Photo Credit: Natacha Hardy.
Alex Koeberle and Scituate Fisherman Frank Mirarchi
By: Alex Koeberle and Jake Kritzer
Following the hottest summer ever on record, the Atlantic coast was rocked recently by super storm Sandy, both stark reminders that climate change is increasing the frequency and severity of extreme weather events. This year had already seen effects of climate change take on a more prominent place in marine conservation debates. In July, renowned Australian ecologist Dr. Roger Bradbury argued that the fate of coral reefs is essentially sealed due to warming waters, rising seas, acidification and extreme weather (although other prominent voices were quick to counter such doomsday predictions). Closer to home, an effort to restore Atlantic salmon to the Connecticut River was ended after nearly a half-century, in part because changing ocean currents, temperature regimes and plankton production might be impairing the ability of salmon to survive at sea and migrate back to spawn.
It is not only salmon that are contending with effects of climate change in New England. The region is seeing sea levels rising faster than many other places around the globe, which threatens to drown salt marshes already struggling with excessive nutrient loads. Marshes help buffer coastal areas against storm surge, and provide vital nursery and feeding grounds for many important fish species. Ocean waters are not only rising but warming as well, one consequence of which has been a dramatic shift in the distribution of cod north of the primary fishing grounds in the western Gulf of Maine. Also, rainfall patterns are becoming increasingly erratic, altering salinity profiles and plankton production, which hampers productivity of species throughout the food web. Read More
Photo from NOAA
New England has received a lot of media attention recently about the fisheries disaster declared by President Barack Obama. The precipitous decline in groundfish in New England waters has created an imminent need to help fishermen and fishing communities that depend on stable healthy fish populations.
It is important to dispense with false rumors and to set the record straight. There is an effort on the part of some to claim that catch shares are somehow responsible for the New England groundfish population declines. To claim this is to suggest that fishermen have exceeded their catch limits and are not following the rules. This is simply not true. In fact, sector fishermen have been working hard to stay under their catch limits, and in some cases remain well below these limits.
In reality, the disaster declaration was based on the fact that there are changes happening in the ecosystem that are impeding the rebuilding of fish populations. We are forced to confront the frightening reality that fishing is changing in part because our oceans are changing. We are dealing with a resource problem, not a management problem. Read More
The recent U.N. Climate Change conference in Copenhagen highlighted the range of challenges associated with fighting climate change, from cutting energy use to financing clean technology in developing countries. Why the global sense of urgency and focus? Because the impacts of climate change are already being felt. Most of our discussions center on the dangers of sea level rise, which is already inundating low-lying islands and valuable wetlands; on changes in precipitation and air temperature, which will affect everything from agriculture to asthma; and on the shift in seasons and habitat that will make life difficult for trees, butterflies, and the other wildlife we are familiar with.
Enormous threats indeed. And it is perhaps inevitable that we are focused on the land and our fellow terrestrial inhabitants. But let us not forget the fact that we are changing the ocean profoundly in many ways. A recent study suggests that over a third of the entire ocean is heavily impacted by human activities, and that there is no longer a single patch of seawater anywhere that can be said to be pristine. And incredibly, we are not just affecting patches of the ocean here or there – we are changing the very chemistry of the seas, chemistry that has remained stable for millennia and which defines the parameters for life in the sea and also for the habitability of the planet for us.
All living systems are buffered from extreme change by their chemistry. If not for the carbonate/bicarbonate and other buffering chemicals in our blood, the pH (a measure of acidity) would fluctuate wildly and none of the myriad proteins or enzymes essential for life would function. Because pH is a logarithmic scale, very small changes in pH can be disastrous for life – for example, a change of less than one pH unit is lethal to humans.
The ocean is a gigantic living system, and is perhaps one of the best-buffered systems on the planet. Enormous quantities of buffering chemicals have been entering the ocean each year for billions of years. Remarkably, though, even the ocean is not impervious to the impacts of fossil fuel combustion and carbon dioxide emissions.
As atmospheric carbon dioxide concentrations have risen, the ocean has steadfastly taken up about 2 billion tons of it every year, protecting us from an even more serious climate crisis than we have already. However, carbon dioxide reacts with seawater to create carbonic acid. As a result, while the pH of the ocean varies widely in response to local conditions, scientists have detected a noticeable drop in pH (an increase in average acidity) over the last 20 years and project a decrease in pH by 0.3-0.4 units – a huge change - by 2100 if nothing is done to reduce carbon dioxide emissions.