“Its ultimate objective is the development of methodologies that make it possible to guarantee or promote the sustained management of bivalves [and] of bivalve fishing,” said Miguel Gaspar of the Portuguese Institute of the Sea and Atmosphere (IPMA), who is the coordinator of the Venus project.
Gaspar told Lusa said that the project is divided into several actions, including the restocking of cockle species in the gulf of Cádiz.
“First, we have developed methodologies at our premises at the Experimental Molusciculture Station of Tavira, in the Algarve, methodologies for the production of bivalve larvae,” he explained, adding that a set of zootechnical technologies have been it is developed that make it possible to “obtain high-quality larvae”.
With a budget of €1,303,743.58, the project is co-financed by the European Union’s European Regional Development Fund (ERDF), under the Interreg V-A Spain-Portugal Programme (POCTEP) for the period 2014-2020.
After the process of producing larvae, IPMA, with the collaboration of the Portuguese Navy, houses a series of juvenile bivalves of up to 5 mm long, in marine areas.
“What we do, collaborating with several institutions - in this case the Portuguese Navy - is to spread a set of juveniles that we produce in our premises in areas where there was once a great abundance of these species,” Gaspar said.
According to the researcher, recently the IPMA repopulated an area near Portimão, also in the Algarve, with some 300,000 bivalves produced at the Tavira facility.
In promoting the sustainable management of natural bivalve banks, the Portuguese-Spanish project also had help from the University of the Algarve (UAlg),which is developing a set of protocols for the cryo-conservation of larvae, using ultra-cooled nitrogen.
“The cryo-preservation part comes in with this point of being able to design tools to preserve the germplasm of larva gametes [sexual cells],” Elsa Cabrita, a biology professor at the university, explained to Lusa. Later on they are revived to start fertilisation, which is undertaken in the laboratory.
“When I unpack a sample, in the case of spermatozoids, I must ensure that those sperm are viable and, like fresh semen, will be able to fertilise oocytes,” she said, referring to sexual cells produced in the ovaries.
However, Cabrita said that her team is for now not attempting the process with cockles, due to difficulties in their reproducing in captivity.
The project is due to finish on 31 December but Gaspar told Lusa that it is expected to be extended for a further year, “given the importance of the results” obtained in the last two years.
In addition to the IPMA and the University of the Algarve, the Spanish Institute of Oceanography and the University of Cádiz are partners in the project.