“Balloon straight ahead” one of my researchers tells the captain while leaning forward from the bow of our boat. We are so accustomed to find plastic debris during our dolphin surveys off Los Angeles, California, that a party balloon is the first thing that comes to everyone’s mind when we come across something round-shaped floating just below the ocean surface. We are still a couple of miles offshore, heading back to port after a long day recording data and taking pictures of two species of common dolphins, bottlenose dolphins, Minke whales and sea lions and the ocean is getting choppy. It’s time to go home.
Suddenly, our alleged balloon raises its head out of the water.
“Twelve o’clock, twenty meters. It’s a sea turtle, it’s a sea turtle!” yells another of my assistants as she lowers her binoculars and starts waving her hands to get our attention. It’s a sea turtle indeed: an endangered green turtle.
As the marine reptile slowly swims just below the surface, we parallel the animal to take a peek. The turtle lifts its head for a breath of air and we are all speechless.
In almost two decades of regular year-around monitoring of marine mammals in Santa Monica Bay we have never seen a single sea turtle! I’d heard that there were some rare sightings in the past and sea turtles have been found stranded along California shores, especially south of our study area, but in thousands of hours spent doing research inside the bay… no turtles. So, why now?
This species has been regularly seen near the mouth of the San Gabriel River, one of the main watersheds of the Los Angeles Basin. In this highly industrialized area, a colony of green turtles have found “home” thanks to the unusually warm temperature of the water. Making the water particularly cozy for these animals are two large industrial electric power plants located near the rivers’ outlet. This lukewarm artificial habitat resembles, in a way, the more temperate-tropical waters in which these animals usually live. Walking along the bike path, one can observe green turtles as small as a dinner plate or as large as 4-feet in length. Not too many Los Angelinos are aware that these ancient-looking marine reptiles live year-round in this area, but some people come armed with binoculars for a turtle-watching day; a good alternative to the usual bird-watching.
This is their Northern-most colony. The majority of sea turtles, in fact, start to appear along San Diego shores and become more abundant as one goes south. Santa Monica Bay, with its relatively cold waters, hasn’t ever been a great location for green turtles to roam… except perhaps in this last month.
According to a recent report by the National Oceanic and Atmospheric Administration, the first six months of 2014 were the hottest ever in California, and ocean temperatures are currently going through a “remarkable” warming period. To many scientists this looks a lot like the beginning of an El Niño weather pattern even if there is still ongoing debate on this topic. Others believe the warming might be related to climate change. Whatever the reason might be, the warmer waters of the bay are having an effect on the distribution of different creatures living in the oceans, like sea turtles. In my study area off Los Angeles, this green turtle has not been the only recent odd encounter. Lately, our Ocean Conservation Society research team and other scientists along this stretch of California coast have recorded sightings of species not usually observed here. By-the-wind sailor jellyfish, sea nettles, sunfish, and subtropical fish are showing up with increased frequency.
Every time we go out for a research day at sea, we now seem to meet up with something unusual. What will come next?
Maddalena Bearzi has studied the ecology and conservation of marine mammals for over twenty-five years. She is President and Co-founder of the Ocean Conservation Society, and Co-author of Beautiful Minds: The Parallel Lives of Great Apes and Dolphins (Harvard University Press, 2008; paperback 2010). She also works as a photo-journalist and blogger for several publications. Her most recent book is Dolphin Confidential: Confessions of a Field Biologist (Chicago University Press, 2012).