In recent years, there has been concern that man-made noise may be a cause of stress for dolphins, whales and other marine mammals, but the results of a five-year study show that noise pollution – especially noise generated by seismic airguns during geophysical exploration for oil and gas – seems to have minimal effect on endangered sperm whales in the Gulf of Mexico, say researchers from Texas A&M University who led the project and released their 323-page report today at the Houston Museum of Natural Science.
The multi-year $9 million study, the largest of its type ever undertaken and formally titled Sperm Whale Seismic Study in the Gulf of Mexico, was conducted by the Minerals Management Service and featured cooperation with the Office of Naval Research, the National Science Foundation and the National Fish and Wildlife Foundation. The project brought together researchers from eight universities, but it was managed overall by Texas A&M's Department of Oceanography, with research scientist Ann Jochens and professor Doug Biggs serving as principal investigators.
"The bottom line is that airgun noise from seismic surveys that are thousands of yards distant does not drive away sperm whales living in the Gulf," Biggs explains.
"However, some individual whales feeding at depth reduced the rate at which they searched acoustically for their prey when scientists carried out controlled exposure experiments by bringing seismic surveys close by the whales. As a result, the oil and gas industry has agreed to a best-practice attitude that seismic surveys should shut down temporarily when towed airguns come within one-third of a mile of whales or groups of whales in the Gulf."
Though not often seen, sperm whales are regular visitors to and residents in the Gulf of Mexico. They are the largest of all toothed whales and can reach lengths of 60 feet or more and live 60 years or longer. Their primary diet is squid and fish and they have been known to dive as deep as 7,000 feet. Humans no longer hunt them for their oil, but the whale in Herman Melville's classic novel Moby Dick was a sperm whale.
Sperm whales are not often seen because they prefer to stay in the deep waters of the Gulf, usually in depths of 3,000 feet or more and at least 150 miles offshore, Biggs says.
"Sperm whales go to where their food source is, and that means very deep water. So folks that do see them are marine mammal observers who ride the seismic survey vessels and the workers on the big oil and gas rigs, and even that does not happen often," Biggs adds.
The primary concern facing the scientific research group was noise – there's more of it in the world's oceans than you might think. A study by the Scripps Institution of Oceanography shows that the world's oceans are 10 times noisier since the 1960s, and at any one time, there are as many as 30,000 ships circling the globe.
Biggs says that over the course of five summers, 98 sperm whales were tagged with devices that relayed back critical data such as measurements about sound levels and behavioral aspects of whales, including tracking their movements. Of particular concern was the effect that loud low-frequency noises, such as those created by seismic activity, might have on sperm whales in the area.
Oil and gas companies prospect for subsea reservoirs by firing air guns during their seismic work, which government regulators thought might negatively affect sperm whale behavior. Also, the sheer volume of work being done in the Gulf was another concern: The Gulf of Mexico accounts for almost 70 percent of the oil and gas extracted from U.S. waters and there are thousands of oil and gas platforms in the region.
But the study found no unusual effects of controlled exposure to seismic exploration on the swimming and diving behavior by sperm whales in the Gulf, and also revealed a wealth of data about sperm whale biology and habitat.
"We now know that the sperm whales in the Gulf appear to be their own distinct stock – they show genetic and social differences from other sperm whales around the world," Biggs says.
"There are believed to be about 500 to 1,500 sperm whales that reside in the Gulf. Most of these are family groups of females and maturing young. When one family group socializes with another family group in the Gulf, they make very distinct sounds. Even though the family groups are visited by males that come into the Gulf from other oceans, their 'clicking' sounds, called codas, the Gulf sperm whales make appear to be different from most others made by sperm whale groups in other parts of the world.
"The five-year study has greatly contributed to our knowledge of sperm whales, especially those found in the Gulf of Mexico. It's also raised new questions we need to know more about, such as their feeding and breeding patterns. There's still a lot we don't know about these huge creatures."
Keith Randall | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences