“The very air here is miraculous, and outlines of reality change with the moment.” ~John Steinbeck and Edward F. Ricketts, Sea of Cortez (1941)
Although we may still think of the Gulf of California as the “World’s Aquarium,” it was added to the List of World Heritage in Danger in July 2019. A considerable amount of research there in the last 20 years has revealed some concerning changes. For example, after the strong El Niño of 2009-10, Humboldt squid in the Gulf started to reproduce at an unusually small size and young age (0.1 kg and 6 months) compared to the size and age (>20 kg and 2 years) they previously had reached in this region between the mid 1990’s and 2009. During this time, the central Gulf of California supported a thriving commercial squid fishery, in which squid were individually caught on hand lines using 12 inch “jigs” that look like spiky metal brushes. But small Humboldt squid are logistically impossible to catch in commercial quantity with the local jigging methods, and after 2010 the commercial fishery went from about 60,000 tons per year (3rd or 4th largest fishery in Mexico) to zero by 2015. Today, squid remain small, the fishery that once employed thousands of people is gone, and squid-eating sperm whales (known locally as cachalote) have largely abandoned the Gulf.
During this time of biological change, the Gulf of California experienced a period of unusually warm sea surface (and subsurface) conditions, a reduction in seasonal wind-driven upwelling, and decreased chlorophyll-a concentrations (reflecting phytoplankton productivity) compared to the previous decade (2000-2010). Such large-scale environmental changes would be expected to modify productivity of this tropical-subtropical ecosystem and affect many types of marine organisms in addition to calamar and cachalote. Unfortunately, this appears to have been the case.
To gain a broader perspective, an online workshop was organized by colleagues in Mexico, Carlos Robinson (ICML-UNAM, Mexico City), Jaime Gómez Gutiérrez and Sergio Hernández-Trujillo (both from CICIMAR, La Paz) for a diverse group of scientific experts from Mexico, USA, Canada, Peru, Spain, and France to share and integrate relevant information from multiple disciplines. The Resilience of the Gulf of California Workshop was held on Nov 18-20, 2020, with 258 participants presenting 65 papers in sessions devoted to Biodiversity and Productivity, Fisheries and Conservation, Meteorology and Oceanography, Modelling, Ocean Circulation, Plankton-Benthos-Nekton ecology, and Ocean Technology. Presenters described fascinating observations on subjects ranging from harmful algal blooms and zooplankton to the ecology of larger organisms like squid, coastal and oceanic fish, seabirds, and marine mammals – primarily in the context of the prolonged warming event. Other talks focused on physical details of the oceanographic and meteorological changes themselves. Many changes in the Gulf of California were identified and discussed, with most changes being unfavorable based on the perspective of what we consider a healthy Gulf to be. Papers based on work presented will be published in a special issue of the journal Progress in Oceanography, “Resilience of the Gulf of California to Climatic Change.”
Although the Resilience workshop was successful in bringing participants together to identify both problems and new collaborations, it must be seen as an important step in a long future process to take action to adapt and mitigate negative impacts of a warming climate on the biota and human population inhabiting in the Gulf of California (nearly 11 million people). Climate change will not only raise average sea water temperature over time, it will also alter seasonal, interannual and interdecadal climatic processes, including El Niño and more recently observed multi-year marine heat waves in the Pacific northwest and Gulf of Alaska. Such processes are the real drivers of marine ecosystems and fisheries, and the case of Humboldt squid illustrates how radical – and unexpected — impacts can be for marine creatures as well as humans.
Going forward, we need explicit action to avoid both the traps of long-established human impacts on ecosystems, including destructive fishing practices, pollution, and indiscriminate coastal development, and the more recently recognized threats of climate change. As a start we must continue international efforts to synthesize available data, collect and incorporate new data sets of relevance, disseminate this information to a broad audience, and translate findings into policy.
The Western Flyer Foundation is committed to assisting with this critical work, with the Western Flyer making trips into the Gulf every other year to collaborate in local research programs and to connect with local communities in education and outreach efforts. Signs of cracks may be appearing in the “World’s Aquarium,” but there is still much there to be admired, studied, and preserved. It is up to us to keep pushing on through the troubled seas.
-William Gilly, Ph.D
Board Member and Chief Scientist with the Western Flyer Foundation