Ruth DiMaria - Marine & Estuarine Ecology
George Mason University, Virginia
Effects of Hypoxia on the Reproductive Viability of Fundulus heteroclitus
All aquatic organisms need oxygen to survive but their oxygen needs differ depending on many factors including the species, lifecycle stage, and time of year. Hypoxia, or low dissolved oxygen (DO), has significant effects upon fishes including: lower growth rates; altered distributions, behavior, and placement in food webs; and significant reductions in abundance, diversity, and harvest (Breitburg 2002). The seasonal size and duration of hypoxic and anoxic waters produced by anthropogenic nutrification appear to be increasing in coastal and estuarine ecosystems world wide (Diaz 2001).
Fundulus heteroclitus, mummichog, are hardy fish which can tolerate wide ranges in salinity and temperature. Because of this, F. heteroclitus are more likely to remain in low DO backwaters than fishes with lower tolerance levels. Advantages to remaining in low DO waters include relative protection from predators and access to food sources. However, F. heteroclitus populations subject themselves to less than favorable conditions which may affect their behavior, growth, and reproduction.
Funding provided by the Smithsonian Institution Women’s Committee