Tougher boat inspections are coming to two San Luis Obispo County lakes. Zebra and quagga mussels are invasive shellfish. They can damage a lake’s ecosystem and water equipment. According to the Tribune, Neither Lopez Lake or Santa Margarita Lake are infected with the shellfish — and the county wants to keep it that way. Starting Nov. 1, all boats entering the two lakes will be inspected for both mussels.