Elephant Seals, El Nino & Domoic Acid Poisoning
Hello, my name is Ellie, and I’m an Elephant Seal. I’m excited because I’ll become a mother soon. I’ve been pregnant for eleven months. I’ve come to Ano Nuevo, off the central coast of California, USA. Here there’s what we call a rookery, where elephant seals hang out on the beach. We spend up to ten months a year at sea, so being on the beach is a vacation for us. Well, maybe not for the mothers who have to protect their pups and produce milk that contains up to 50 percent milkfat (human breastmilk is only 4 percent fat).
I feel the pup coming. I push, push and push until plop! My daughter is born! I clean her up by licking her. She’s already vocal, probably because she’s hungry. We have a special call to one another so we can be reunited if separated. The beach is crowded-there’s a lot of elephant seals here.
I worry that some male will bowl over my pup, or my pup will get in the way during one of the dominant male’s battles with rivals. Otherwise our days here will be blissful; sunning ourselves in the sun, nursing, and dozing off. I won’t wean her for four weeks, and after five weeks I’ll mate and finally return to the sea to feed.
Sigh, I’m not looking forward to returning to sea. Sure I’ll be famished, but the food fish just aren’t here. Usually, in a non-El Nino year, there is plenty of food. That is due to something called upwelling, which occurs off parts of the west coast of the Americas. Upwelling is when cold, nutrient-rich seawater comes up from the deep ocean onto the surface. Plankton, microscopic plants and animals that make up the beginning of the food chain, feast on the nutrients. The fish, that I eat, find plankton to eat.
In a non El Nino year, the trade winds blow west warm seawater from the Eastern Pacific Ocean (the west coast of the Americas) to the Western Pacific Ocean (Asia). This allows the cold nutrient dense water that dwells in the deep waters below to replace the warm surface water that was blown away west. This is what causes upwelling along the west coast of the Americas. In contrast, during an El Nino year, the trade winds stop and the warm water stays in the Eastern Pacific Ocean. Warmer water means no upwelling, less plankton, and therefore less fish for me to eat.
To boot, once I find food there’s a horrible toxic algae called Pseudo-nitzschia australis in it. Domoic acid poisoning has neurological effects on animals that eat food contaminated with it. According to the Marine Mammal Center in Sausalito, California, USA, “About three-quarters of the California sea lions at our hospital are suffering from domoic acid toxicity, which primarily attacks the brain, causing lethargy, disorientation, seizures and if not treated, eventually, death.” Recently the Dungeness crab season has been canceled because of this algae. This algae is also responsible for the red tide seen periodically off the coasts that closes shellfish fisheries.
It’s an uncertain world that my daughter will face. I hope she can survive to a few years old to have pups of her own.
