Abalones Under Threat

The International Union for Conservation of Nature (IUCN) has since 1964 published the Red List of Threatened Species. The list is a great tool, informing about biodiversity and conservation, and providing data for policy change and protection of natural resources. Invertebrates such as mollusks have traditionally been neglected and only relatively recently have found their way into the Red List. The abalone family Haliotidae is one of the few families of mollusks with all known species covered in the list. Of the 54 species included (here in order of increasing concern), nine are listed as “data deficient,” three as “near threatened”, seven as “vulnerable,” six as “endangered,” seven as “critically endangered.” None are listed as “extinct in the wild” or “extinct.”

Paua, Haliotis iris, is listed in the IUCN Red List as a species of least concern, but with unknown trends in population numbers.

The remainder are species of “least concern.” Not surprisingly, the group of seven “critically endangered” species (all registered as showing “decreasing population trends”) includes five commercially important species, the Red (Haliotis rufescens), Black (H. cracherodii), Green (H. fulgens), White (H. sorenseni), and Pink Abalone (H. corrugata). In a short article published in Tentacle (newsletter of the Mollusc Specialist Group of the Species Survival Commission, IUCN), Howard Peters, Laura Robers-Bennett, and Gina M. Ralph list and discuss* the threats to abalones Threats are led by overfishing, but also include viral diseases, ocean acidification, and climate change (reflected in the warming of ocean temperatures). The authors also discuss how captive breeding and aquaculture may help mitigate in part those concerning global trends.

*Read the Tentacle article on page 57, here.

The photo above shows yours truly holding a 3.5-year-old Red Abalone, Haliotis rufescens, grown in captivity. The photo was taken at Abulones Cultivados, the oldest abalone farm in Mexico, located in Ejido Erendira, Baja California Norte. At the time the photo was taken (August 2016), Abulones Cultivados was beginning to suffer, like many open-water marine aquaculture businesses around the world, the impacts of ocean acidification and sea surface temperature changes.