An international scientific team, led by the Spanish Institute of Oceanography (IEO-CSIC), has confirmed a finding that has put the biological community on alert: the presence of the red macroalga Asparagopsis taxiformis on the Galician coastThis discovery, which has already been documented in the specialized publication Bioinvasions Records, is based on the location of a specimen in the RÃas Baixas during the year 2025, which represents a drastic change in what we knew about its geographical expansion.
The significance of this scientific finding is considerable, as it represents the northernmost record of this species along the entire European Atlantic coast. In fact, its detection in Galician waters implies extend by more than 500 kilometers The previously known distribution limit, which was located in southern Portugal, has been extended. This northward shift indicates that the natural barriers that once held back these tropical organisms are beginning to weaken in the face of changes in the marine environment.
Molecular identification of an invasive variant
Following the discovery of the specimen, researchers conducted exhaustive genetic analyses to determine exactly which variant it was. The molecular results confirmed that it is the called lineage 2 of the speciesThis genotype is of particular concern to biologists due to its remarkable ability to propagate and its extremely high tolerance to diverse environmental conditions. This genetic robustness is clearly what allows an alga from warm climates to survive and establish itself in the traditionally cooler waters of the Galician coast.
Eva Cacabelos, a researcher at the Vigo Oceanographic Center and a key figure in this study, has indicated that for now it is a population that appears to be incipientThis conclusion is drawn from the lack of reproductive structures in the analyzed individual, suggesting that it has not yet massively colonized the substrate. However, we must remain vigilant, as its mere presence is already a clear symptom of how global warming and incessant maritime traffic are altering the landscape of our ecosystems.
Water heating as a driver of change
The arrival of this macroalga, native to the Indo-Pacific region and which has already wreaked havoc in the Mediterranean and southern Spain, is not an isolated event. Experts link this migratory movement directly to the thermal increase of water masses and the frequency of marine heatwaves, factors that weaken the defenses of native biodiversity. When the sea warms, a window of opportunity opens for tropical species to find a new home in latitudes that were previously inhospitable to them.
In addition to climatic causes, human activity plays a fundamental role in this dispersal process. Whether through the ballast water of large ships or by accidental transport on navigational equipment, these species find artificial dispersal routes which allows them to colonize new territories in record time. This combination of factors highlights the need for constant vigilance to prevent the balance of the seabed from being irreversibly disrupted.
Risk of co-invasion and competition for substrate
One of the points that most worries the IEO-CSIC team and their collaborators from the universities of Cádiz and Málaga is the phenomenon of co-invasion. Another highly aggressive exotic species, Rugulopteryx okamurae, has already been detected on the Galician coast, and the coexistence of both could be an explosive combination. If these two macroalgae manage to monopolize the seabed Simultaneously, native benthic organisms would be displaced, profoundly altering the entire food chain of the area.
The ability of these algae to cover large rocky areas and displace local species poses a direct threat to fishing and shellfish harvesting, vital sectors of the Galician economy. Therefore, the research emphasizes that the early detection and monitoring These are the best tools for anticipating ecological impacts. The GuardIAS project, funded by the European Horizon Europe program, works precisely along these lines to protect European waters from invasive alien species.
Surveillance and management plans in Galicia
The regional government is already taking action to control the spread of invasive plants. The Ministry of the Sea has activated various strategies, such as the Biomass Management Plan, to ensure that material removed from beaches and production areas does not return to the sea. Furthermore, significant funds are being allocated, such as the 1,9 million euros allocated to control of this type of species in coastal habitats, seeking to minimize the impact on shellfish harvesting areas.
In this fight, collaboration from citizens and the fishing sector is also fundamental. Platforms like Redogal allow fishermen themselves to raise the alarm when they find something unusual in their gear, feeding a public database essential for scientists. Thanks to initiatives like the The Algasdet project and the use of molecular markers Thanks to environmental DNA, it is now much easier to identify the presence of these algae even in the sediment, allowing action to be taken before the invasion becomes too obvious.
The recording of this first specimen of Asparagopsis taxiformis in 2025 constitutes a scientific milestone that compels us to rethink the vulnerability of our temperate ecosystems. Although it is still too early to know whether this macroalga will manage to form stable and permanent populations, its ability to disrupt the functioning of marine communities This is a reality already seen in other regions. Maintaining research efforts and constant monitoring will be crucial to protecting the biological richness of our estuaries in the face of the challenges posed by a constantly changing ocean.
