Meeting Abstracts chaetognatha and cnidaria Return to Thuesen Homepage


Pacific Estuarine Research Society Annual Meeting in Portland, Oregon in May, 2002

Ecophysiology of gelatinous zooplankton in estuarine hypoxia, Erik V. Thuesen

Physiological adaptations and behavioral responses of gelatinous zooplankton to estuarine hypoxia, Gabrielle Kirouac, Heather Wiedenhoft, Patrica L. Brommer, Ladd D. Rutherford, Jr., and Erik V. Thuesen

Heat shock proteins induced by oxygen stress in the jellyfish Aurelia labiata, Jessica A. Archer, Anna M. Brownstein, Magdalena A. Gutowska, Amanda L. Robbins, Andrew Brabban and Erik V. Thuesen


Partners in Science National Conference in San Diego, California in January, 2002

The effect of hypoxia on oxygen consumption, survivalbility and behavior of gelatinous zooplankton in the southern Puget Sound

Kurt Garrison, CHOICE High School, Shelton, Washington & Erik Thuesen, Evergreen State College


American Society of Limnology and Oceanography in Santa Fe, New Mexico in Feb, 2001

OXYGEN REGULATION AND SURVIVAL IN HYPOXIA BY ESTUARINE GELATINOUS ZOOPLANKTON

Thuesen, E.V. & Ladd D. Rutherford Jr.

Gelatinous zooplankton are known to thrive in estuaries that experience episodic hypoxia, and their ability to tolerate low oxygen conditions may have significant effects on pelagic food web structure. We have examined the oxygen regulatory abilities of several species of gelatinous zooplankton in southern Puget Sound, including ctenophores, hydromedusae, scyphomedusae and siphonophores in order to understand the mechanisms whereby these organisms can withstand low oxygen conditions. Some species can oxyregulate to below 15% oxygen saturation. When transferred from high-oxygen water to water depleted in oxygen, ctenophores and medusae release oxygen into a closed chamber. Enough oxygen is stored to allow these organisms to live aerobically in total anoxia for over an hour. This novel oxygen storage mechanism may be important for many gelatinous zooplankters that migrate vertically in and out of low oxygen environments.

 

THE EFFECT OF HYPOXIA ON OXYGEN CONSUMPTION AND SURVIVABILITY OF AURELIA LABIATA AND AEQUOREA VICTORIA IN SOUTHERN PUGET SOUND.

P.L. Brommer, J.C. Winet, S. Garcia & E.V. Thuesen

Estuarine gelatinous zooplankton are known to vertically migrate through areas of low oxygen, giving them a potential advantage over their zooplankton prey. Hypoxia in parts of Puget Sound is increasing due to the negative impacts of human population growth. We have examined the oxygen regulatory characteristics and ability to survive anoxia of the scyphomedusa Aurelia labiata and the hydromedusa Aequorea victoria in southern Puget Sound in order to estimate the impacts of low oxygen on these important zooplankters. Mean respirations rates for A. labiata and A. victoria were 0.18 and 0.31 Ámoles O2 g-1h-1, respectively. Measured critical oxygen partial pressures (Pc) indicate that A. labiata and A. victoria are able to regulate oxygen consumption despite diminishing oxygen concentration. Critical oxygen partial pressures for A. labiata and A. victoria were, 14.17 and 24.63 ▒7.14 mmHg, respectively. Aurelia labiata was observed to survive in anoxic conditions for ~10 hours and A. victoria for ~ 5 hours.


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