Cashes Ledge Lobster

An Ocean Warming: Ocean Acidification, Lobster, and the Need for More Research

Year after year, temperatures in the Gulf of Maine’s waters have risen at unprecedented rates, a result of the same increased concentrations of atmospheric greenhouse gases (primarily carbon dioxide derived from human activity) responsible for climate change.

This has caused a slew of problems for the marine life in the area – and it also means serious trouble for the ocean’s biogeochemical composition. The ocean has always served as Earth’s largest “carbon sink,” meaning that naturally occurring and industrially produced carbon dioxide is dissolved into seawater and, through a chemical synthesis process, forms carbonic acid.

Carbonic acid breaks down into ions that increase the ocean’s acidity. Over time, marine species have evolved alongside this process in a steady transformation leading to a balanced pH for the ocean.

But, as humans have deepened their addiction to climate-warming fossil fuels, more and more carbon dioxide is being pumped into the atmosphere – meaning the ocean is taking on more carbon dioxide than ever before. These drastic increases change the ocean’s pH level, throwing it off balance and making it more acidic.

Learning as we go

The full effects of ocean acidification are not yet entirely known, but we have begun to see its effects on certain species. The group of species most threatened by ocean acidification are some of the most important to New England’s coastal economy: the ‘calcifiers’ – lobsters, scallops, oysters and other fish that use the carbonate and calcium ions dissolved in seawater to build their shells.

As the water becomes more and more acidic, it becomes harder to for these species to make and maintain their shells. And as they devote more energy to constructing their shells, less energy can be given to other essential processes, like eating or reproduction.

An uptick in shell disease threatens the fishery

For the American Lobster, ocean acidification has been shown to have devastating effects on the growth and shell building rates of juveniles, making them significantly more susceptible to threats like predation and disease.

A shell disease that creates unsightly lesions in the lobster’s hard exoskeleton, for example, had previously been thwarted by colder water temperatures. But that disease has now slowly begun to creep its way up the coast and into the Gulf of Maine. Given the increasing vulnerability of lobsters, and juveniles in particular, this shell disease and other threats have the potential to inflict serious harm on the species, the fishery, and New England’s economy as a whole.

A Lesson in Taking Initiative

The threats facing our oceans due to ocean acidification have prompted several states to take the initiative to begin to address the regional impacts of coastal and ocean acidification. This spring, Massachusetts senators and representatives are working on a bill that will create a special commission to examine the existing and potential effects of ocean acidification on both ecologically and economically important species in the waters off of Massachusetts.

This bill, Resolve H. 716, follows a rough framework laid out by states like Washington and Maine who have already approved commissions to confront the threats of ocean acidification.

In a recent roundtable forum, Massachusetts Congressman Bill Keating emphasized that thorough research on ocean acidification is critical because without the best scientific knowledge, it is impossible to know how Massachusetts should take action.

Following in Washington’s footsteps is an excellent starting point for this work, however the situation facing Massachusetts and Maine (and New England at large) is unique. In the Gulf of Maine, scientists are witnessing changes in temperature and pH more rapidly and dramatically than almost anywhere else in the world – and its waters face a unique stressor due to the arctic ice melt and the resulting influx of freshwater. On top of the environmental factors, New England is especially vulnerable due to its economic dependence on susceptible species such as lobster.

Next Steps

There’s no question that establishing a devoted task force to study ocean acidification and what it means for the people and species in Massachusetts and New England will be helpful. With the support of strong science and the engaged voices of all stakeholders, addressing New England’s unique ocean acidification challenges is an important step in addressing climate change in our region.