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

Beach grooming is the practice of mechanically removing debris, including trash, kelp wrack, shells and driftwood, from a beach.
Photographer: Nick Schooler

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....