The focus of the research is the nutritive processes of small hydromedusae. The large medusae that are so familiar in coastal waters because they are visible to the naked eye are important plankton predators that can strongly affect the numbers of zooplankton (microscopic marine animals) as well as fish eggs and larvae. The very small medusae that are the focus of the study are far more abundant than their larger relatives. In spite of their status as the largest and most diverse group of gelatinous zooplankton in the sea, the feeding ecology of small jellyfish is virtually unknown.
During the course of this project Gifford and colleagues will study small hydromedusae in Narragansett Bay, Rhode Island, to quantify the impact of the feeding ecology of the hydromedusae on the plankton community and to quantify when and what they are feeding on. It has been determined that hydromedusae are omnivorous, feeding on both very small zooplankton (microzooplankton) and phytoplankton (microscopic marine plants). Preliminary studies indicate that the small jellyfish are likely to represent a completely unexpected source of mortality on the spring phytoplankton bloom in northern coastal waters.
"This research will lead to new understanding of community feeding rates, prey selection patterns and the underlying feeding mechanisms that have led to the success and evolutionary longevity of the most diverse group of medusae," said Gifford. "The study will also provide evolutionary ecologists with a greater understanding of the biomechanical factors that have influenced the evolution of small hydromedusan body form and function as well as the behavior and body form of its prey."
Each of the collaborating institutions will involve students and teachers in every aspect of the research.
The URI Graduate School of Oceanography is one of the country's largest marine science education programs, and one of the world's foremost marine research institutions. Founded in 1961 in Narragansett, RI, GSO serves a community of scientists who are researching the causes of and solutions to such problems as acid rain, harmful algal blooms, global warming, air and water pollution, oil spills, overfishing, and coastal erosion. GSO is home to the Coastal Institute, the Coastal Resources Center, Rhode Island Sea Grant, the Institute for Archaeological Oceanography, and the National Sea Grant Library.