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Marine Protected Areas and the Value of Resilient Coasts

Increasing the resilience of our coasts by protecting resources can serve as a buffer against climate-related, anomalous, and unprecedented disturbance events

Photo by Katie Davis Koehn

With the loss of nearly half of all marine life in the last 40 years, we are in a crucial time period for the preservation of ocean-dwelling species and building ecological resilience along our coasts. The industrialization of global fisheries has led to depletion of fish stocks and has degraded marine ecosystems. Reduced biodiversity in these communities makes them more susceptible to disturbance events such as disease outbreaks, invasive species, and climatic episodes.

Here in the Santa Barbara Channel, resource harvesting, oil extraction, and marine shipping contribute to diminished resilience of the coastal zone. Marine protected areas (MPAs) are powerful tools for reversing these adverse effects and have been designated in the region for the purpose of increasing resilience, restoring biodiversity, enhancing recreational opportunities, and preserving both economic and cultural resources for future generations.

With the passage of the Marine Life Protection Act (MLPA) in 1999, the State of California established 120 underwater refuges, which grew the percentage of protected California coastal waters from 2.7% to 16.1%. In the Santa Barbara Channel region, 17 marine reserves with varying levels of restrictions combine to protect the unique marine ecosystem of the Southern California Bight.

How do MPAs increase resilience?

MPAs minimize human disturbance within their boundaries, which protects the functionality of the greater ecosystem and, by proxy, the economically and culturally important resources in our waters. Many of our local reserves are “no-take,” meaning that no fishing or harvesting is allowed. No-take reserves have been shown to boost fish biomass by 300-700%, which then results in “spillover” effects that increase catches for nearby fisheries. Recreational divers get to enjoy these impacts first-hand, often seeing large lobsters, abundant kelp forests, and the large diversity of fishes that seek refuge in these protected places.

By increasing biodiversity, MPAs also have the indirect effect of restoring the structure and complexity of the ecosystem by stabilizing food webs. This then boosts the resilience of the entire system. Resilience looks different in every ecosystem, but often includes high levels of both diversity and abundance of native species.

With larger populations of kelp, invertebrates, and fishes, MPAs become increasingly resilient to environmental disturbances such as storms, El Nino-related sea surface temperature fluctuations, and mass mortality events. While these types of disturbances are not new phenomena, global climate change is expected to increase their frequency and severity. MPAs won’t prevent the effects of climate change, but they may provide a buffer against extreme responses to unpredictable events. Because of this relationship, it is crucial that we support the development and persistence of MPAs to increase coastal resilience and protect our resources from the exacerbated effects of climate change.

Disturbance and Resilience in Coastal California

From 2013-2016, a large swath of warm water nicknamed “The Blob” resulted in elevated ocean temperatures that created ecological disorder. This anomaly was associated with several disturbance events in California, one of which was a massive epidemic of sea star wasting disease that causes their bodies to rapidly dissolve. The outbreak is both ongoing and unprecedented, and resulted in a 99% decline in the ecologically critical ochre sea star. Decreasing the abundance of a keystone species so drastically can cause long-term, cascading effects throughout the food web, the potential severity of which are unknown as declines have never been recorded at this scale.

Research on marine disease indicates that changing environmental conditions associated with climate change are leading to increased incidence of disease outbreaks in marine ecosystems. However, multiple studies have demonstrated that disease is less prevalent, and communities are more resilient to disturbances, in MPAs where critical environmental parameters are maintained.

Another relevant example of a potential growing threat under climate change is that of invasive species. Invasions cause economic and management costs to the US of approximately $120 billion per year, threaten biodiversity, and are difficult to prevent, control, or reverse. More marine invasions are expected to occur with intensifying marine shipping traffic and climate-change related temperature increases. Recent research finds that older, well-protected MPAs are more resistant to these invasions. Robust kelp forest ecosystems, like those in the Santa Barbara Channel, have been found to be resilient to ocean warming. This underscores the importance of conservation of these resources. Safeguarding against invasives and disease could minimize future economic losses and generate ecological resilience to climate-related threats.

MPAs Are One Piece of a Large Puzzle

These examples of environmental stressors are far from the only potential agents of ecosystem change. MPAs reduce human impacts on marine ecosystems and are drivers of resilience and resistance to threats, including invasives. Overall, an integrated and multi-faceted approach is required to protect our coasts, as there is not a singular problem preventing resilience or one solution to creating it. Further, as we strive for resilient coasts, we must bear in mind that there is no prescription for immunity from environmental disturbance.

The California MPA Collaborative Network , formed in 2013 and co-chaired by the EDC, emphasizes stakeholder-driven management that allows a range of voices to be heard in the process of building resilience along our coasts. Join us in participating in community-based management of our MPAs! Your actions today can contribute to creating abundant and resilient coasts to be enjoyed by future generations.

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Molly Williams is an intern with EDC’s Marine Conservation Program and is a master’s student studying coastal and marine resources management at the UCSB Bren School of Environmental Science and Management (class of 2019).

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