Lauren Rust spoke with us on June 30th at Green Apple Books. She came to talk to us about her work at the Marine Mammal Center, the research they do, and the animals they attempt (and don’t attempt) to rescue.
The Center covers 600 miles of California Coast from Mendocino down to around San Luis Obispo. They care for around 500 animals/year. They might stay up to six months, but usually an animal’s stay is a few weeks to 3 months. 50% are released and 50% end up dying or being euthanized, a few end up in zoos (healthy animals that otherwise can’t be released, for instance if they were blind). They have a big pool for cetacean’s like dolphin’s but usually they serve as triage pass them on to others for longer care.
Their most common animals are California Sea Lions, Harbor Seals, and Elephant Seals. Guadalupe and Northern Fur Seals, and Stellar Sea Lions are less common to the Center.
The number of animals they have taken care of over the years has grown since their start in 1975. Their peak year thus far was in 2009 when their new facility coincided with an outbreak. 2015 is close to those numbers and will likely surpass it.
The reason for that is the large numbers of starving young sea lions washing up on California shores. The reason for this influx is water temperature — a patch of warm water known as “the blob” that has been bobbing off the coast of California since 2013 and is now hugging it. The effect of that water has been to inhibit upwelling, which means less phytoplankton, which means less zooplankton, which means less fish, which means… problems for sea lions.
California Sea Lions have taken the biggest hit because of a number of reasons. Although they range the whole western coast of the U.S. down along Mexico, they give birth in only a limited number of rookeries the furthest north being the Channel Islands.
77% of breeding females give birth each year to a pup (they are polygnous with one male to many females) and gestate for 9 months. The mother spends the first few days ashore with their ~7kg babies but then start to make foraging trips, finding their pups by vocalization when they return to shore. The mother nurses them for 6-11 months. It’s not easy being a seal mom!
What happens with this is that the warm water, having kept the fish away, keeps the mother further and further away from her pups. Eventually the pups take to the water, seeking food, and then wash up malnourished onto mainland shores (the vast bulk unsuprisingly were in Santa Barbara). This started happening in Dec of this year — in a normal year a pup would have been nursed through May. Researchers on the Channel islands have seen lower birth rates and mothers having a harder time catching food.
600 pups have been admitted, given fish milkshakes as well as subcutaneous fluids with suppliments and anti-parasites (sea lions typically have parasites they have picked up from fish, so they try not to treat them too much). Eventually they are worked up to food, and one of their conditions of release is that they eat free food.
One lesson learned this year given the numbers of malnourished patients, not giving the pups too much — spaing it out or just giving less. It sometimes takes the pups a while to figure out what to do with fish. They’ll drag a fish on a line to simulate swimming (most the of the fish is frozen), or sometimes drop a live fish in to simulate.
Once they’ve gained weight, have clean bloodwork, and eat alongside others, they get a flipper tag and are released (sea lion pups are usually taken south, seals are relased near chimney rock on Point Reyes — never on a public beach — and elephant seals where there are rookeries).
Elephant Seals and Harbor Seals tend to be much younger patients, from premies to a few days old, and require a bit more attention and time at fish school (the california sea lions often have some experience with fish in the wild).
Other reasons for the mass strandings this year have been considered, radiation, ocean health, contaminants, and other human interactions, but other marine mammal species have not been equally affected and the big problem has been with pups. Elephant Seals and Harbor Seals have different life cycles, both with much shorter periods to nurse.
Malnutrition is what brings most patients into the Center, the next leading cause of strandings is Domic Acid Toxicity. This is cause by the algae of red tides, which is eaten by fish, and then by sea lions. Its effects in sea lions are memory loss, brain damage, reproductive failure, and seizures similar to epilepsy. Sea lions will shake, and wave their heads and flippers, eyes shaking. They can be confused and aggressive in this situation.
These animals are treate with anit-seizure medications for about 10 days. Cronic cases with brain damage are euthanized.
Lauren’s main job is not care but research, so she spends a lot of time to necropsies. This research supports over 40 projects from different scientists each with their own set of criteria: age, sex, death, time of death. They might send on eyes, kidneys, lymph nodes, cells, skin for genetics, teeth for knowing age (teeth have rings — something they are validating against known tagged animas), or parasites to one researcher or another. Skeletons go to the California Academy of Sciences.
One of things the Center has been studying is one of the leading causes of death in adults… carcinoma. 18% of the adults admitted die from this, mostly females. Since 1998 they’ve putting together samples of dead females with cancer, and females without, with a goal of 300 each (they are at 130), with a goal of learning more. Herpes virus seems to be a corallary, but they are hoping to have a better understanding of its causes.
They do also do research on live animals — but only opportunistically — by taking samples in the course of routine care, getting a little bit of extra blood, urine, and hair for things like mercury samples, and doing nasal and rectal swabs. All released animals get a tag, and they occassionally place satellite tags but these are expensive.
One goal of the research is to have create the MMHMAP: marine mammal health monitoring and analysis. Mappng causes of death in marine mammals and cetaceans and correlating that with ocean health (like temperature and the like).
Another bit of research they participate in is whale strandings. This is the California Academy of Science’s bailiwick, but with large whales they often need all hands on deck to help do necropsies. About 25 or so strand per year with around 5 being larger whales. This year has seen a slight uptick (a couple of humpbacks, a grey, one entangled killer whale, and a rare sperm whale in pacifica, one of two whales there this year), but there seems to be no common thread other than there being more animals offshore.
The necropsies look for cause of death: broken bones, hemmoragging in the muscle. Age can sometimes be gleaned from the wax in the earbone, but it is not always accessible or easy to read. Most deaths are either some sort of traume or disease, but larger number are unknown. The good news is that this research has already informed boat operation — reduced vessel speed and changed vessel lanes.
And that’s the goal of all this research — to make things better for marine mammals. The Center’s particular research comes back to treat future patients, so even patients who don’t make it play a part.
You can learn more about the Marine Mammal Center’s work, or even help take care of them (a lot of the work is done by the hands of volunteers) visiting http://www.marinemammalcenter.org
SF Natural History Series 