A Rice’s whale was just one of the rare sightings researchers found on the 2-month-long expedition.
A recent expedition along 3,400 miles of deep waters in the northern Gulf of Mexico could be the key to restoring the populations of some of the world’s most precious marine mammals and birds. On June 22, a group of scientists aboard the National Oceanic and Atmospheric Administration’s (NOAA) Gordon Gunter ship embarked on the first of two surveys collecting data on the abundance of sea mammals and seabirds existing in the Gulf.
“The best part is getting to be offshore and the chance to experience the unexpected. Also seeing something new for the first time,” said Jesse Wicker, a marine mammal scientist. “The cruise overall had amazing weather conditions which was an added bonus.”
During the 2-month-long journey, which concluded in August, scientists divided into three teams each with its own focus and duties. Together, they were able to document nearly 400 marine mammal sightings among 20 species and record thousands of seabird sightings from 22 species. Among the most rare creatures encountered was a Rice’s whale discovered in the northeastern Gulf. A critically endangered native Gulf species, Rice’s whales were first recognized as a new species in 2021, relatively little is known about Rice’s whales. In July, a Texas fisherman also spotted a Rice’s whale in Galveston, though it’s unclear if it is the same one recorded by the Gordon Gunter.
While some scientists kept visuals of the Rice’s whale, other scientists working inside the ship used underwater microphones, known as hydrophones, to record its vocalizations. “The Rice’s whale has a very low frequency, so their sounds get muffled with the sound of the vessel,” said Shannon Merkle, an acoustician on the survey, in a statement. “It is challenging to hear them from the vessel. So, our team deploys SoundTraps to gain acoustic information on the species.”
Learning about the Rice’s whale can help reduce the impacts of human activities on the species, which include vessel collisions, oil spill impacts, noise impacts and fishery entanglements. “Getting multiple, clear photographs that identify the Rice’s whale is critical to our knowledge of this endangered species,” said Tony Martinez, chief field scientist, in a statement. “Making accurate identifications and expanding our knowledge about the species helps us to protect the population.”
Another “special treat” for scientists on the trip was a sighting of a Fraser’s dolphin. While not considered endangered, the marine mammal was far away from home as they are native to the deep waters of the Pacific Ocean. During the voyage, sperm whales had the most individual sightings. However, in terms of number of animals, the survey observed more dolphins, including bottlenose and those belonging to the genus Stenella, such as pantropical spotted dolphins, Atlantic spotted dolphins, Clymene dolphins and spinner dolphins.
Among the avian variety, the most widely detected species were the Audubon’s shearwater, band-rumped storm-petrel, sooty tern, and brindled tern. Visual teams using handheld binoculars would work outside on the steel deck of the ship—which can get as hot as 150 degrees Fahrenheit—from sunrise to sunset searching for animals. “Probably the biggest challenge for seabird observers is remaining in alert search mode for long periods, especially when there are no birds around,” said Christopher Haney of Terra Mar Applied Sciences. “We mitigate this by striving to keep watches to an hour or less, especially in very hot weather.”
Identification challenges were also a big issue for scientists, as seabirds are notorious for having clusters of 2-3 species that look virtually identical, Haney explained. “Observers need much experience, and be able to use really subtle features like shape and flight style,” he added.
Being away from home for such long periods of time also wasn’t easy for scientists. “Most people are shocked to learn we do not take weekends off while at sea which can be challenging,” Merkle said. “In our off time we try to mitigate sleep, balance our desk jobs, and try to get in that workout and socialize to keep up morale. I enjoy the camaraderie of the science team and the ships’ crew.”
Data from the expedition will help scientists update population models to inform long-term conservation and management of marine mammal and seabird populations in the Gulf. NOAA said this will help improve information available for natural resource managers as they try to limit the risks to these animals. The study will also help improve restoration planning to benefit species that were harmed during the 2010 BP Deepwater Horizon oil spill—the largest marine oil spill in history. The data from the survey will be analyzed after the second ship survey, which is slated for next summer.