CORVALLIS, Ore. - A study of barnacles on the central Oregon Coast has revealed significant "hot spots" of ocean productivity where marine life has much greater reproductive potential - information that could be a key to the successful siting of marine reserves.
Research by Oregon State University scientists showed that near Cape Perpetua, an ocean area of high primary productivity, barnacle populations produced five times as many offspring as those living near Cape Foulweather, a region of lower productivity. In controlled experiments, the scientists found an even larger effect of nearshore ocean conditions - Cape Perpetua barnacles produced more than 120 times as many babies as those in the Cape Foulweather area.
The study highlights the importance of including information on ecological processes when designing reserves and other types of marine protected areas, the scientists said. It is one of the first studies to link reproductive variation with key ecological processes on a scale that's relevant to management and conservation. The findings were published today in a professional journal, Proceedings of the National Academy of Sciences.
"This study demonstrates that not all ocean places are equivalent, and that some populations are more likely than others to contribute to future generations," said Heather Leslie, a marine ecologist at OSU. "This could serve as a model for how to link information on biodiversity patterns with underlying ecological processes."
Variability in ocean currents and bottom topography, as well as biological interactions, all can contribute to differences in the productivity of marine ecosystems. Biodiversity protection and enhancement of nearby fisheries are among the goals of marine reserves, the researchers said, and an important aspect of siting effective reserves would be understanding how the productivity of key populations vary.
"Not all ocean areas are the same, and the likelihood of fulfilling the objectives of reserves and other area-based management efforts would increase if we understand the ecological processes responsible for biodiversity patterns," Leslie said.
Integrating this information is particularly important, Leslie said, given the forecasts of changes in ocean currents and other biological and physical processes due to climate change.
Barnacles, Leslie said, have a life history similar to many other marine species and could serve as a useful model of how variation in ocean productivity affects higher trophic levels, all the way up the food chain to major fisheries. Barnacles also play an important role in rocky shore dynamics, serve as prey for many predators, provide habitat for other organisms and help some species such as mussels get established.
Using these barnacles as an indicator of larger processes, this research demonstrated that variation in primary productivity and other key processes can translate into significantly greater or lesser reproductive potential. The barnacles at Cape Perpetua produced many more offspring, both individually and per unit area. The higher productivity, researchers say, is probably linked to the wider continental shelf and more complex bottom topography near Cape Perpetua.
"Scientists have traditionally assumed that ocean conditions were fairly uniform on the scale of tens or hundreds of miles," Leslie said. "We know now that isn't the case. There are very significant differences in the productivity of marine populations in areas even a few miles apart."
This research is part of the work being done through PISCO, the Partnership for Interdisciplinary Study of Coastal Oceans, and was supported by grants from the David and Lucile Packard Foundation, the Andrew W. Mellon Foundation, and the National Science Foundation. PISCO focuses on understanding the nearshore ecosystems of the West Coast of the United States through interdisciplinary research, student training and outreach programs.