After the recent discovery of a destructive mussel in the Sacramento-San Joaquin River Delta, some experts say California officials have failed to effectively enforce laws designed to protect waterways from invaders carried in ships’ ballast water. A state law enacted 20 years ago has required California officials to inspect 25% of incoming ships and sample their ballast water before it’s discharged into waterways. But the tests didn’t begin until two years ago — after standards for conducting them were finally set — and testing remains rare. State officials have sampled the ballast water of only 16 vessels out of the roughly 3,000 likely to have emptied their tanks nearshore. Experts say stronger regulations are needed, as well as better enforcement.

Related article:

• ABC 10 (Sacramento): Lake Berryessa enacts 30-day boat quarantine to prevent spread of invasive mussels