DAGUPAN CITY, Philippines – The blue mussels along the Brazilian and Colombian coasts of South America traversing the Panama Canal have reached coastal waters here by way of the tropical Eastern Pacific.
Dr. Michael Rice, a professor of the Department of Fisheries, Animal and Veterinary Sciences at the University of Rhode Island told The STAR in an e-mail recently that the blue mussels found in Pangasinan were identical to the shellfish in the Eastern Pacific.
“They are Mytella charruana, the Charru mussel that are identical to a strain found from Mazatlan, Mexico to Ecuador in the Eastern Pacific,” he said.
Rice issued this statement after results of the DNA test – done by Paul Rawson of the University of Maine – were released based on samples of blue mussels taken from Dagupan river.
Rice, a frequent visitor to the Philippines, said the formal presentation of data is scheduled on Jan. 12, 2016 at the US National Marine Fisheries Service Shellfish meetings in Shelton, Connecticut.
He said the DNA result “is so precise that it not only identifies exactly what species the mussel is, but the location of the sub-population of the mussel.”
He said tracing the DNA of the Pangasinan mussels is exciting “because we can study how a new species adapts and changes once introduced into a new environment very far from its origins.”
DNA is a self-replicating material present in nearly all living organisms as the main constituent of chromosomes and the carrier of genetic information.
In the copy of the abstract of the DNA result, it partly said that these mussels with a thick black periostracum were first reported in the Calmay River near the village of Tucok, Dagupan City. Samples of mussels were preserved in 95 percent ethanol and sent to Maine for genetic evaluation using amplified mtDNA sequences coding.
“Using Basic Local Alignment Search Tool (BLAST), there is a 100 percent identity match over ~600 bases to Haplotype B of Mytella charruana, the Charru mussel, with a native range on the Pacific coast of the Americas from Guaymas, Mexico to Ecuador, and introduced to the Atlantic coast of Florida in 2009,” the study said.
It noted that the mussels are spreading rapidly in Pangasinan.
In July 2015 freshly set mussels were found in Western Tambac Bay. In September, mussels were found in the Limahong Channel near Lingayen, an estuary contiguous with the original Tucok site.
“All sites with Charru have considerable seasonal salinity fluctuations and stratification during the dry season, but are primarily within the polyhaline salinity regime. Charru mussels are now fished and sold… suggesting good potential for aquaculture,” the report added.
Dr. Westly Rosario, center chief of the Bureau of Fisheries and Aquatic Resources-National Integrated Fisheries Technology and Development Center here, said, “We were the first in Southeast Asia to report blue mussels presence.”
“What is positive here is these blue mussels grow even in very low salinity areas where red tide toxins could not bloom,” Rosario told The STAR.
“Good for climate change problems,” he said, adding the mussels are more resilient in salinity and temperature.
Rosario said the meat of the blue mussel is excellent compared to green-lipped tahong.
The introduction of the blue mussel in the Philippines is possibly due to shipping activities. “Accidental introduction. Just like how red tide was introduced in many countries,” he said.