Ecophysiology of gelatinous
organisms in hypoxia
Erik V. Thuesen, Ph.D.
The Evergreen State College
Wednesday, October 10, 2001
3:00 p.m.–Pacific Forum
Several species of ecologically important gelatinous zooplankton in
southern Puget Sound and Chesapeake Bay have been examined in order to
estimate the effects of low oxygen. The study focused on the oxygen
regulatory abilities of the zooplankton and their ability to tolerate
anoxic conditions. The study included ctenophores, scyphomedusae,
hyromedusae, and siphonophores.
The mean oxygen consumption rate, minimum partial pressure to which the
organism can regulate oxygen consumption (Pc), and the ability of each
species to withstand anoxia have been measured. Results show that several
species can oxyregulate at less than 10% oxygen saturation and survive
complete anoxia for several hours. The oxygen concentration in the gel has
been measured, and it appears that the gel facilitates oxygen diffusion.
These results indicate that gelatinous organisms are better at tolerating
poor oxgyen conditions than many of their pelagic competitors and prey.
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