Seattle Aquarium bird and mammal team members Julie Carpenter and Mariko Bushcamp recently traveled to The Marine Mammal Center in Sausalito, California to assist in the care and rehabilitation of sick and injured marine mammals. The Marine Mammal Center is a nonprofit research hospital and educational center dedicated to global conservation of marine mammals through their rescue and rehabilitation work, as well as educational outreach and scientific research efforts.
Julie and Mariko were able to assist in important rehabilitation efforts, learn more about the West Coast marine mammal stranding network, and bring back a wealth of knowledge to the staff and visitors of the Seattle Aquarium. Through this collaborative relationship, we hope to continue to educate people about the critical work being conducted at The Marine Mammal Center and the many environmental issues affecting marine mammals.
Learn about Julie and Mariko’s experience in this five-part blog series.
Part 1: An opportunity to assist at The Marine Mammal Center
Part 2: Northern elephant seals
Part 3: California sea lions, northern fur seals and Guadalupe fur seals
The U.S. population of California sea lions is currently estimated to be around 300,000 animals, all on the Pacific coast. According to wildlife biologists, the species is now at “carrying capacity”—near the highest level the environment can sustain. California sea lions are the most common marine mammal patient at The Marine Mammal Center. Although the population of Guadalupe fur seals is increasing, the species is still listed as depleted under the Marine Mammal Protection Act (MMPA) and are listed as threatened under the Endangered Species Act (ESA). Northern fur seal wild populations are decreasing by four to six percent each year and they are also listed as depleted under the MMPA.
The daily care and medical needs of sea lion and fur seal pups are similar to that of elephant seal pups, but a more gentle yet quick approach is needed to accommodate their small size agility, and natural aggressiveness. Animals requiring tube feedings receive thinner tubes and staff providing restraint must be conscious of the animals’ large and delicate flippers. Animals are usually placed into kennels for weigh-ins due to their ability to rotate their rear flippers underneath them, which allows them to run quickly.
Many of these animals suffer from malnourishment due to their inability to find the fish stocks that were once plentiful. Research shows that overfishing and warming ocean waters associated with an El Niño could be major contributors to the declines in local fish populations. Entanglement in marine debris is another major cause of marine mammal strandings. According to a multiple-year study published in 2014 in the scientific journal PLOS ONE, it is estimated nearly 270,000 tons of plastic is floating in the world’s ocean and that plastic is broken up into more than five trillion pieces.