To Fish or Not to Fish?

Part B: Gulf of California: Aquarium of the World

Marine Protected Areas in the Gulf of California. Map courtesy of the Atlas of Marine Protection.

Renowned ocean explorer Jacques Cousteau once called the Gulf of California the "aquarium of the world." Nestled between the Baja California peninsula and mainland Mexico, this strip of sea represents just 0.008% of the world's seas but is home to nearly 900 species of fish and 34 species of marine mammals. The high biodiversity of this region is due to its wide variety of habitats and complex geological and oceanographic history. The Gulf of California is also economically valuable, yielding approximately half of the entire fish catch for all of Mexico.

The Gulf of California, also known as the Sea of Cortés, has been referred to as a microcosm of what is happening to the world's oceans. In recent years, the rich biodiversity of this region has been threatened by the growth of economic activities. Decreased freshwater flow from the Colorado River, urban waste and agricultural chemical runoff, and destructive and wasteful fishing practices have resulted in the deterioration of the Gulf of California ecosystem. There are now 56 Gulf species on the World Conservation Union's endangered and threatened species list.

The richness and productivity of the Gulf of California marine ecosystem make it one of the world's top conservation priorities. Multiple protected areas have been established in this region to safeguard the inhabitants of the Gulf, the Baja California, and the neighboring mainland.

1. Watch a report on the Gulf of California, which shows several parks at various stages of setting up marine protection.

Conservation in the Gulf of California

2. Visit the IUCN World Heritage site on the Islands and Protected areas of the Gulf of California to read the 2017 report on the area.

Checking In

Answer the following questions to check your understanding of conservation issues in the Gulf of California.

  • What are the major threats to the Gulf of California?
  • What are some recommendations for conservation in this region?


Cabo Pulmo

One of the marine reserves in the Gulf of California is Cabo Pulmo. This 171 km2 MPA is located on the southeast coast of the Baja peninsula near a small village of the same name. Cabo Pulmo, which was established in 1995, contains the only Pacific coral reef in the Sea of Cortés.

3. Visit the Atlas of Marine Protection - Cabo Pulmo to see the map of Cabo Pulmo National Park and read about its restrictions and history.

4. Watch this short video to learn more about the history of Cabo Pulmo.

The Story of Cabo Pulmo

5. Read this article from 2011 Little Mexican reserve boasts big recovery about Cabo Pulmo. 

Checking In

  • About how long did it take for the numbers of sharks to increase significantly or "return" to Cabo Pulmo after the MPA was in place?
  • What is the estimated density of fish living on Cabo Pulmo's reef?

6. Watch this short video of oceanographer Dr. Sylvia Earle visiting Cabo Pulmo in 2016.
Sharks in Trouble

In order to have a successful MPA, there are many factors to consider -- from location to purpose.

7. Read the article How to Protect Sharks from Overfishing, which looks at how MPAs benefit sharks and other species and the challenges they face and must address. 

Checking In

  • What are some important components of a successful MPA?
  • What are some components that keep an MPA from reaching its conservation goals?

Stop and Think

2: Based on what you know, explain what you think made Cabo Pulmo a successful MPA, and explain what improvements could be made for managing it or other MPAs like it.

The next several labs will guide you through an in-depth look at some of the human activities and climatic changes that threaten the health and sustainability of marine ecosystems, including those already under protection. You will also be introduced to some of the other ecosystem-based management approaches that are being implemented to help revive precious resources within these ecosystems.

Optional Extensions

UNESCO - Islands and Protected Areas of the Gulf of California

Cabo Pulmo – Giving Optimism to Coral Reefs

Research Article Mangroves in the Gulf of California increase fishery yields

Industrial fishing in marine protected areas poses significant threats to endangered sharks and other species

The Downside of 'Paper Parks'

Momentum grows for ocean preserves. How well do they work?

A Path to Creating the First Generation of High Seas Protected Areas

Marine Biodiversity in Dangerous Decline, Finds New Report

U.S. National Marine Sanctuaries History Timeline

Across the world's seas, more refuges for predators