Southern California's Perfect Beaches Are Killing Wildlife

(Bloomberg) -- Southern California is known for its pristinely maintained beaches. But those perfect ribbons of sand are causing problems for the surrounding ecosystems.

Grooming and filling, primarily intended to beautify the sand for human recreation, is altering the biodiversity of beach ecosystems, according to new research from UC Santa Barbara's Marine Science Institute. Heavily-trafficked urban beaches had about half as many native insects and crustaceans than reference beaches, the study found. The removal of wrack, like kelp and seaweed can also be detrimental to local species that rely on it for food and shelter, according to lead author Nick Schooler.

The human desire to warp nature for leisure has seriously altered much of California’s southern coastline. An astonishing 67% of the state’s coast could be completely eroded by the end of the century, according to 2017 research. The process is only intensified by human activity, Schooler said, and could worsen as sea levels rise.

These impacts could contribute to regional losses of biodiversity, degrade ecological stability, resilience and function of these widespread coastal ecosystems, said Schooler. 

The research calls for an enhancement and conservation of the unique biodiversity and function of remaining beach ecosystems and more ecologically sensitive management approaches to find a greater balance between urban beaches socioeconomic and irreplaceable ecological functions.

“It’s the most intense disturbance of the habitat, more than any agricultural or farming practice that we could think of and it removes this key subsidy that supports life on beaches,” Schooler said.

Another, more episodic, but major factor that contributed to the decline in species was the size, sorting and coarseness of non-native sediments used to fill urban beaches, a process known as beach filling or nourishment, the research found. The practice “dramatically altered the natural sediment,” said Schooler. Even the vehicles used to dump the sand are detrimental, crushing and killing animal life on the beach.

The urban beaches showed homogenization of species across all landscapes and regions, while the undisturbed reference beaches were found to support high biodiversity, even when near urban centers. Not a single one of the 73 species tracked by the researchers flourished on the urban beaches. 

The researchers tracked 16 beaches in four areas (Santa Barbara, Santa Monica, San Pedro and Oceanside) spread along 186 miles of coastline between 2009 and 2015. At least one urban and one reference beach were located in each area.  

The work is important, Schooler said, because “we are losing our beaches in southern California.”

To contact the editor responsible for this story: Joshua Petri at jpetri4@bloomberg.net

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