The exact date when the season will close will be determined soon, California Department of Fish and Game spokesman Ian Taniguchi said.
Three of the commission's five members approved the emergency closure at a meeting this morning in Redding, Taniguchi said. Commissioners Daniel Richards and Richard Rogers were absent from the meeting.
The abalone season typically opens April 1, closes during the month of July and resumes Aug. 1 through Nov. 30.
Taniguchi said this is the beginning of the slowest period of the abalone harvesting season. Last year, only 11 percent of the season's abalone take took place in October and November, Taniguchi said.
The Department of Fish and Game issues an annual average of 35,000 reporting cards statewide that are required of abalone fishermen, Taniguchi said.
The abalone season will continue in Marin, Mendocino, Humboldt and Del Norte counties, Taniguchi said.
Dead and dying red abalone and sea stars were reported along coves on the Sonoma County coast starting Aug. 27.
Department of Fish and Game biologists said the deaths coincided with a local red tide phytoplankton bloom and calm ocean conditions. Such a bloom can result in the suffocation of marine life, and can create biotoxins that are harmful to shellfish and the humans who eat them.
Abalone fishermen who have become ill are advised to immediately contact a physician and report their symptoms to their local health department.
However, the exact reasons for the abalone die-off are not known. There have been invertebrate die-offs along the Northern California coast in the past when similar weather and bloom conditions existed, but not previously to this extent, Fish and Game officials said.