Sea of Cortez: Conserving the World’s Aquarium

Where the Sonoran Desert meets the ocean: the Sea of Cortez. Photo: © WIll Heyman/TNC

Where the Sonoran Desert meets the ocean: the Sea of Cortez. Photo: © WIll Heyman/TNC

By Alison Green, senior marine scientist

Imagine an impossibly beautiful place where the Sonoran Desert meets a clear blue ocean that is teeming with life – colonies of playful and mischievous sea lions, flying mobulas (manta rays that leap out of the water) and endemic species of reef fishes (that only occur in that part of the world), large colonies of seabirds nesting and soaring overhead, humpback whales breaching, and blue whales and large schools of dolphins cruising past.

That is the Gulf of California, also known as the Sea of Cortez, and it is one of the most rich and spectacular marine environments on earth — so much so that it inspired Jacques Cousteau to call it the “Aquarium of the World.”

Recently I had the great privilege of visiting this amazing place, and snorkeling with many of its famous inhabitants.

One day we cruised out to Isla Espiritu Santo, a biosphere reserve, to see what awaited us out there.

Flying mobula. Photo: Alison Green

Flying mobula. Photo: Alison Green

On the way out to the island we were surrounded by large groups of flying mobulas, which were leaping out of the water all around us.

They are a small species of manta ray that jump more than other mantas do. Scientists are not sure why they do that – it is just one of many mysteries in the Sea of Cortez. (This video shows the spectacle well).

Perhaps they do it to escape a potential predator, or as part of a courtship ritual, or to rid themselves of skin parasites?

At one point we actually managed to jump in the water with a group of about 50 or so of them, and we could see them swirling around each other and racing towards the surface. So it was easy to see how they could just keep going and leap out of the water.

Snorkeling with sea lions. Photo: © Mark Godfrey/TNC

Snorkeling with sea lions. Photo: © Mark Godfrey/TNC

We also snorkeled with the playful (and sometimes a little-bit-scary) California sea lions at Los Islotes – a group of small islands off Isla Espiritu Santo.

The sea lions darted around us in small circles and sometimes raced up to us at great speed – screeching to a halt just inches away from us. Although occasionally one of the males got a bit territorial and menacing – like the one who chased us out of the water and back into the boat.

It was a bit scary, but that just added to the excitement of being there.

But by far the best part was when I saw a playful young sea lion sneak up behind Diana Bermudez, who leads our Baja Marine Initiative, and bite her on the bum!  I laughed so hard I almost drowned.

Ensuring a Future for the Sea of Cortez

Commercial fishing is a major driver of the local economy. Photo: © Mark Godfrey/TNC

Commercial fishing is a major driver of the local economy. Photo: © Mark Godfrey/TNC

But it’s not all fun and games. The Gulf of California is not only a beautiful place, but the outstanding marine environment provides significant ecosystem services to the people.

This region supplies 70% of Mexico’s fisheries, and is an important area for both commercial and sport fishing.  It is also a major destination for tourism.

While fishing and tourism are the major economic drivers in the Gulf, and they provide important income and livelihoods for local people, they also provide the greatest challenges for conservation and management in terms of overharvesting of marine resources and unsustainable coastal development.

In 2012, the Conservancy and partners launched the Baja Marine Initiative to transform ocean management and help bring 10 million hectares of the Gulf of California and the adjacent Northern Mexico Pacific under protection or effective fisheries management.

In the past, the Conservancy’s focus has been supporting the establishment and effective management of federal protected areas as a primary tool for biodiversity conservation in this region.

However, to date only 7% of the region is protected and less than 0.5% is a no-take area, so there is a lot more work to do.

The Conservancy is now scaling up our work in the region to address the full range of challenges and opportunities by broadening our approach to work with other sectors (particularly fisheries and tourism) to develop an integrated planning and management framework for the region where conservation, food security and economic development goals can be achieved simultaneously for the benefit of people and nature.

Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.

Posted In: Marine

Dr. Alison Green is a senior marine scientist with The Nature Conservancy’s Indo-Pacific Division. Alison has 25 years’ experience in coral reef conservation and management, and her areas of expertise include coral reef fish ecology, marine spatial planning, and monitoring and measuring the effectiveness of marine conservation. Since Alison started working with the Conservancy 10 years ago, she’s provided scientific advice and training to field practitioners in marine conservation in over 20 countries in the Western Pacific, Southeast Asia, West Indian Ocean, Latin America and the Caribbean. Currently, she is focused on providing scientific advice for marine spatial planning in the Coral Triangle, Micronesia and beyond. Alison is an Aussie who lives in Brisbane, Australia. You can read Alison's previous blogs on Conservancy Talk. (Photo Credit: Emre Turak)

Comments: Sea of Cortez: Conserving the World’s Aquarium

  •  Comment from michael Harris

    So nice to see all the good work i am always inspired to see what you are doing.
    All my Best Wishes

    •  Comment from Alison Green

      Thank you Michael.
      It was your Dad Stan Harris who inspired me to work in conservation in the first place.

  •  Comment from George Maina


  •  Comment from gabriela layi

    I visited the Sea of Cortez long time ago and your blog makes me want to go back! would love to see the nobulas. Great to hear of your work there. best, gaby

  •  Comment from Alica Dyring

    It’s a beautiful & charming place. All the sights are too wondering. Video of large groups of flying mobulas under the sea and all the post are so good. Thanks for this kind of Blog.

  •  Comment from thorne

    While I find the footage of the rays incredibly beautiful the Sea of Cortez eco system has been and continues to be in decline for 40 years. I have swam underwater off Espirtu Santo gliding over hundreds of carved up carcasses of these creatures. Over the past 25 years I have travelled the Baja coastline extensively and the reality is that the conservation areas are completely ignored with zero enforcement.

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