But salmon are an anadromous fish which migrate to sea, and the forces at play in the marine environment are much more of a mystery, he said, when it comes to understanding impacts on salmon in the ocean. Salmon was listed as endangered under the Endangered Species Act (ESA) in December 2000. At the time, NMFS and USFWS said the number of wild salmon in Maine rivers is “at an all-time low, placing them in danger of extinction.” The listing required the implementation of a recovery plan, which the two services began drafting in 2001. The final plan incorporates numerous changes made in response to comments received on the draft plan, published in 2004, from the public and from peer reviewers. As anadromous fish, salmon typically spend 2-3 years in freshwater, migrating to the ocean where it also spends 2-3 years, and returning to its natal river to spawn. The Gulf of Maine’s “distinct population segment” (DPS) includes all naturally reproducing remnant populations of salmon in at least eight rivers known to still support wild Atlantic salmon populations — Dennys, East Machias, Machias, Pleasant, Narraguagus, Ducktrap and Sheepscot rivers, and Cove Brook. There are also at least 14 small coastal rivers within the historic range. DPS salmon taken for hatchery rearing for broodstock, along with their progeny, are included as part of the population, but they do not count toward delisting or reclassification. The salmon population has declined to critically low levels, and adult returns, juvenile abundance estimates and survival continue to decline since the listing. In 2004, total adult returns to all eight rivers were estimated to range from 60 to 113 individuals. No adults were documented in three of the eight rivers. Declining smolt production has also been documented in recent years, despite fry stocking. For example, from 1996-99, annual smolt production in the Narraguagus averaged about 3,000 fish. Smolt production declined significantly in 2000 and for the past three years averaged only about 1,500 fish per year. Not terribly long ago, Keliher said, the Penobscot River alone had up to 10,000 adult salmon that returned every year. Rivers that once had up to a thousand fish returning annually now see only a few. The salmon’s endangered status occurred for a number of reasons, including critically low adult returns, impact on the quality of freshwater habitat, continuation of the commercial fishery in Greenland, the threat of disease from infectious salmon anemia, increased likelihood of predation because of low numbers of returning adults and increases in some predators, and aquaculture practices at the time, which included the use of European salmon and posed genetic risks. The plan identifies 13 of the biggest threats to naturally reproducing salmon populations in Maine and nine primary recovery actions designed to stop and reverse downward population trends, beginning with better protection and restoration of freshwater and estuarine habitat. The discussion of threats was significantly expanded in comparison to the draft plan, with more information on current habitat conditions, elevated water temperature, and pesticides. “The new plan gives recovery efforts a focus,” Keliher noted. As part of the planning process, the services assembled a team that includes experts drawn from government, academia, and the private sector to analyze which threats should receive highest priority for action to reverse the decline of salmon. Threats receiving highest priority include acidified water and associated aluminum toxicity, which decrease juvenile survival; aquaculture practices; avian predation, changing land use patterns such as development, agriculture and forestry; climate change; incidental capture of adults and parr by recreational fishermen; introduced fish species that compete or prey on salmon; low ocean survival, poaching of adults; and sedimentation. Some measures are already in place, Keliher said, including a ban on European salmon in Maine’s aquaculture operations. Significantly, the plan avoids making a prediction as to when recovery might be achieved and criteria have not been established for determining when the DPS can be reclassified or delisted. “The species continues to decline and its status is precarious,” the report says. “Even when we achieve a complete reversal of downward trends and population growth, it is not possible to estimate the date of recovery of the DPS.” One of the biggest challenges in recovery, said Keliher, is the people factor —younger generations simply do not remember what the rivers looked like when they teemed with salmon. That gives an important role, he said, to educational programs such as those offered by Trout Unlimited, which places tanks and smolt in classrooms and helps students release the fish into rivers when they reach the fry stage. “All fishing had to stop, so people don’t have a connection to the fish anymore,” he said. “People don’t see them migrating over the waterfalls.” Keliher is optimistic about the plan’s potential benefits for helping salmon in their freshwater habitat. But the problem is much broader, he said, with much of the decline occurring in federal and international waters. “Ocean mortality is much more of a mystery,” he said. To tackle that side of the problem, MASC works closely with NMFS and with the North Atlantic Salmon Conservation Organization (NASCO) to resolve marine threats as well, with an eye toward identifying threats and developing precautionary management measures. NASCO is an international organization established under the Convention for the Conservation of Salmon in the North Atlantic Ocean, established in 1983. The objective of the organization is to contribute through cooperation to the conservation, restoration, and management of salmon stocks, which migrate beyond areas of fisheries jurisdiction in the North Atlantic. NASCO members are the U.S., Canada, Denmark, representing the Faroe Islands and Greenland, where there are active commercial salmon fisheries, Europe, Iceland, Norway, and Russia. “For the entire state of Maine, I’d say we stopped the decline, but at very low numbers,” Keliher said. “We’re in a critical stage: we have to keep the life support system going.” The Final Recovery Plan may be obtained from NMFS, One Blackburn Dr., Gloucester, Mass. 01930; (978) 281-9328; www.nmfs.noaa.gov. |
