Internship Opportunities
Pacific Coastal Ecology Branch (PCEB) has sponsored internships, temporarily employed, or hosted student guest investigators at the high school, undergraduate, and graduate student level. Sponsored interships have included the National Network for Environmental Management Studies (NNEMS) and STAR fellowships, primarily available to graduate students. Most of the undergraduates working at the EPA laboratory have done so as temporary employees in the summer, typically involved in supporting research of two or more EPA scientists. Other undergraduates have been sponsored through minority student internships or hosted as guest investigators as they pursued independent projects. Examples of projects are listed below:

Effects of desiccation and abrasion on seagrass (Zostera marina) growth. A field study was conducted to determine whether exposure at low tide (desiccation) or abrasion by attached green macroalgae (Chaetomorpha sp.) limit the upper intertidal distribution of the seagrass, Zostera marina. Results were that abrasion by this macroalga did not affect short-term growth of the seagrass, but desiccation damage was associated with reduced seagrass growth (blade length) and therefore may be an important limiting factor. Investigator: Katie Alayan. Mentor: Dr. Bruce Boese (boese.bruce@epa.gov).

Tidal exposure duration effects on seagrass (Zostera marina) leaf growth rate. Laboratory and field studies were conducted to investigate how tidal exposure and the slope of the substrate affect growth of seagrass. The investigators found that plants at low bathymetric intertidal elevation had longer blades and higher per-shoot biomass than plants at higher elevations, and that plants on shallow slopes had longer blades than plants on steep slopes. These findings contribute to the characterization of the growth characteristics within seagrass populations and to an understanding of the factors that regulate the distribution and abundance of seagrasses within PNW estuaries. Investigators: Alexis Loretz and Kyle Matthews. Mentor: Dr. Bruce Boese (boese.bruce@epa.gov).

Effect of reduced salinity on growth of green macroalgae. Laboratory and field experiments were conducted to examine whether reduced salinity associated with fall rains contribute to the seasonal break-up of extensive mats of green macroalgae common to many PNW estuaries. Results suggested that reduced salinity (ca. <15 psu) reduced the growth and biomass of green macroalgae and thus may be one of the factors causing the seasonal breakup of the mats. Investigator: Sam Chan. Mentor: Dr. Jim Kaldy (kaldy.jim@epa.gov).

Effects of burrowing shrimp size and population density on burrow morphology & geometry. A field study was conducted to determine whether population density affected the shape and packing arrangement of burrows of the intertidal mud shrimp (Upogebia pugettensis). Changes in the morphology and geometry of the burrows affects the depth and lateral extent to which sediments are irrigated with oxygenated seawater, and thus affects geochemical cycling of organic matter and nutrients between the seafloor and water column. Geometric measurements were taken from plastic resin casts of mud shrimp burrows made in low- and high-density shrimp populations on Yaquina bay tideflats. Results indicated that, for a given sized animal, burrows in high density populations penetrated deeper into the sediment but otherwise had more variable shape than burrows in low-density populations, probably reflecting consequences of crowding (i.e., interspecific interactions prevent construction of "classic" shaped burrows). Investigator: Reed Ozretich. Mentor: Dr. Ted DeWitt (dewitt.ted@epa.gov).

Impact of burrowing shrimp (Upogebia pugettensis) on estuarine phytoplankton abundance. Field and laboratory experiments were conducted to measure whether populations of a burrowing shrimp, common to PNW estuaries, have a significant impact on the abundance of estuarine phytoplankton. Experiments examined particle size preference and filtration rate (particle clearance rate) as a function of shrimp size and population density, and compared filter feeding behavior of this shrimp with two estuarine bivalves. A "population-filtration" model, developed from the experimental data and shrimp population distribution data, suggests that Upogebia populations in the lower part of Yaquina bay estuary are capable of filtering the entire body of overlying water between one and two times daily. Investigator: Blaine Griffen. Mentor: Dr. Ted DeWitt (dewitt.ted@epa.gov).

Consumption rates and prey preferences of the green crab, Carcinus maenas (Linneaus), for four bivalve prey species in Pacific northwest estuaries. Laboratory experiments were conducted to examine predation behavior of the European green crab, which is a recent invader to PNW estuaries and a voracious predator of bivalves. Results suggest that green crabs pose a serious new threat to PNW bivalve populations, and that Yaquina oysters are at greater risk of green crab predation than bent-nosed clams and Manila clams, and Cryptomya clams are at greater risk than bent-nosed clams. Investigator: Kelly Palacios. Mentor: Dr. Steven Ferraro (ferraro.steven@epa.gov).