White Abalone (Haliotis Sorenseni) - Andrew Cisterman

Andrew Cisterman - BIO 227 

WHITE ABALONE

~Haliotis Sorenseni~ 

Description And Ecology of Organism:

The white abalone (halitosis sorenseni) is a species of large sea snail, a marine gastropod mollusk in the Haliotide family. White abalone on average grow to 7 inches but have been known to grow up to 10 inches and on average weigh about 1.7 pounds. They primarily range from Central California to Central Baja Mexico. Of the 8 species of California Abalones, the white abalone is the deepest dwelling, living at depths of 80 to 200 feet. They are commonly found in rock and boulder habitats that are interspersed with sand channels. The white abalone is an herbivore, feeding mainly on several algae and micro algae species. They live about 35 to 40 years and become sexually mature between years 4 and 6.

Listing Date and Type of Listing:

The white abalone was listed as an endangered species throughout its range under the Endangered Species Act (ESA) effective June, 2001. The listing came after completing a comprehensive status review of the species. The status review found an urgent need for human intervention in the recovery of the white abalone because it unlikely that the species will recover on its own.

Geographic and Population Changes:

The population of white abalone has not shifted much geographically and can still be found in the same historical locations. Currently they are reported being most abundant between 100 and 200 foot depths. Historically, they occurred along the mainland coast and at offshore islands and banks at depths as shallow as 15 feet.

Surveys conducted in Southern California since the time of the status review confirm the status review’s conclusion that at least a 99% reduction in white abalone density has occurred between the 1970s and today. 

Main Threats to Continued Existence:

Low Reproduction Rates: Female abalone reproduce by releasing as many as 10 million eggs at at time, but unless they come in contact with sperm from spawning males, the cannot be fertilized. The dramatic increase in their population density has resulted in abalone finding themselves far from potential mates making reproduction unlikely or impossible.

Commercial Catch Weight

Overfishing: Of all abalone species, the white abalone is notorious for its tender and flavorful meat. A commercial abalone fishery opened in California in the early 1970s, peaked in the mid-1970s, and closed in the 1980s. Even with fishing regulations in place to reduce the number of abalone caught, the fishery greatly decreased the abalone populations and has had long-term effects on their recovery.

Recovery Plan:

1. Assess and monitor subpopulations of white abalone in the wild in cooperation with the state of California, other federal agencies, private organizations and the Mexican government.

2. Identify and characterize existing and potential white abalone habitat through acoustic remote sensing technology.

3. Protect white abalone populations and their habitat in the wild. 

4. Continue and expand a captive propagation and enhancement program for white abalone in California. 

5. Develop enforcement, public outreach and education plans. 

6. Secure financial support for white abalone recovery.

The population goals of this recovery plan are to achieve:

- Population density of 2000 per hectare for 75 percent of the geographic localities

- Maintain a total of 380,000 animals in the wild.


What Can You Do:

Help enforce the law! It is illegal to fish for, catch, or keep any species of abalone in California except recreational take of red abalone north of San Francisco during designated periods with proper permits and tags.




Link showing data collection and abalone breeding in captivity:

https://www.youtube.com/watch?v=jux70JAGzmc







Sources:
http://www.nmfs.noaa.gov/pr/pdfs/recovery/whiteabalone.pdf

https://www.fisheries.noaa.gov/species/white-abalone