The Downeast Salmon Federation is raising money to install a filter system and ultraviolet sterilization process in its East Machias Peter Gray Hatchery after a viral infection made it necessary to kill all of its 170,000 fish.
Although they looked healthy, the parr, which is a juvenile stage of the fish, tested positive for infectious pancreatic virus last week during a routine hatchery disease screening, according to a federation newsletter.
The virus naturally occurs in Maine waters and would have come from other fish species or birds, Dwayne Shaw, executive director of Downeast Salmon, said on Wednesday.
Downeast Salmon has been working for more than 30 years to help restore Maine’s wild salmon population in Washington County rivers. This is the first time in the organization’s history it has had to kill an entire crop of fish because of disease.
“This single year setback is not going to hold back our intentions to recover Atlantic salmon,” Shaw said in a federation newsletter.
Atlantic salmon seem to be mostly immune to the virus in the wild, but the Infectious Pancreatic Virus is considered highly contagious, he said. The federation plans to find a safe burial place for the dead fish.
The fish originally came from Craig’s Brook Fish Hatchery in Orland as “eyed eggs” — when the eye of the fish is visible through the shell — in February. The East Machias facility hatched the eggs and raised the fish to the parr stage.
Each river has its own strain of Atlantic salmon, which are raised and released into the appropriate river, Shaw said. The rivers are East Machias and Narraguagus for the East Machias hatchery, and Pleasant for the Pleasant River hatchery.
Fish are tested before they are released in the wild. Maine Department of Marine Resources, which controls the hatchery’s permits to stock fish in the rivers, would not have allowed the infected parr into the wild ecosystem, Shaw said.
The facilities’ systems, developed by Peter Gray in England and Scotland, draws unfiltered water from the rivers into the hatchery, which is how the virus likely was introduced to the parr, he said.
The idea of the Gray system is to raise the fish in the water and conditions where they eventually will live, letting natural selection occur in the hatchery rather than in the wild. It reduces mortality when the parr are released to their respective rivers, he said.
The federation has two matching grants — one is a U.S. Fish and Wildlife Recovery Challenge Grant and the other from an anonymous donor — lined up to pay for the new equipment, but needs to raise at least $75,000 to activate them.
The modifications to the hatchery will include filtration that removes sediments and fine solids, and a high-level ultraviolet light system that will kill Infectious Pancreatic Virus. All other aspects of the Gray system will remain in place.
The entire process, from raising money to testing the new system, must be completed by the end of February when the hatchery will receive its latest batch of East Machias and Narraguagus strains of eyed eggs.
On top of the issue at the Peter Gray hatchery, the federation is raising $1 million to expand the Pleasant River hatchery based on the success rate of the fish released into the rivers from the East Machias facility. The group has already received $275,000 as an anonymous family gift toward the project.
Both facilities are former hydroelectric plants where the dams were removed, the flow of the rivers restored and the buildings renovated into hatcheries.
Shaw said he didn’t know why the fish suddenly tested positive for the virus. He said the large amount of rain this year that caused high water flows in the rivers and the cool temperatures were the only environmental differences from other years.
