Nacra is a large bivalve. Giant mussels special to the Mediterranean, and is the second largest in the world, with some specimens reaching a length of one meter over a 15-year lifespan. one plays It plays a crucial role in filtering the water as well as providing a home for a wide variety of creatures. underwater. This applies to sponges, sea anemones, algae and other species that live in their shells.
But it was nacra parasite victim haplosporidium pinnaKilling 99.9% of the population since 2016reducing their numbers from millions to a few thousand. This major death event led to the mollusc being included in the International Union for Conservation of Nature’s (IUCN) red list as critically endangered in 2019.
“The situation is critical. We need large-scale coordination because We are witnessing the extinction of a very important species.He told the British newspaper Guardian Patricia Prado (who devoted a comprehensive report to this case), researcher at the Sant Carles de la Ràpita Institute of Technology and Agrifood in the Ebro Delta, is one of eight research centers in the Mediterranean that are part of the Pinnarca project. , an EU Life program to save mollusks from extinction.
interference H. pinnae unusually deadly. Prado thinks this may be because it works with bacteria that mussels may already have. He notes that the origin of the parasite is unknown, but he suspects it. Global warming is related to human activities such as shipping or agriculture. The spores of the parasite live not only in shells, but in water.
It’s not just a parasite
However, protozoa are not the only cause of mussel decline. In the Mar Menor, a salty lagoon in southeast Spain, the population has dropped from 1.7 million to 1,000. excess nitrogen in water caused by fertilizers used in agriculture. The process known as eutrophication deprives marine life of oxygen, and shellfish are among the victims.
Young specimens also in the Ebro delta blue crab, an invasive species Believed to have come by ship from the United States, its voracious appetite nearly wiped out the native crab species.
The largest nacra population in the delta is found in the shallow, protected waters of Alfacs Bay, with up to 90,000 surviving. The parasite appears to need an optimal salinity level to thrive, and Prado and his team hope that relocating individuals to areas of the delta with lower salt levels could help mussels thrive. Guardian.
“We try to preserve the surviving population and exchange individuals between groups to avoid inbreeding, otherwise they will die due to a lack of genetic diversity,” he says.
They also try to raise healthy individuals.. Since mussel farming is an important industry in the delta, there is a lot of experience in this field, but no luck so far. Mussels are slow to reproduce and do not do this every year. In addition, Prado says, “it has a population-regulating mechanism, which makes it difficult for us to breed them if they’re programmed not to breed at certain times.”
Reasons for hope?
However, a marine ecologist at the AZTI institute affiliated with the Basque Research and Technology Alliance, Dr. Ángel Borja believes there are reasons to be optimistic. “Science has an important role in identifying problems and communicating them to the community, but especially in developing affordable solutions,” he says. “Despite the threats to the ocean, we have seen many examples of positive results in recent years. in conservation, so there is reason to speak of ‘ocean optimism’.
Mike Elliott, Professor of Marine Sciences at the University of Hull, adds: “All countries, and especially those in the EU, have plans and projects in place to halt biodiversity decline and restore habitats, species numbers and size as Pina.
“Recreating a habitat is not only good for biodiversity, it can also protect people against the effects of climate change, such as rising sea levels. In most cases, Recreating a habitat will allow a species to recover as long as there are nearby populations to repopulate it.
But Elliott adds: “The slow-growing, long-lived species have irregular populations. pinnaThey will need more protection, and habitats once lost may be more difficult to restore.”
Prado insists it is vital to try to save nacra because of its vital role in the ecosystem. “It is a habitat in itself, so losing nacra means losing biodiversity.Prado says. “We need to intervene because there is no point in waiting for things to get better on their own, especially since we are the cause of so many problems.
“People argue that it’s part of a process, that some animals will go extinct and others will replace them, but as a species we depend on what already exists,” he concludes.
Reference article: https://www.theguardian.com/environment/2022/jun/17/mollusc-mass-mortality-event-can-spain-giant-fan-mussels-recover-aoe
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