Phytoplankton Dynamics and Hypoxia in Lake Erie: A Hypothesis Concerning Benthic-pelagic Coupling in the Central Basin

Distribution of seston and nutrient concentrations in the eastern basin of Lake Erie pre- and post-dreissenid mussel invasion

“…Present and previous results give strong evidence that mussel grazing can lower chla concentrations in many natural settings, but chla can have a variable relationship to phytoplankton biomass (Conroy et al, 2005;Fitzpatrick et al, 2007; but see Carrick et al, 2005). Chla was not significantly correlated to phytoplankton wet biomass in the offshore of Lake Erie (Conroy et al, 2005).…”

“…They attributed the differences to changes in composition, size-structure, and photo-adaptive state of the phytoplankton community (Fitzpatrick et al, 2007). However, Carrick et al (2005) showed strong correlations between phytoplankton biomass (measured as C determined from cell counts) and chla (r 2 = 0.91) in the central basin of Lake Erie in 2002. Their 2002 central basin offshore summer chla concentrations (2.0 μg L −1 ; Carrick et al, 2005) were also comparable to our 2002 eastern basin offshore concentrations (1.8 μg L −1 ).…”

“…However, Carrick et al (2005) showed strong correlations between phytoplankton biomass (measured as C determined from cell counts) and chla (r 2 = 0.91) in the central basin of Lake Erie in 2002. Their 2002 central basin offshore summer chla concentrations (2.0 μg L −1 ; Carrick et al, 2005) were also comparable to our 2002 eastern basin offshore concentrations (1.8 μg L −1 ). Our north-shore survey data also indicated that chla concentrations in the nearshore were reflective of similar differences in phytoplankton biomass (Fig.…”

Burrowing mayfly (Ephemeroptera: Ephemeridae: Hexagenia spp.) bioturbation and bioirrigation: A source of internal phosphorus loading in Lake Erie

“…The sediments for Toot (2000) and our experiment were collected from the nearisland region of western Lake Erie; however, 6 years separated the collection dates. It would be likely that the organic content and phosphorus concentration of the sediments would be different possibly due to accumulation of organic material from Dreissena mussel biodeposits (Schloesser et al, 2005) and sedimentation of large algal blooms (Hansen and Blackburn, 1992;Carrick et al, 2005). Phosphorus concentrations of our sediment control were at least twice the amount of Toot (2000) control with out nymphs.…”

Assessing water quality in lake Naivasha

“…Around this period, some researchers described the lake as a muddy fish pond because of the reduced size and dissolved and suspended particulate matter which turned the colour of the water to brown (Njogu et al, 2011). In February 2010, a large fish kill occurred apparently due to high organic matter concentrations in the water column (including dead phytoplankton) that cause high oxygen demands and may, in severe cases, lead to anoxic conditions that cause fish kills (Carrick et al, 2005). The muddy condition began to improve in 2011 following a considerable increase in rainfall which resulted in higher lake water levels compared to the previous two years.…”