Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Winter rains make SF Bay less salty, knocking back some invaders

Leave a Comment

December 7, 2017  Smithsonian Read full ScienceDaily article here

For many Californians, last year’s wet winter triggered a case of whiplash. After five years of drought, rain from October 2016 to February 2017 broke more than a century of records. In San Francisco Bay, biologists discovered a hidden side effect: All that freshwater rain can turn the tables on some of the bay’s invasive species….

…During dry years, when bay waters remained salty, one invader dominated above all others: the invasive tunicate Ciona robusta. A translucent, vase-shaped filter feeder from Asia, Ciona has invaded five continents, including North America’s West Coast. It has a reputation for crowding out other species, thanks to its rapid growth, and similar Ciona species have thrown a wrench into shellfish aquaculture.

But when the wetter winters of 2006 and 2011 hit, Ciona and other solitary tunicates like it were unable to cope with the massive influxes of freshwater. In their place, mat-like colonial tunicates and encrusting bryozoans took over….

Andrew L. Chang, Christopher W. Brown, Jeffrey A. Crooks, Gregory M. Ruiz. Dry and wet periods drive rapid shifts in community assembly in an estuarine ecosystem. Global Change Biology, 2017; DOI: 10.1111/gcb.13972

View all articles

Comments are closed