By Brendan Smith

Thanks to greenhouse gas emissions, it’s looking like my days as a commercial fisherman are numbered.

I’ve been working the sea on-and-off my whole life. At 15 years old I quit high school to work the lobster boats out of Lynn, MA; later I fished cod and crab boats on the Bering Sea. As over-fishing decimated the cod stocks, I headed back home to Newfoundland to try my hand as a fish farmer growing halibut and salmon.

Now I’m an oyster man, growing 100,000 organic oysters a year on a 40 acre plot in the Long Island Sound. I see myself as a new breed of green fisherman, who have shifted from hunter-gatherers trolling the seas in search of declining fish stocks, to ocean-based farmers, sustainably growing shellfish on small plots of ocean acreage for local markets. (Oysters rank as one of the top “super green seafoods” by the Environmental Defense Fund.)

But now, just as I’ve regained my green sea legs, scientists tell me that in the coming decades I won’t be able to make a living growing oysters anymore. They tell me greenhouse gas emissions from burning fossil fuels are turning the oceans acidic, and oysters, already fickle little creatures, are likely to be the first victims.

Here’s how the marine biologists tell me the process works: Oceans absorb about 25 percent of the world’s greenhouse gases from human activities. The problem is that too much CO2 absorption also raises water’s acidity. Increased acidity reduces carbonate — the mineral used to form the shells and skeletons of many shellfish and corals. The effect is akin to osteoporosis, slowing growth and making shells weaker. If pH levels drop enough, the shells will literally dissolve.

The acidification of the ocean today is larger and faster than anything scientists can find in the fossil record over the past 65 million years. According to a recent study in the journal Natural Geoscience, current ocean acidification is taking place at ten times the rate that preceded the mass marine extinction 55 million years ago.

Oysters and other shellfish are expected to be some of the first victims of ocean acidification. Researchers at Stony Brook University’s School of Marine and Atmospheric Sciences found that even minor increases in ocean acidity have significant, detrimental effects on the growth, development and survival of hard clams, bay scallops and oysters. Scientists already suspect that acidic water is responsible for killing several billion oyster, clam and mussel larvae that were being raised at the Whiskey Creek Shellfish Hatchery on the Oregon coast in the summer of 2008.

But it’s not just my oysters and livelihood that are imperiled. Shellfish and other vulnerable species function as crucial links for entire ecosystems in the ocean. According to the NRDC:

The new chemical composition of our oceans is expected to harm a wide range of ocean life. The resulting disruption to the ocean ecosystem could have a widespread ripple effect and further deplete already struggling fisheries worldwide… A more acidic ocean could wipe out species, disrupt the food web and impact fishing, tourism and any other human endeavor that relies on the sea.

Commercial fishermen have conflicted hearts. We’re famously independent, often wary of government regulation. We have traditionally had a complex, often combative relationship with the environmental movement. But at the same time, we also have a deep respect and love for the sea. Our lives, our livelihoods, are held at the mercy of natural forces more than almost any other occupation.

Politicians try to cast workers as not caring about protecting ocean resources and the perilous effects of greenhouse gases. They say the coming crisis is too far off and we’re more fearful about environmental policy destroying jobs. Exactly the opposite. Protecting my life and livelihood requires protecting the oceans and planet.