The Copenhagen climate summit has been much in the news for two weeks and the media is full of stories about rising carbon dioxide (C02) levels, increasing acidity of the oceans, drastic changes in weather patterns, the warmest decade on record, melting glaciers, rising sea water levels and coastal communities in imminent danger of inundation. And that’s just the tip of the melting iceberg! Excess nitrogen from fossil fuel-burning power plants, leachate from our septic systems and runoff from lawn fertilizers are wreaking havoc on our coastal ponds, over-stimulating algal production that in turn suffocates the life in marine ecosystems.
If the scientists are correct, the outlook for our crowded, fouled biosphere is far from rosy. Faced with such overwhelming doomsday scenarios, an anxious public considers its options. Sorry, turning up the air conditioning or speeding away in a Hummer to an unspoiled paradise far from the problem is no longer one of the options. The problems are of such a global nature that even Martha’s Vineyard is no longer a safe haven.
Audacious hope, however, springs eternal and “yes we can” must be our optimistic mantra. We pretty much created this mess, and we alone can solve it. Small changes in our lifestyles have bit by bit created these monumental problems, and small, but elemental, changes in our individual behaviors multiplied millions of times over can reverse them. The problems, too, are elemental. Carbon is at the heart of the climate/ocean acidity dilemma. Nitrogen is the focus of coastal ecosystem demise. The concepts of personal carbon and nitrogen “footprints” remind us of our individual roles in both the problems and the solutions. Now is the time for all good citizens to come to the aid of their planet and reduce their individual impacts.
There are a myriad of factors that influence the size of our pollution footprints and a multitude of actions we can take to lower our negative impacts. Believe it or not, shellfish (you knew this was coming!) offer one means to reduce our carbon and nitrogen footprints.
With respect to carbon, it is known that shellfish, as they grow, naturally absorb carbon from the oceans to create their shells of calcium carbonate. Very simply, this biosequestration, or uptake of carbon reduces the amount of C02 dissolved in the oceans allowing the oceans to absorb more CO2 from the atmosphere and, thus, lowers the levels of greenhouse gases implicated in global warming. Although the carbon removal by a shellfish bed may not quite compare with the carbon uptake occurring in rain forest vegetation, we can assuredly say that shellfish do sequester large amounts of carbon and their populations are beneficial to rectifying our climate dilemma.
When it comes to nitrogen pollution, the positive impacts of shellfish are even clearer. So much so that they are under serious consideration as a component in nitrogen pollution credit systems. There is good scientific evidence that the harvest of 10,000 oysters can mitigate the nitrogen pollution from one coastal household. As in the case of sequestering carbon, growing shellfish incorporate the nitrogen absorbed in the algae they consume into the protein in their tissues. When they are harvested, excess nitrogen is removed to the benefit of the entire local ecosystem. In addition, they remove nitrogen from the water column and deposit it in underlying sediments where denitrifying bacteria facilitate its removal as nitrogen gas.
Bottom line — the more shellfish on the planet the better our chances of bringing our world back into balance.
So, then, what can you personally do to increase the number of shellfish and lower your carbon and nitrogen footprints? One easy behavioral change is to eat shellfish more often. Consider changing your menu. Substitute a shellfish meal over beef or pork once or twice a week. You will be discouraging the production of inefficient, methane (another greenhouse gas) generating animals high on the food chain and encouraging the production of one of the most energy efficient sources of protein from planet-saving shellfish.
We at the Martha’s Vineyard Shellfish Group are committed to increasing the Island’s shellfish resources. In our solar-assisted shellfish hatchery in 2009, we produced over 10.5 million seed quahaugs, over 10 million seed scallops, over six million eyed oyster larvae and almost 400,000 seed oysters. Working with Island shellfish constables, these seed shellfish were planted in the Island’s ponds in an ongoing effort to restore our shellfish populations and perhaps in the process do our small part to save the planet. Please consider joining us in our efforts with your tax-deductible contribution to the Martha’s Vineyard Shellfish Group. You, too, can reduce your footprint one seed shellfish at a time.
Richard C. Karney is shellfish biologist and director of the Martha’s Vineyard Shellfish Group.