Fishermen fighting together to conserve livelihood

The Alaska fishing industry and the conservation community have aligned often on the same side of policy issues impacting our way of life and the resources on which we depend.

This happened during the fight banning high seas drift nets, which indiscriminately caught millions of Alaska salmon. The fight to prohibit fish farming in federal waters off the coast of Alaska and collaboration on the protection of water quality are other examples.

Issues involving global climate change and ocean acidification represent one more area where the fishing industry can join forces with the environmental movement.

Ocean acidification and global climate change are both result from excessive carbon dumping into the atmosphere. While climate change encompasses the varied impacts resulting from the greenhouse effect, ocean acidification is a straightforward chemical response to carbon dioxide emissions and is measured and predicted with a high degree of certainty.

Over the past 200 years, the oceans have absorbed 525 billion tons of carbon dioxide from the atmosphere, or nearly half of the fossil fuel carbon emissions during this period. This natural process of absorption has benefited humankind by significantly reducing the greenhouse gas levels in the atmosphere and thus minimizing some impacts of global warming. However, the ocean’s daily uptake of 22 million tons of carbon dioxide is starting to take its toll on the chemistry of seawater.

Carbon dioxide does not sit idly in the oceans. Recent field and laboratory studies reveal that the chemical changes in seawater resulting from the absorption of carbon dioxide are lowering seawater pH. The pH decline then decreases the availability of chemical building blocks needed by organisms that produce shells and skeletons made of calcium carbonate. Corals, as well as some free-floating plants and animals at the bottom of the food chain, have a more difficult time producing their shells, with potential consequences for other sea life that depends on these shelled organisms.

At present, the ocean’s chemistry is changing at least 100 times more rapidly than it has changed during the 650,000 years preceding our industrial era. And, if current carbon dioxide emission trends continue, computer models show that the ocean will continue to undergo acidification, to an extent and at rates that have not occurred for tens of millions of years.

Nearly all marine life forms the scientists have studied thus far that build calcium carbonate shells and skeletons have shown deterioration due to increasing carbon dioxide levels in sea water.

In experiments, when dissolved carbon dioxide was increased to two times pre-industrial levels (i.e., before the 1850s), the shell and skeleton-building rate of organisms studied declined by as much as 50 percent. Increasing ocean acidification has significantly reduced the ability of reef-building corals to produce their skeletons.

By the middle of this century, coral reefs may well erode faster than they can rebuild.
Lab results indicate that coral reefs cannot easily adapt to the changing seawater chemistry. While long term consequences are unknown, this could affect the geographic range of corals and the many life forms that depend on the reef habitat.

One type of free-swimming creature—the pteropod, a small snail with a calcium carbonate shell—is an important food source for North Pacific salmon. Pteropods provide over 45 percent of the food for juvenile pink salmon and are also eaten by mackerel, herring, and cod. Scientists believe that under conditions of increased ocean acidification the weakened pteropod shells will compromise the health of these organisms. This could mean substantial changes in the biodiversity of our oceans and, with the loss of this food source, profound economic changes for fishing families and coastal communities.

Aggressive action must be taken now to reduce carbon dioxide emissions. People involved in commercial fishing can seek ways to reduce the use of fossil fuels in harvesting, processing, preserving, and transporting fisheries resources.

The fishing dependent Alaska communities of Homer, Sitka, Haines, Petersburg, Kodiak and Juneau are engaged in efforts to reduce greenhouse gas emissions at the local government and community level. Our industry can use the same five basic steps: 1) Conduct a greenhouse gas emissions inventory. 2) Set emissions reduction targets. 3) Develop an action plan to reach the targets. 4) Implement the action plan and 5) Measure progress.

The magnitude of global climate change and the impacts of ocean acidification on shelled organisms could substantially alter the number, variety, and health of our ocean resources, with profound consequences. Funding for further research is needed along with specific local, state, and federal actions to reduce greenhouse gas emissions.

The time has arrived to stand in alliance with the conservation community and active local governments to demand strong action to protect our vital marine ecosystems. The threat is so great that we cannot afford to do otherwise.

Alan Parks has been commercial fishing in Alaska since 1975 and lives in Homer. When he’s not fishing, he works for Alaska Marine Conservation Council He can be reached at Parks will be in Cordova to give a lecture on this topic on Tuesday, Feb. 17.

Alan Parks, The Cordova Times, 12 February 2009. Article.

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