Research Identifies 'Hot Spots' Of Ocean Productivity

Research by Oregon State University scientists showed that near CapePerpetua, an ocean area of high primary productivity, barnaclepopulations produced five times as many offspring as those living nearCape Foulweather, a region of lower productivity. In controlledexperiments, the scientists found an even larger effect of nearshoreocean conditions - Cape Perpetua barnacles produced more than 120 timesas many babies as those in the Cape Foulweather area.

The study highlights the importance of including information onecological processes when designing reserves and other types of marineprotected areas, the scientists said. It is one of the first studies tolink reproductive variation with key ecological processes on a scalethat's relevant to management and conservation. The findings werepublished today in a professional journal, Proceedings of the NationalAcademy of Sciences.

"This study demonstrates that not all ocean places are equivalent,and that some populations are more likely than others to contribute tofuture generations," said Heather Leslie, a marine ecologist at OSU."This could serve as a model for how to link information onbiodiversity patterns with underlying ecological processes."

Variability in ocean currents and bottom topography, as well asbiological interactions, all can contribute to differences in theproductivity of marine ecosystems. Biodiversity protection andenhancement of nearby fisheries are among the goals of marine reserves,the researchers said, and an important aspect of siting effectivereserves would be understanding how the productivity of key populationsvary.

"Not all ocean areas are the same, and the likelihood of fulfillingthe objectives of reserves and other area-based management effortswould increase if we understand the ecological processes responsiblefor biodiversity patterns," Leslie said.

Integrating this information is particularly important, Leslie said,given the forecasts of changes in ocean currents and other biologicaland physical processes due to climate change.

Barnacles, Leslie said, have a life history similar to many othermarine species and could serve as a useful model of how variation inocean productivity affects higher trophic levels, all the way up thefood chain to major fisheries. Barnacles also play an important role inrocky shore dynamics, serve as prey for many predators, provide habitatfor other organisms and help some species such as mussels getestablished.

Using these barnacles as an indicator of larger processes, thisresearch demonstrated that variation in primary productivity and otherkey processes can translate into significantly greater or lesserreproductive potential. The barnacles at Cape Perpetua produced manymore offspring, both individually and per unit area. The higherproductivity, researchers say, is probably linked to the widercontinental shelf and more complex bottom topography near Cape Perpetua.

"Scientists have traditionally assumed that ocean conditions werefairly uniform on the scale of tens or hundreds of miles," Leslie said."We know now that isn't the case. There are very significantdifferences in the productivity of marine populations in areas even afew miles apart."

This research is part of the work being done through PISCO, thePartnership for Interdisciplinary Study of Coastal Oceans, and wassupported by grants from the David and Lucile Packard Foundation, theAndrew W. Mellon Foundation, and the National Science Foundation. PISCOfocuses on understanding the nearshore ecosystems of the West Coast ofthe United States through interdisciplinary research, student trainingand outreach programs.