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| http://eol.org/pages/620425/overview |
Abalone is a type of edible mollusk found along the coastal waters of every continent except the Atlantic coast of South America, the Caribbean, and the east coast of the United States. Abalone adhere tightly to rocky surfaces by taking advantage of the high surface area of their broad muscular foot. Abalone belong to the genus Haliotis, of which contains about 100 species [7]. The majority of these species live in cold waters. Also, abalone in general are very sensitive to thermal changes. They show little tendency to adapt to chronically altered thermal environments and respond poorly to acute thermal shock [2].
How do they reproduce?
Abalones reach maturity at a relatively small size. Their fecundity or their ability to produce new offspring increases with their size. However, high demand for abalone meat has removed them (especially large individuals) at a rate that could drive wild populations to extinction.
Furthermore, abalone are free-spawning/broadcast-spawning invertebrates meaning they release both female and male gametes into the external environment for fertilization. Therefore the population density is highly correlated to the per capita population growth. This relationship is a phenomenon known as the Allee effect. Free-spawners have to rely on water movement and close proximity to one another for successful fertilization. According to this phenomenon, overfishing of abalone to critically low numbers of individuals could potentially and very easily wipe out an entire population [4].
What do they eat?
Abalone are herbivores that consume algae.
Why are they declining in numbers?
Abalone are considered seafood delicacies. Abalone meat is considered a food delicacy in many parts of the world. The meat can be consumed raw or cooked. Their shells are also prized because of the thick inner layer of the shell composed of nacre. Nacre is highly iridescent, which gives it a range of beautiful colors that are attractive to humans. Abalone shells are used as decorative objects and used as a source of mother-of-pearl for jewelry and other decorative pieces [7].
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| http://www.aroundhawaii.com/lifestyle/food/2010-05-sushi-surprise-at-zenshu.html |
Some species like Haliotis cracherodii are considered critically endangered on the IUCN Red List of Threatened Species. Declining abalone populations is due to overfishing and rising temperatures and acidification of oceans from anthropogenic carbon dioxide. Rising temperatures and acidification will be the main focus of this website. Other reasons for decline also include predation by sea otters on the western US coast, mortality by disease, competition with sea urchins and other species, illegal harvesting, and loss of habitat.
