The sector detects a “sudden” and “unusual” increase in brittle stars that hinders fishing activity
The fishermen artisans who work in the area of the Cap de Creus (Alt Emporda)have denounced an “unusual increase” in captures of brittle starsa class of echinoderms related to the sea starsof the species ‘Astrospartus mediterraneus’, which is causing havoc in the fishing sector of the area. The large presence of these organisms damages nets and hampers fishing activitywhich is creating discomfort in the Catalan brotherhoods, has reported the Institute of Marine Sciences (ICM-CSIC), which acknowledges that until now, the information available on this species was very scarce.
“The information collected is important because it provides information about the biology of the species and recognizes the sudden increase of specimens and the problem it is causing for fishermen in the area, which has also been reported in other guilds on the Catalan coast”, explained the ICM biologist Marina Biel.
ICM biologists have published the details of the distribution and habitat preference of the species, emblematic of the Mediterranean, in a work published in the journal ‘Continental Shelf Research’. The authors highlight the importance of the new publication as it deals with an emblematic species of the Mediterranean.
Fishermen have reported “an unusual abundance” since 2018 of this star, which they accidentally catch more and more regularly, which interferes with their activity because the nets fill with these stars to the point of making work difficult.
Faced with this scenario, ICM biologists have monitored the species, with more than 140 outings to sea with fishermen, in which they have used underwater robots to determine the ecology and state of the species’ populations.
“Collaboration with the fishermen has allowed us to become aware of this phenomenon and investigate it. Without this exchange of information, the scientific community would probably have overlooked it,” highlighted the ICM marine biologist as well. Janire Salazar.
The results of the study show a preference of the species Astrospartus mediterraneus for rocky substrates with the presence of gorgonians -a type of coral- and a steep slope.
Possible mass outbreak
They also reveal that most are relatively young organisms, which fits with the fishermen’s perceptions and could indicate the beginning of a mass outbreak of the specieswhich would appear to be also expanding in other points of the Catalan coast such as the Gulf of León, where significant increases have been detected by the brotherhoods of Llançà, Roses and Palamós.
“If that were the case, it is possible that the population densities that have been observed will continue to increase and this could become a chronic situation, which is why exhaustive monitoring of the population is necessary so as not to endanger the fishing activity,” he said. pointed Andreu Santinanother of the authors of the study.
In fact, following its publication, several guilds on the Catalan coast have expressed their willingness to monitor the evolution of the species given the interference it causes them in their activity, because fishermen spend many hours removing brittle stars from the networks.