The animals were released in one of the two sanctuary areas recently created in the estuary, between Faro and Olhão, where artificial reefs were placed that recreate their natural habitat, so that they can settle there.
As part of a repopulation project, a group of 60 seahorses, most of them born in captivity, was released this week in the Ria Formosa, where 20 years ago the largest seahorse community in the world was concentrated.
In 2000, the community of these fish in the Ria Formosa, Algarve, was considered the largest in the world, but in 20 years "there has been a reduction of 96% in numbers", Jorge Palma, researcher at the Centre for Marine Sciences told reporters (CCMAR) of the University of the Algarve (UAlg).
The animals were released in one of the two sanctuary areas recently created in the estuary, between Faro and Olhão.
Most of these seahorses were born in the tanks of the Ramalhete Marine Station, in Faro, but their parents are specimens that lived in the wild and were taken there in order to breed, thus contributing to conservation of the species.
The initiative, carried out under the 'Seaghorse' project, "makes sense because the introduction is made in a protected area, otherwise they would be exposed to negative effects that may still exist in the estuary", stressed Jorge Palma, noting that the objective is that the animals are concentrated in the sanctuary.
The seahorses were transported by boat in two tanks to a protected area, about half a mile off the coast, where sailing is prohibited and were then carefully placed in small cages to be taken into the water by divers.
The team of divers took the cages to the bottom, at a depth of about four metres, to then release the animals next to the artificial reefs that will become their habitat.
According to Jorge Palma, these fish are “completely different from all the others” and also “poor swimmers”, which makes them “very vulnerable”, as they “have to be always attached to something”.
"Although all of the seahorses released on this occasion are only between seven months and a year old, they are already adults and during their short life in captivity the ability to survive in the wild has been preserved," explained Jorge Palma.
“What we gave them in captivity is not feed, they have natural prey that they have to hunt in tanks, so when they are released, they will maintain this ability to survive in the natural environment”, noted the researcher.
In a month, the team will return to the site to monitor the evolution of the new population, a task made easier by the fact that these fish have, depending on the species, physical characteristics that distinguish them from each other, also allowing them to differentiate them from those that were already in the wild. .
“Before releasing them, we took pictures of each one and they have a natural marking that allows us to distinguish them”, observed Jorge Palma, explaining that the “hippocampus hippocampus” (a species with a short snout) have a marking on the top of the head and the “hippocampus guttulatus” (a species with a long snout) a pattern of spots on the body.
The population of seahorses in the Ria Formosa has suffered a drastic reduction in recent decades, having almost disappeared due to factors such as environmental changes, the destruction of seagrass meadows, their habitat, illegal fishing, or excessive boat traffic.
The initiative to repopulate seahorses in the Ria Formosa was carried out by CCMAR under the 'Seaghorse' project, with funding from the Belmiro de Azevedo Foundation.
The project will also investigate the dynamics of seahorse populations and try to understand the role of seagrasses as supportive habitats and food providers.
Another of its objectives is to find out if this role of seagrasses could be affected by the recent invasion of the Ria Formosa by the alga “Caulerpa prolifera”.
The project also involves the maritime authorities, the Institute for Nature Conservation and Forests (ICNF), the Ria Formosa Natural Park and the Portuguese Environment Agency (APA).
Original article available in Portuguese at http://postal.pt/
