Over 60 whale skeletons have been discovered submerged in the waters off Los Angeles, surpassing the total number of skeletons found worldwide since 1977.
Eric Terrill and Sophia Merrifield, marine scientists from the Scripps Institution of Oceanography at the University of California San Diego, led a research team conducting surveys in 2021 and 2023 to assess waste levels over a 350 km2 area of the seafloor off the coast of Los Angeles, California. In addition to numerous barrels of hazardous waste, they also uncovered a significant number of whale bones, reported Smithsonian on July 20.
A whale skeleton submerged off the coast of California. (Photo: Ocean Exploration Trust/NOAA)
The phenomenon of dead whales sinking to the ocean floor is known as “whale fall.” Whale falls create biological oases in nutrient-poor seafloor environments, providing food and habitat for a variety of organisms, including hagfish, sleeping sharks, microorganisms, clams, mussels, worms, roundworms, crabs, and jellyfish.
During the survey, 7 whale skeletons were confirmed off the coast of Los Angeles, with the total likely exceeding 60 skeletons, surpassing the previously recorded amount of whale bones found globally since 1977, which was 50. The newly discovered skeletons belong to gray whales, blue whales, humpback whales, fin whales, sperm whales, and minke whales, according to Greg Rouse, a marine biologist at the Scripps Institution of Oceanography. Craig Smith, a retired marine scientist from the University of Hawaii, mentioned that the quantity of bones is 3 to 5 times what he had estimated.
Several factors may explain the research team’s discovery of such a large number of whale bones. First, this is the highest resolution survey ever conducted in an area of this size. The lack of oxygen in the water may also contribute to the preservation of a considerable amount of bone. In low-oxygen environments, the biological and microbial processes that decompose whale bones occur very slowly. Another factor is that there are no rivers flowing into the ocean nearby, resulting in less sediment covering submerged objects such as whale bones.
The research team also believes that it is less likely that hazardous waste and weaponry are responsible for killing whales in this area. Instead, increased maritime traffic may result in a higher number of whale deaths due to ship strikes compared to other areas. Thousands of gray whales migrate through these waters each year, and blue whales frequently feed here, according to John Calambokidis, a marine biologist at the Cascadia Research Collective.
Experts at the Scripps Institution of Oceanography plan to return to the waters off Los Angeles with remotely operated vehicles to collect additional images and videos of the whale falls, which will help identify species and possibly search for signs of ship strike injuries. Smith and Rouse also aim to collect whale bone samples to investigate the causes of death as well as their life history.
The large number of whale falls presents scientists with an opportunity to further understand the food web and the lives of organisms that depend on them. They may also reveal additional insights into the role of decaying whale carcasses in the ocean’s carbon and nutrient cycles.
