March 3, 2014
Contact: Shelley Dawicki
Researchers Discuss Habitat and Life History Diversity of Atlantic Salmon and other Diadromous Fishes at Maine Forum
More than 165 participants from the Northeast and Northwest U.S. and Atlantic Canada gathered in Orono, Maine, January 8-9 to attend the 7th biennial Atlantic Salmon Ecosystems Forum.
Attendees from as far as Washington and Idaho heard and viewed more than 50 oral and poster presentations given on the science, management, and restoration of diadromous fish species and their habitats in New England, Atlantic Canada and the Northwest Atlantic Ocean.
Mark Renkawitz of the Northeast Fisheries Science Center (NEFSC) and Tara Trinko Lake from the Greater Atlantic Regional Fisheries Office (GARFO), served as co-convenors of the forum, which has broadened its original focus on salmon to include other diadromous species.
“Atlantic salmon constitute a small portion of the overall fish biomass in the Gulf of Maine but are part of a much larger diadromous species community,” Renkawitz said. “Despite the name, the forum is not completely salmon-centric and encompasses sturgeon, river herring and other sea-run species and their habitats, and the role each plays in the ecosystem.”
The meeting focused on estuary and marine ecology, diadromous species ecology, freshwater ecology, and applying science to management. Topics ranged from migration, predation, and habitat to the impact of dam removals and improved fish passage. The forum was co-sponsored by NOAA, the Diadromous Species Restoration Research Network (DSRRN), Project SHARE (Salmon Habitat and River Enhancement), the Atlantic Salmon Federation (ASF), The Nature Conservancy (TNC) and the U.S. Fish and Wildlife Service.
“Improving and maintaining habitat diversity and life history diversity of the various species in the ecosystem is critical,” Trinko Lake said. “In the last 10-15 years, there has been a lot of attention paid to the relationship between salmon distribution, abundance and oceanic conditions including climate change, and the timing of migrations. This meeting brings researchers from different fields and managers together to exchange the latest information.”
Maine’s Penobscot River has the largest Atlantic salmon run remaining in the United States. Although salmon numbers remain very low in New England, access to habitat has improved as dams have been removed and fish passage improved. The Penobscot River Restoration Project, a collaborative effort to restore 11 species of sea-run fish to the river while maintaining energy production, has led to the removal of the lowermost dams on the river. The removal of Great Works Dam in 2012 and Veazie Dam in 2013 opened the section of river between Veazie and Milford to sea-run fish for the first time in almost 200 years. Future fish passage upgrades are also scheduled for the river’s Howland Dam in 2014.
More than 3,000 Atlantic salmon returned to the Penobscot River in 2011, the highest number since the mid-1980s. Although fewer salmon returned in recent years, researchers like NEFSC’s John Kocik are cautiously optimistic the Penobscot River population can rebound. “The expected positive effects of improved fish passage are an essential step in increasing the number of salmon that head to sea,” Kocik said. “The research presented at the forum is helping us understand the next steps of improving marine survival.”
Kocik, head of the Northeast Salmon Team, has been working with the Atlantic Salmon Federation and with Canada’s Department of Fisheries and Oceans since 1997. U.S. and Canadian salmon have experienced record low survival at sea since 1990. Trying to figure out why the survival rates are so low, and where the losses are happening, has been a priority.
“We can’t study salmon or save them if we don’t know where they are,” said Kocik, who gave a presentation on migration timing of Atlantic salmon smolts from Penobscot Bay to the Scotian Shelf at the forum. “Studying salmon at sea using telemetry enables us to tag and follow very small fish in saltwater. We have also used satellite tags to study adult salmon at West Greenland to look at their return trip. Tracking wild Atlantic salmon with tags has provided information on the migration cycle and where mortalities occur.”
Other technologies, such as hydroacoustic monitoring, have enabled researchers to better understand where salmon smolts and other river-run species are found at different times of the year and in what locations in the Penobscot River. A comprehensive fisheries survey of the Penobscot Estuary to monitor and describe pre-and post-dam removal conditions was conducted by NOAA Fisheries from 2010 to 2012 using mid-water trawling, seining, fyke nets and hydroacoustics. Some results from that study and ongoing research were presented at the recent forum.
“We’re focused on the ecosystem as a whole,” Renkawitz said. “Our ongoing research projects focus on the estuary, on the near shore marine ecosystem, and on the large-scale ocean ecosystem and what role oceanographic conditions may play in the survival of salmon and other diadromous fish species. We want to determine what makes a healthy estuary, a healthy ecosystem, and if it is broken, how do we fix it for future generations.”
Monitoring diadromous species in Maine rivers begins again in April, when salmon smolts head to sea. NEFSC staff will be on the river tracking fish and their movements.
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