Aquatic Sciences Meeting, Albuquerque 2001

SS21 Ultraviolet Radiation and the Aquatic Biota (Disciplinary Connections)

Date: Wednesday, February 14, 2001, Time: 12:00:00 PM

Location: Galisteo

Thorp, J, H, Clarkson University, Potsdam, NY, USA, thorp@clarkson.edu

Wehr, J, D, Fordham University, Armonk, NY, USA, wehr@fordham.edu

Morris, D, P, Lehigh University, Bethlehem, PA, USA, dpm2@lehigh.edu

Williamson, C, E, Lehigh University, Bethlehem, PA, USA, cew0@lehigh.edu

Casper, A, F, Clarkson University, Potsdam, NY, USA, casperaf@clarkson.edu

Perrone, A, A, Fordham University, Armonk, NY, USA, aperrone@murray.fordham.edu

PATTERNS IN ULTRAVIOLET RADIATION, DOC, AND PLANKTON IN THE UPPER ST. LAWRENCE RIVER

Characteristics of plankton (bacterioplankton, phytoplankton, zooplankton), water chemistry (nutrients, Chl-a, DOC, etc.), and absorption of ultraviolet light were evaluated in 3 regions of the St. Lawrence River from Lake Ontario to Massena, NY: (1) an upper, braided region within the Thousand Island area near Lake Ontario (3 segments); (2) a middle, constricted-channel region (2 segments); and (3) a lower, broad region known as Lake St. Lawrence (2 segments). Within each segment, we collected 3 sample replicates in August from each of 4 habitats: main channel (MC), main channel border (MCB), embayment (E), and embayment with tributary (ET). The average absorption coefficient for solar radiation at 320 nm (2.54 m-1 for the river as a whole) generally increased downstream in main channel habitats and was partially correlated with DOC levels (average = 4.1 mg.L-1). Absorption was influenced by habitat and decreased in the order ET>E>MCB>MC, whereas DOC followed the order MCB>ET>E>MC. Chl-a and the density and fecundity of microcrustaceans decreased downstream, while the importance of rotifers rose. Slack-water areas contained greater densities of plankton than higher velocity sites.

This Session Listing

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks