July 14 () –
The rise in ocean temperatures is sweeping the seas, breaking records and creating problematic conditions for marine life, with effects that last for months or years.
All over the world, you are “marine heat waves” have led to mass species mortality and displacement events, economic declines, and habitat loss. New research reveals that even areas of the ocean protected from fishing remain vulnerable to these extreme events fueled by climate change.
A study published in Global Change Biology, led by UC Santa Barbara researchers, found that while California’s network of marine protected areas (MPAs) provide many social and ecological benefits, they are not resistant to the effects of warming of the oceans.
MPAs are locations in the ocean where human activities, such as fishing, are restricted to conserve and protect marine ecosystems, habitats, species, and cultural resources.
The study, part of a 10-year review of California’s MPA network conducted at UCSB’s National Center for Ecological Analysis and Synthesis (NCEAS), found that marine heatwaves affect ecological communities regardless of whether they are protected. within the AMPs.
“MPAs in California and around the world have many benefits, such as increased fish abundance, biomass, and diversity,” he said. it’s a statement Joshua Smith, who led the study while a postdoctoral researcher at NCEAS. “But they were never designed to buffer the impacts of climate change or marine heat waves.”
Smith and co-authors from around the world were part of an NCEAS working group formed to synthesize decades of long-term ecological monitoring data from California’s diverse ocean habitats.
The group, co-led by Jenn Caselle, a researcher at the UCSB Institute of Marine Sciences, and Kerry Nickols, a professor at Cal State University Northridge who now works with the nonprofit organization Ocean Visions, aimed to provide actionable scientific results to formulators. California Policy. and managers of natural resources, as part of a statewide Decadal Assessment of the MPA network.
Their analyzes covered the largest marine heat wave on record, which swept across the Pacific Ocean toward California between 2014 and 2016. The monstrous marine heat wave formed from an environmental double whammy: an unusual warming of the ocean dubbed “The Blob.” , followed by a major El Niño event that prolonged sweltering sea temperatures. The marine heat wave swept the West Coast from Alaska to Baja, leaving a trail of disrupted food webs, collapsed fisheries, and displaced marine life populations, among other consequences.
As MPA managers around the world face increasing weather shocks, The extent to which MPAs can cushion the worst of these events has become an important question. The working group scientists asked how ecological communities in California’s protected areas fared after such a severe and prolonged heat wave: would the communities change, and if so, how? Would they recover when the marine heat wave subsided? Could marine protected areas protect sensitive populations or facilitate recovery?
To find answers to their questions, they synthesized more than a decade of data collected from 13 no-take MPAs located in a variety of ecosystems along the Central Coast: rocky intertidal zones, kelp forests, deep and shallow rocky reefs. . The team analyzed populations of fish, invertebrates, and marine algae inside and outside these areas, using data from before, during, and after the heat wave.
They also focused on two of these habitats, intertidal rocky forest and kelp, in 28 MPAs across the state network to assess whether these locations promoted a particular form of climate resilience: maintain both the population and the community structure.
“We use no-take MPAs as a type of comparison to see if protected ecological communities coped better with the marine heat wave than the places where the fishing took placesaid Smith, now an ocean conservation researcher at the Monterey Bay Aquarium.
The results are somewhat sobering, though not entirely unexpected. “MPAs did not facilitate resistance or recovery between habitats or communities,” Caselle said. “In the face of this unprecedented marine heat wave, communities changed dramatically in most habitats. But, with one exception, the changes occurred in a similar way both inside and outside MPAs. What was new about this study was that we saw results similar in many different habitats and taxonomic groups, from deep water to shallow reefs and from fish to algae.”
The implication of these findings, according to Smith, is that every part of the ocean is threatened by climate change. “AMPs are effective in many of the ways they were designed, but our findings suggest that MPAs alone are not enough to buffer the effects of climate change.”
