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In the early hours of March 24, 1989, a large tanker went aground on Bligh Reef in Alaska’s Prince William Sound, spilling 11 million gallons of oil into this thriving ecosystem. The historically important herring and roe fisheries were among many commercial species under threat in the sound. Pacific herring has been a critical subsistence fishery for Alaskan coastal communities, as well as being commercially harvested for food (including for their roe, a delicacy in Japan) and for bait for more than 100 years at the time of the spill. In addition to their commercial value, herring provide a key link between primary producers and larger animals in the food web. While a viable herring fishery still exists in some areas of Alaska, in Prince William Sound the population has never fully recovered in the aftermath of the Exxon Valdez oil spill. Recent data, however, hint at the possibility for change. The sound’s herring population is classified as an “injured resource” that is “not recovering.” Prior to the spill, herring populations were increasing in the sound, with record harvests (up to 121,000 metric tons) in the late 1980s. After the spill, the population became depressed, and collapsed to only 30,000 metric tons in 1993; since then it has fluctuated between 10,800 and 32,500 metric tons. Not surprisingly, the herring fishery in the sound has been closed for 15 of the 21 years since the spill. There are many theories about why the herring in this area have never recovered — from concern over growing whale populations, growing salmon populations and outbreaks of viral hemorrhagic septicemia causing hemorrhaging in fish. Equally complex is the question of how to best address the situation, with studies looking into the feasibility of a herring aquaculture program in Alaska. The idea is controversial, and Doug Hay, an expert in herring biology and ecology, says that “while technically possible, a program like that could fail on any number of biological levels.” What has been done is the funding of two main research projects, the Prince William Sound Herring Survey Program (2009-2013) and the Herring Research and Monitoring Program (2012-ongoing) conducted through the Prince William Sound Science Center. Ultimately, the two projects point to a problem with recruitment of juvenile herring. As Project Manager Scott Pegau points out, even small adult populations, like in Sitka Sound, can produce many offspring and large recruitment numbers, enough for a robust fishery in years to come. The fishery for herring this year in Sitka Sound alone targeted 16 thousand tons of herring with an average worth to fishermen of nearly $6 million. While Prince William Sound has adequate adult numbers to stimulate future populations, not enough of the larval and juvenile fish survive to adulthood to provide a high enough overall biomass for the fishery. “It all comes down to recruitment,” says Pegau, and lists factors like predation, food availability and currents causing larval drift as potentially limiting the juvenile herring population in the sound. The conclusion comes from years of data collected from the science center and employing a variety of techniques to study herring, including aerial surveys, acoustic surveys, trawl sampling and seasonal tracking of adult herring. Researchers now have a better understanding of not only the numbers of adult herring in the Sound, but also their health, fat supplies, and where they travel to feed and spawn. It’s because of this ongoing research that a glimmer of hope has surfaced about future herring populations: researchers at the science center saw a favorable year for recruitment in 2012 (often called a magical year), when many species seemed to flourish. It was a record year for young pink salmon and pollock, and the herring studied that year were also healthy, eating well and in large numbers. Problem is we won’t know just how successful a year 2012 was until those herring return to spawn in 2015. So there may be signs of better days to come. 2015 could be the year of new beginnings, as well as a potential turn-around for the devastated herring population in Prince William Sound, a truly magical year.

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