Coaches: Cassandra Otero
Tuesday, April 19th
2:00 PM

Origin of Atmospheric Mercury Deposition to Pacific Northwest Alpine Lakes

Will Erickson
Ruth Thurkill

Science 100

2:00 PM - 2:15 PM

Pacific Northwest lakes mainly receive their atmospheric weather patterns from Asia and as a result also receive many pollutants in the form of wet and dry deposition. Alpine lake water samples from the Big Horn Crags in the Frank Church Wilderness Area (Idaho), Olympic National Park (Washington), City of Seattle Watershed Reservoirs, and the Eagle Cap Wilderness area (Oregon) were analyzed for isotopic mercury. Water samples from these lakes are currently being isotopically analyzed using an inductively coupled plasma-mass spectrometry-quadrupole (ICP-MS-Q ). Frank Church, Eagle Cap, Seattle watershed, and Olympia National Park samples show mercury concentrations in the low parts-per-trillion (ppt) and parts-per-quadrillion range (ppq). Initial analysis shows that mercury concentrations decrease as air fronts go inland.Samples will later be analyzed for 198Hg, 199Hg, 201Hg, 202Hg that will fingerprint the origin of mercury. Sources of mercury include United States and China coal pollution, and volcanic emission.

2:15 PM

Is Ocean Acidification Melting Sea Stars? The Effect of Lowered pH and Wasting Disease on Nearshore Asteroid Health

Nina Finley

Science 100

2:15 PM - 12:00 AM

Sea Star Wasting Disease (SSWD), the largest wildlife epizootic ever recorded, has killed millions of sea stars since June 2013. Evidence points to a viral infectious agent, Sea Star-Associated Densovirus, and multiple environmental factors are probably involved. This study evaluated the effect of ocean acidification (OA) on the progression of SSWD in four native Puget Sound species. Thirty-five individuals were maintained in ambient pH of Elliot Bay (pH = 7.80 to 8.00) or lowered pH predicted for 2100 (pH = 7.40 to 7.60). Daily visual grading and computed tomography (CT) were used to quantify the effects of OA on sea star health and ossicle density. Our results show that OA conditions accelerate SSWD in mottled sea stars during the first 25 days of exposure. Preliminary analysis indicates that OA decreases ossicle density, suggesting a trade-off between skeletal maintenance and immune function serves to amplify SSWD in OA conditions.

2:30 PM

Recruitment as a Tool for Coral Reef Conservation

John Debuysser

Science 100

2:30 PM - 2:45 PM

Coral reefs are refugia of biodiversity of the ocean, but these critical habitats are in decline worldwide due to changing environment parameters and human impact. Coral recruitment, the settlement of coral larvae on substrate, is an excellent indicator of coral reproductive success and a key process for recovery and resiliency of reef-building corals. However, recruitment is a sensitive process that is influenced by a number of factors including coral stock health, ocean currents, algal competition, pollution and site connectivity. These factors produce large variations in recruitment across time and location. Pinpointing the factors critical to recruitment success in the Caribbean by establishing patterns of recruit density and examining correlations with environmental parameters are essential to protecting the health and productivity of valuable coral reef ecosystems. This work furthers the understanding of this phenomenon by describing coral recruitment patterns in coral reefs of the Turks and Caicos Islands.