Editing Geoduck (section)

==Biology==
Native to the [[British Columbia Coast|west coast]] of [[Canada]] and the northwest coast of the [[United States]] (primarily [[Washington (state)|Washington]] and [[British Columbia]]), these [[Marine (ocean)|marine]] [[bivalve]] [[mollusk]]s are the largest burrowing clams in the world, weighing in at an average of {{convert|1+1/2|lb|kg|1|order=flip}} at maturity, but [[Biological specimen|specimen]]s weighing over {{convert|15|lb|kg|round=0.5|order=flip}} and as much as {{convert|2|m|ftin|sp=us}} in length are not unheard of.{{Citation needed|date=August 2008}}

A related species, ''[[Panopea zelandica]]'', is found in New Zealand and has been harvested commercially since 1989. The largest quantities have come from Golden Bay in the South Island where {{convert|100|tonne|ST}} were harvested in one year. There is a growing concern over the increase of parasites in the Puget Sound population of geoduck. Whether these [[microsporidium]]-like parasitic species were introduced by commercial farming is being studied by Sea Grant. Research to date does indicate their presence.<ref>{{cite web|url=https://wsg.washington.edu/wordpress/wp-content/uploads/publications/Geoduck-Final-Report-Dec-2013.pdf|title=Geoduck Aquaculture Research Program|website=wsg.washington.edu|publisher=Geoduck Aquaculture Research Program, Washington Sea Grant|access-date=18 April 2014}}</ref>

The oldest recorded specimen was 179 years old, but individuals usually live up to 140 years.<ref name=Orensanz/> A geoduck sucks water containing [[plankton]] down through its long siphon, filters this for food and ejects its refuse out through a separate hole in the siphon. Adult geoducks have few natural [[predator]]s, which may also contribute to their longevity. In [[Alaska]], [[sea otter]]s and [[Squaliformes|dogfish]] have proved capable of dislodging geoducks; [[starfish]] also attack and feed on the exposed geoduck siphon.

Geoducks are broadcast spawners. A female geoduck produces about 5 [[1,000,000,000|billion]] eggs in her century-long lifespan. However, due to a low rate of recruitment and a high rate of mortality for geoduck eggs, larvae, and post-settled juveniles, populations are slow to rebound.<ref>{{cite thesis|last=Willner|first=Georgina B.|title=The Potential Impacts of the Commercial Geoduck (''Panope generosa'') Hydraulic Harvest Method on Organisms in the Sediment and at the Water-Sediment Interface in Puget Sound|degree=Master|publisher=The Evergreen State College|location=Olympia, Washington|date=June 2006|url=https://protectourshoreline.org/articles/ThesisGeoduckHarvestImpacts.pdf|access-date=1 January 2023}}</ref> In the Puget Sound, studies indicate that the recovery time for a harvested tract is 39 years.<ref>{{cite report|last1=Palazzi|first1=David C.|first2=Lynn|last2=Goodwin|first3=Alex|last3=Bradbury|first4=Bob|last4=Sizemore|last5=Washington (state)|editor-first1=Leigh|editor-last1=Espy|editor-first2=Susan|editor-last2=Sturges|editor-first3=Candis|editor-last3=Ladenburg|editor-first4=Blanch|editor-last4=Sabottke|date=23 May 2001|title=Final Supplemental Environmental Impact Statement: State of Washington Commercial Geoduck Fishery|location=Olympia WA|publisher=State of Washington Department of Natural Resources: Department of Fish and Wildlife|url=https://www.dnr.wa.gov/publications/aqr_geo_lowres2001_final_seis.pdf|access-date=1 January 2023|page=5}}</ref>

[[Biomass (ecology)|Biomass]] densities in Southeast Alaska are estimated by divers, then inflated by twenty percent to account for geoducks not visible at the time of survey.<ref name=Rumble2012>{{cite journal |author1=Rumble, JM |author2=Hebert, KP |author3=Siddon, CE |title=Estimating Geoduck Harvest Rate and Show Factors in Southeast Alaska |journal=In: Steller D, Lobel L, Eds. Diving for Science 2012. Proceedings of the American Academy of Underwater Sciences 31st Symposium. |year=2012 |url=http://archive.rubicon-foundation.org/10279 |archive-url=https://archive.today/20130929031850/http://archive.rubicon-foundation.org/10279 |url-status=usurped|archive-date=29 September 2013 |access-date=29 September 2013 }}</ref> This estimate is used to predict the two percent allowed for commercial harvesting.<ref name=Rumble2012/>