Oregon State University
Oregon State University (http://oregonstate.edu/) participates in all of the core PISCO research and takes a lead role in some aspects of the program. Our research focuses primarily on the Oregon coast, with some of our studies occuring in Washington and California also. PISCO OSU is committed to sharing our research results not only via traditional scientific publications, but also through direct interactions with policymakers, resource managers and the general public. Our scientists regularly share information with these groups and provide scientific information to inform decision-making.
The Research Program
Nearshore Oceanography
PISCO research at OSU begins in the nearshore ocean, with an array of oceanographic moorings. This year, we deployed 13 moorings along the central coast of Oregon; deployments in past years have included as many as 26 moorings, extending from Cascade Head in the north to Cape Blanco in the south. Our research has found that the nearshore Pacific Ocean off Oregon is characterized by intermittent, weak summer upwelling with periods of relaxation. The PISCO OSU nearshore oceanography program also includes several cruises each month during the summer of 2003 that monitor physical and biological conditions in the water. This research follows up on PISCO studies that helped to uncover a zone of low-oxygen water that killed marine fish and invertebrates along the central coast of Oregon in 2002. Scientists have rarely, if ever, recorded hypoxic conditions along the Oregon coast. PISCO research is helping to unravel the cause of this event, which likely resulted from a combination of increased phytoplankton blooms and unusual circulation patterns that brough oxygen-poor water nearer to shore than usual, and predict possible recurrences.
Because we deploy and service our moorings by boat, a research vessel is crucial to our work. PISCO, with additional support from Oregon State University's Research Office and College of Oceanic and Atmospheric Sciences (COAS), funded a new boat for use by the OSU community. The R/V Elekha is a 54-foot vessel that is specially designed for oceanographic research and is ideal for studying the nearshore ocean.
Additional data gathering activities supplement the information we collect with nearshore moorings. For example, PISCO OSU collaborates with researchers at COAS to determine surface current patterns across different areas using Acoustic Doppler Current Profilers (ADCPs) and coastal radar (CODAR). We also use a towed "Acrobat" device to quantify physical oceanographic patterns in the nearshore region. To facilitate these and other collaborations, PISCO co-sponsors the annual Pacific Northwest Oceanographic Research Meeting (PNORM).
Shoreline Research
Recruitment, Community Structure, and Ecological Interactions: As part of PISCO's investigations of recruitment patterns and the effects of nearshore oceanographic conditions, we intensively sample individuals that have settled in rocky intertidal areas at approximately 15 sites in the region from Cape Mendocino, California, to Cape Meares, Oregon. We have documented that periodic reversals in ocean currents are usually associated with barnacle recruitment events on the shore. Recruitment of invertebrates then drops sharply, not gradually, at Cape Blanco.
PISCO OSU also has expanded the consortium's surveys of shallow rocky reefs and kelp forests into Oregon. We sample subtidal communities at four locations on the central and south coast of Oregon. During these surveys, scientists measure recruitment of young fishes and characterize the community by quantifying fishes, invertebrates, and algae. These measures link patterns of population replenishment and community structure with nearshore larval supply and oceanographic conditions.
PISCO OSU leads the consortium's research into the diversity and structure of biological communities. Our quantitative assessments are unprecedented in scale, ranging from Cape Flattery, Washington, to La Jolla, California. Each year, we assess community diversity and structure at nearly 50 intertidal sites using a methodology developed by former Postdoctoral Researcher Carl Schoch. As part of our research into community diversity, we created a web-based taxonomic reference to rocky intertidal invertebrates and algae. The reference is used by PISCO as a training tool to ensure consistency in identification.
During the community diversity surveys, we observe a greater number of species in the north than in the south. However, this pattern is not evident at all sites, indicating that local factors also affect species diversity. We also are uncovering links between ecological responses and physical attributes of the nearshore environment. At large scales (e.g., 10-100 km), oceanographic processes such as nutrient upwelling, water temperature and patterns of water movement influence community structure by controlling food supply and the release and distribution of larvae. However, at small scales (e.g., 10-100 m), the hydrodynamics of the nearshore, substrate size, elevation on the shore, and biological interactions become more important in determining local distributions of coastal species. Our research suggests that physically similar habitats support similar biological communities, even when separated by long stretches of heterogeneous shoreline.
We are taking the lead to study the intensity of key species interactions such as predation and grazing, which influence patterns of coastal communities. We estimate predation intensity by measuring the rate of disappearance of mussels transplanted to areas with and without predators (i.e., sea stars and whelks) at six sites. We are refining a second experiment that studies herbivory. Herbivore effects of limpets and chitons are quantified by excluding grazers from experimental plots with copper-based paint, a deterrent to these organisms. PISCO's study of species interactions provides insight into how these ecological processes affect community patterns.
Physiology and Growth: OSU leads PISCO's research into the condition of individual organisms. We determine the growth potential of mussels by measuring the RNA:DNA ratio of adductor tissue. We also quantify algal condition by measuring the ratio of carbon to nitrogen (C:N). These methods help us to determine how an organism's survival is influenced by the environment at distinct points in time. Physiological studies evaluate the effects of environmental factors, such as temperature and desiccation, on the well-being of organisms. To measure exposure-related stress, our scientists analyze heat-shock proteins. These studies enable us to understand organisms' tolerance ranges and their responses to changes in the environment.
PISCO OSU, along with UCSB and UCSC, studies growth rates of invertebrates and fishes in rocky intertidal and shallow subtidal areas. To examine oceanographic conditions, we monitor concentrations of phytoplankton and nutrients in nearshore waters. PISCO OSU collects water samples at 30 sites four times each summer, and at 15 sites twice during winter months. Since 2000, we have sampled chlorophyll concentrations in nearshore waters on moorings at 3 to 6 locations. We determine growth rates of mussels and barnacles at nine sites either by transplanting marked individuals (i.e., mussels) to an experimental plot or by allowing recruitment (i.e., acorn barnacles) in a competition-free environment. Our surveys show that sites along the southern Oregon Coast typically have higher concentrations of chlorophyll-a than those along the central coast. Chlorophyll-a concentrations correlate with concentrations of phytoplankton, a food source for filter feeders. We have found that sites with high chlorophyll-a concentrations typically have higher growth rates of mussels and barnacles