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Climate Change, Cetaceans, and the Gulf of California

In Baja, Ecology Project International's home base in Mexico, the turquoise crescent of the Gulf of California is framed by desert—an impossible contrast of translucent waters against a wind-sculpted rockscape. At first glance, you might think it was empty of life, but under the surface of the water is a vibrant jungle. Eight hundred species of fish thrive here—77 of which are endemic, meaning they are found nowhere else on earth. Nearly 5,000 species of invertebrates, from bristling sea stars to iridescent mantis shrimp, creep along the bottom or float in the current. 

Around 70 million years ago, near the age of the extinction of dinosaurs, the Colorado River was born. As it grew, it channeled trillions of gallons of fresh water and nutrients into the growing Gulf of California. In the past century, however, the development of the Hoover and Glen Canyon Dams among others, have reduced the influx of fresh water and nutrients from the Colorado River to the Gulf of California to virtually nothing.

The damming of the Colorado dried up the ancient estuarine system of the former delta, and the rich habitat it provided for birds, fish, and crustaceans. But for now, because of its deep reserve of nutrients, the Gulf of California remains a special haven for marine mammals, particularly cetaceans. Blue, gray, sperm, pilot, and humpback whales all breed, calve, nurse, and feed in this calm oasis. There is even an unusual year-round resident population of six hundred fin whales, and the smallest (and most endangered) cetacean, the vaquita porpoise, calls the Gulf of California home.

Climate change will warm and acidify the Gulf of California, and how the base of the marine food chain—plankton—will change in this region is unknown. Over the past two decades, the length and frequency of harmful algal blooms (HABs)—sometimes referred to as red tides—have increased steadily in the Gulf of California, in large part from fertilizer run-off from agriculture. In 2007, a neurotoxin-producing HAB in the Gulf of California killed 100,000 lobsters, among other sea life. 

Globally, nontoxic phytoplankton populations are ebbing due to climate change, and where those populations reside is changing. The tiny shrimp known as krill, the main food of many cetaceans, eat phytoplankton and their populations are down as much as 70-80% in the Arctic. Many krill species hide, eat, and mature under sea ice. What effect is this having on cetaceans migrating annually to the Gulf of California?

Right now, only about 8% of the Gulf of California is protected, and only 1% of those areas are "no-take." The majority of Mexico's fisheries happen here, producing at least half of all seafood caught or raised in the country, from farmed shrimp to wild tuna. Illegal fishing is a major issue that threatens fish, marine mammal, and sea turtle populations, and a recent boom in aquaculture is also disrupting the balance of the natural ecosystems.

The first step to protect more of the Gulf of California - and the incredible fauna that live there - is research.

Last year, in boats with local researchers, local Ecology Project International (EPI) students identified nearly 2,200 cetaceans. The data they collected will be used to help the establishment of a new humpback whale refuge in the Gulf of California, bringing some security to cetaceans at the southern end of their migration for breeding, calving, and nursing.

Protecting whales means also protecting the benefits they offer to ocean ecosystems and carbon absorption. Giant cetaceans diving down into the ocean stir nutrients from the deep to the surface, nutrients that feed carbon-sequestering plankton, among other animals. Secondly, whales' waste, called "fecal plumes," provide nutrients to marine plants, which also pull in carbon through photosynthesis.

Local and visiting Ecology Project International students are also working on a study of benthic marine invertebrates (interesting little creatures that live on the ocean floor). Remember those nearly 5,000 species of invertebrates in the Gulf of California? That's a lot of creatures to monitor! Researchers are working on developing an eDNA technique that would allow a quick water sample to reveal which marine invertebrates are present, but they are still monitoring the process for accuracy. So, EPI students snorkel to identify the marine invertebrates in an area, and their data is compared with the eDNA identified in a water sample they take. eDNA will offer an incredibly efficient environmental monitoring technique, and EPI students are playing a key role in helping to develop it.

Climate change awareness and response are built into all aspects of the Baja Coastal Ecology Program. EPI local and visiting students have devoted curriculum time to creating and developing climate change solutions together, finding inspiration in the landscape and each other. EPI Baja Teacher Fellows have worked on a variety of projects, including sea turtle and water quality monitoring with local fishermen. And EPI alumni in Mexico are very active—their local eco club, the Californios Verdes, held 135 workshops, events, and rallies to help spread conservation awareness just last year.

There is no doubt that climate change will alter the lush underwater ecosystems of the Gulf of California, but EPI students and alumni are helping researchers and the public work to protect the creatures that find sanctuary there. You can also learn about how EPI students are helping climate-threatened species and ecosystems in Yellowstone, Belize, and Costa Rica on our blog. 

Will you consider supporting our students' work? Visit our Connect4Climate campaign page to learn more, and donate to EPI.


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