SHIPOWNERS can expect new expensive demands from environmentalists as new studies show that the threats of underwater ship noise makes life unbearable for whales and dolphins, reports UC San Diego Today.
Researchers at the University of California San Diego's Scripps Institution of Oceanography have been auditing marine environment for decades to study the ecology of marine animals and the threats they face, said the report.
Through high-frequency acoustic recording packages (HARP) the Scripps Whale Acoustics Lab record everything from whale songs and dolphin clicks to passing ships and military.
The lab in collaboration with Maersk, with funding by the National Resources Defense Council, have found that human-made underwater noise in the ocean can negatively impact marine organisms that rely on sound for daily life functions.
Said Scripps PhD student Vanessa ZoBell, lead author of the study: "We need all hands on deck to establish solutions for the modern ocean."
The research collaboration emerged following Maersk's completion of a US$1 billion, five-year "Radical Retrofit" initiative focused on improving energy efficiency and fuel consumption to reduce emissions.
During this effort, 12 of Maersk's G-Class containerships were retrofitted from 2015 through 2018. Changes made to the sister ships included a redesign of the bulbous bow to reduce drag, reducing the engine's output to improve vessel efficiency at slower speeds, reducing the number and size of propeller blades, and more.
While the primary goal of the retrofitting effort undertaken by Maersk was to increase fuel efficiency, both Scripps and Maersk were interested in exploring noise reduction as a potential of the effort.
"Underwater noise is increasingly recognised as an important environmental factor," said Maersk's North American sustainability chief Lee Kindberg.
"It is clear that we need additional info to reduce underwater noise and greenhouse gas emissions," she said.
The study identified retrofit-induced changes in the ships' radiated noise levels. In commercial ships it is predominantly the sound from propellers or pressure-related water cavities due to propeller motion.
Researchers focused on 111 transits from the 12 sister ships, pre- and post-retrofitting, as they made their way to and from the ports of Los Angeles and Long Beach. Marine animals including humpback whales, blue whales, fin whales and dolphins were also recorded at the study site.