Seismic Blasting and Cetaceans
There’s been a lot of noise lately about seismic testing in the oceans.
Seismic airgun testing is a method of searching for offshore oil and gas deposits, but many worry that this method of testing the ocean floor comes with potentially lethal consequences for marine life. The U.S. Department of Interior’s Bureau of Ocean Energy Management (BOEM) recently released their Environmental Impacts Statement (EIS), three years in the making, that outlines measures for reducing the impact on marine life that are especially sensitive to the powerful sound impulses used to search for energy resources beneath the seafloor.
Photo courtesy of Pacific Gas and Electric
Seismic testing and its effects have long been a contentious debate between politicians, the energy industry, and environmentalists concerned for the well-being of marine animals sensitive to loud sounds in the oceans, especially whales. Politicians have long been pressured by governors in states adjacent to the Gulf of Mexico and the Mid- Atlantic to approve oil and gas exploration in the Atlantic, which has been on hold for 26 years. The area to be surveyed reaches from Delaware to Florida, a region recently designated by NOAA as critical habitat for North Atlantic Right Whales, whose remaining population is currently less than 500 individuals.
Photo courtesy of Trilogy Excursions
The recently completed EIS found that there would be “minor to negligible” impact to most wildlife, with the exception of marine mammals and sea turtles, for which impact could be “moderate.” The statement estimates that about 138,000 marine animals could be injured in some way, and the seismic testing could disrupt the migration, feeding, or other behavior of 13.6 million marine animals. It’s known that marine animals use sound in the ocean for reproduction, food- finding, navigation, communication, and sensing their environment.
Photo courtesy of NOAA NMFS
The species most likely to be injured by seismic testing are right whales, humpback whales, other odontocete cetaceans such as dolphins, loggerhead, leatherback and green sea turtles; and migratory pelagic fishes such as tuna and billfish. Recent numbers of tuna catches off Namibia have dropped precipitously after seismic testing exercises were done in the same area. It’s thought that fish larvae and eggs can be killed by very intense sound, as well. Right whales and humpback whales will likely be impacted by seismic testing in the Atlantic, though not much is known about the details of how sound affects baleen whales. The National Marine Fisheries Service (NMFS), a division of NOAA, is in the final stages of a 15-year research program on how marine mammals are disrupted by sound, though the current EIS is slated to be finalized by the Obama administration before the results of this study will be available. It is thought that seismic testing has led to gas bubble disease and intracranial bleeding found in mass strandings of deep diving beaked whales in the Atlantic.
Photo courtesy of New England Aquarium
Though it is difficult to tie seismic testing directly to strandings and marine animal death, it is clear that more needs to be known about the effects of loud sounds in the ocean on sensitive animals, especially when there are less than 500 individuals of a species left in the world, before widespread seismic blasts are approved to go ahead in our oceans. To learn more and to take action, consider signing a petition or writing a letter to your elected representatives- remember it is their job!
By: Kelly Montenero