab Cronius ruber, an invasive species detected on various beaches in Gran Canaria.
The analysis included 63 specimens collected from four points on the island: Las Nieves Beach (Agaete), La Laja (Las Palmas de Gran Canaria), El Puertillo (Arucas) and Anfi del Mar (Mogán). The results showed that More than half of the crabs carried contaminant particles in their digestive system, mainly textile fibers of rayon, polypropylene, acrylic, nylon and polyester, materials that usually come from washing clothes.
Fifty-two percent of the specimens were identified as having microplastics measuring between 52 and 0,5 millimeters in length, with an average of between 0,7 and 1 particles per animal. The study also showed that 89% of this waste was fibers, mostly blue and black..
Domestic waste and its effects on invasive marine fauna
La Research indicates that proximity to wastewater discharges, especially domestic wastewater, is linked to the presence of microplastics in crabs Cronius ruber.The beaches closest to illegal dumping sites, such as Anfi del Mar and El Puertillo, showed the highest rates of microplastic contamination among the samples analyzed.
The Microplastics can filter harmful pollutants and transfer into the food web, affecting not only the invasive crustaceans, but also to all marine fauna and, ultimately, to humans.
The scientific team highlights that it is required delve into studies to understand the long-term effects from exposure to microplastics in species such as Cronius ruber and on the health of affected coastal ecosystems.
The Chinese crab and its threat in Spanish rivers
Meanwhile, on the peninsula, Eriocheir sinensis, known as Chinese or mitten crab, continues to expand and create significant challenges for environmental management. This crab, classified as an invasive species for decades, adapts to diverse conditions and has established itself in iconic locations such as the mouth of the Guadalquivir River and the Albufera de Valencia lagoon.
With catadromous habits, They alternate between fresh and salt water to complete their life cycle, which favors their dispersal. Adult males and females dig in the banks, causing erosion and destruction of river infrastructureCompetition with native species and the modification of food chains aggravate the situation.
In some places, problems have been reported such as Pipeline blockages, damage to aquaculture facilities, and harm to local fisheriesThe economic impact of these crabs increases as their population grows.
Control and monitoring of invasive species in Spain
Administrations and research groups implement specific measures to curb the spreadIn Andalusia, for example, selective capture devices are used during migrations, with special equipment to catch adults before they can reproduce in open waters.
Between 2001 and 2008, nearly XNUMX fish were caught. a thousand copies in the Port of Seville, reflecting the effort to control its population. In addition, there are Restrictions on the discharge of ballast water and awareness campaigns targeting the fishing and aquaculture sectors. Several regions, such as the Basque Country, maintain monitoring and containment programs to prevent their spread.
Future impact of invasive crabs
Researchers believe that Cronius ruber could become Bioindicator to assess microplastic pollution in the eastern Atlantic. On the other hand, the study of the Chinese crab remains essential to understanding its ecological impact and developing more effective strategies for its management.
It is essential to adopt innovative solutions and promote international cooperation to protect aquatic ecosystems, reduce damage to native species, and preserve human activities related to these natural environments.