| Pacific Herring (yaaw) are a popular baitfish in the region and also used for consumption. Herring eggs (gáax’w) are particularly prized as they are one of the first fresh foods of spring and mark the end of a long, dark winter. The importance of herring and their eggs to the Tlingit people make them a cultural keystone species, and the eggs are commonly savored and preserved for cultural events later in the year. Herring are also an important bait fish, widely used by local subsistence users for catching halibut and crab, and are a vital food source for many marine mammals and ground fish. One tribal member spoke at length about the value of herring in the ecosystem and how further losses in their population would lead to trophic cascade, wiping out species higher on the food chain. |
Primary Risks
RISING WATER TEMPERATURES AND OCEAN ACIDIFICATION THREATEN HERRING EGGS.
Data collected over two decades showed that rising water temperature led to earlier spawning and faster growth of young herring. In addition, a separate study found that herring roe exposed to higher water temperatures tended to be shorter, with larger yolks. Those exposed to ocean acidification were longer with smaller yolks. While these two exposures seem to cancel each other out to the naked eye, it was apparent at the molecular level that eggs exposed to warmer temperatures and acidification were compromised. They were stressed and their protein expressions were not functioning normally. This change may go unnoticed by those managing herring stocks, who regularly do so by keeping track of average weight and ages in the population, but don’t take into account RNA:DNA ratios.
THEIR PRIMARY FOOD SOURCES (PHYTO-AND ZOOPLANKTON) ARE HEAVILY INFLUENCED BY CLIMATE CHANGE.
While warmer oceans could increase the production of phytoplankton and provide forage fish with more nutritional resources, warmer waters also hold less oxygen and require more energy to be spent on growth and reproduction. Ocean acidification also has negative impacts on zooplankton and small pteropods that are important foods for herring. It is currently unknown how the relationship between increased energy needs and increased food availability will change in the future.
REGIONAL HERRING STOCKS HAVE BEEN HEAVILY DEPLETED BY OVERFISHING.
The current herring population represents only a small fraction of their historical abundance, mostly due to overfishing.
The smaller population of fish are more susceptible to being negatively impacted by a changing climate. Several tribal members reported that when they were younger the herring were much more abundant near town, and that they were concerned by drops in the population. Herring eggs are currently harvested in Sitka and brought to Hoonah for local consumption, leaving local stocks to recover with less interference. One resident linked the building of the new creosote-covered harbor to the drop in herring populations, implying that human development may continue to have negative effects on fish.
IMPACTS TO HERRING IMPACT THE ENTIRE ECOSYSTEM.
Herring is an important part of the marine ecosystem and a commercially important fish species. Herring are a vital food source for sea lions, whales, marine birds and larger fish. They are also used as crab and fish bait by local subsistence users.
Adaptation Strategies
SHORT-TERM GOALS:
1.1: Add Pacific Herring to Alaska’s Forage Fish Management Plan
1.2: Encourage the growth of marine plants and seaweeds to improve herring habitats
1.3: Continue work on restoring the Icy Straits Advisory Committee to advance local voices on herring management
MID-TERM GOALS:
2.1: Recruit local herring experts to be a part of the field research teams studying herring
2.2: Consider feasibility of herring egg transplantations to enhance spawning stocks
2.3: Work with the city and State to prohibit disturbances of key spawning areas.
2.4: Institute sanctions on irresponsible herring harvesters
LONG-TERM GOALS:
3.1: Manage herring populations with a cultural-historical perspective – look at numbers from across the past 3 or more generations, rather than the past 40 years. 3.1.1: Use Local and Traditional Tlingit knowledge to inform research and future decisions about herring