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Full-Text Articles in Life Sciences

Alteration Of The Food Web Along The Antarctic Peninsula In Response To A Regional Warming Trend, Mark A. Moline, Herve Claustre, Thomas K. Frazer, Oscar Schofield, Maria Vernet Nov 2004

Alteration Of The Food Web Along The Antarctic Peninsula In Response To A Regional Warming Trend, Mark A. Moline, Herve Claustre, Thomas K. Frazer, Oscar Schofield, Maria Vernet

Biological Sciences

In the nearshore coastal waters along the Antarctic Peninsula, a recurrent shift in phytoplankton community structure, from diatoms to cryptophytes, has been documented. The shift was observed in consecutive years (1991–1996) during the austral summer and was correlated in time and space with glacial melt-water runoff and reduced surface water salinities. Elevated temperatures along the Peninsula will increase the extent of coastal melt-water zones and the seasonal prevalence of cryptophytes. This is significant because a change from diatoms to cryptophytes represents a marked shift in the size distribution of the phytoplankton community, which will, in turn, impact the zooplankton assemblage. …


Analysis Of Phytoplankton Nutrient Limitation In Farmington Bay And The Great Salt Lake, Wayne A. Wurtsbaugh, Amy M. Marcarelli Jun 2004

Analysis Of Phytoplankton Nutrient Limitation In Farmington Bay And The Great Salt Lake, Wayne A. Wurtsbaugh, Amy M. Marcarelli

Watershed Sciences Faculty Publications

The Great Salt Lake is bordered to the south and east by a growing metropolitan area that contributes high nutrients to Farmington Bay. This large bay is eutrophic, and there is concern that continued increases in effluents from the Salt Lake City area could extend to impact the much larger, and currently less productive, Gilbert Bay. This study focused on determining how nutrient supplies might limit, and therefore control, algal populations in Farmington Bay and Gilbert Bay at different salinities. We tested both short and long-term responses of algal growth using laboratory nutrient addition bioassays in the summer and fall …


Impacts Of A Recurrent Resuspension Event And Variable Phytoplankton Community Composition On Remote Sensing Reflectance, Trisha Bergmann, Gary Fahnenstiel, Steven Lohrenz, David Millie, Oscar Schofield May 2004

Impacts Of A Recurrent Resuspension Event And Variable Phytoplankton Community Composition On Remote Sensing Reflectance, Trisha Bergmann, Gary Fahnenstiel, Steven Lohrenz, David Millie, Oscar Schofield

Faculty Publications

In order to characterize the impact of turbidity plumes on optical and biological dynamics, a suite of environmental parameters were measured in southern Lake Michigan during the springtime recurrent sediment plume. In-water measurements of inherent optical properties (IOPs) were entered into the Hydrolight 4.2 radiative transfer model and the output was compared with measured apparent optical properties (AOPs) across a wide range of optical conditions. Hydrolight output and measured underwater light fields were then used to clarify the effects of the sediment plume on primary production, phytoplankton community composition, and nearshore remote sensing ocean color algorithms. Our results show that …


Phytoplankton Composition Within The Tidal Freshwater-Oligohaline Regions Of The Rappahannock And Pamunkey Rivers In Virginia, Harold G. Marshall, Lubomira Burchardt Jan 2004

Phytoplankton Composition Within The Tidal Freshwater-Oligohaline Regions Of The Rappahannock And Pamunkey Rivers In Virginia, Harold G. Marshall, Lubomira Burchardt

Biological Sciences Faculty Publications

The Rappahannock River is a major river system across north central Virginia prior to entering the Chesapeake Bay. In contrast, the Pamunkey River is smaller in size and joins the Mattoponi River to form the York River, which flows parallel to the Rappahannock before it also flows into Chesapeake Bay. A unique mixing area for both flora and environmental conditions exists in the tidal freshwater-oligohaline region of both rivers. This is a dynamic mixing section where freshwater and estuarine species are subject to the interaction of river flow and daily tidal rhythms. The phytoplankton composition in this region of the …


Relevant Scales In Zooplankton Ecology: Distribution, Feeding, And Reproduction Of The Copepod Acartia Hudsonica In Response To Thin Layers Of The Diatom Skeletonema Costatum, Alexander B. Bochdansky, Stephen M. Bollens Jan 2004

Relevant Scales In Zooplankton Ecology: Distribution, Feeding, And Reproduction Of The Copepod Acartia Hudsonica In Response To Thin Layers Of The Diatom Skeletonema Costatum, Alexander B. Bochdansky, Stephen M. Bollens

OES Faculty Publications

We investigated the interaction of the copepod Acartia hudsonica in relation to thin layers of the diatom Skeletonema costatum. Thin layers have recently received much attention, since they are common and persistent features in the water column, often overlooked by traditional sampling methods. Their frequent abundance in coastal oceans and the high biomass associated with them has led to the assumption that they are important grazing sites of calanoid copepods. We employed 2-m tall tower tanks that allowed us to simulate thin layers. Three variables representative of three time scales were considered: the distribution of copepods in the tanks …