02605nas a2200241 4500008004100000245011200041210006900153490000700222520179100229653002202020653002102042653002502063653003402088653003202122653002602154100001902180700002102199700002802220700001602248700002202264700002002286856005702306 2004 eng d00aWater Quality Impacts and Indicators of Metabolic Activity of the Zebra Mussel Invasion of the Seneca River0 aWater Quality Impacts and Indicators of Metabolic Activity of th0 v403 a

ABSTRACT: The conspicuous shifts in summertime values of common measures of water qualify that have persisted for 10 years (1993 to 2002) in the Seneca River, New York, as a result of the zebra mussel invasion are documented. Resolution of patterns in time and space is supported by water quality monitoring that extends back to the late 1970s. Patterns are evaluated to describe the stability of impacts and quantify metabolic activity of the invader. The water quality impacts that have persisted unabated for 10 years since the invasion are the most severe documented for a river in North America. Changes in summer median conditions since the invasion include: (1) a 16-fold decrease in chlorophyll concentration (Chi), (2) a 2.5-fold increase in Secchi disc transparency, (3) a 17-fold increase in soluble reactive phosphorus concentration, (4) a 3.7-fold increase in total ammonia concentration, (5) a greater than 25 percent decrease in dissolved oxygen (DO) concentration, and (6) a decrease in pH of 0.55 units. The strength of these signatures has been driven by anthropogenic influences that include upstream nutrient loading and morphometric modifications of the river, and the functioning of Cross Lake, through which the river flows. This hypereutrophic lake sustains dense zebra mussel populations and related water quality impacts in the river downstream of the lake outflow by acting as a source of veligers and suitable food for this bivalve. Evidence is presented that levels of metabolic activity of the zebra mussel in this river have been resource limited, manifested through increased consumption of Chl and DO with increased delivery of these constituents in the lake's outflow.

10aaquatic ecosystem10adissolved oxygen10aDreissena polymorpha10ametabolic activity indicators10awaste assimilative capacity10awater quality impacts1 aEffler, S., W.1 aMatthews, D., A.1 aBrooks-Matthews, C., A.1 aPerkins, M.1 aSiegfried, C., A.1 aHassett, J., M. uhttp://dx.doi.org/10.1111/j.1752-1688.2004.tb04456.x02131nas a2200229 4500008004100000245005900041210005900100300001200159490000700171520148600178653002601664653002101690653001801711653001801729100001901747700001901766700001801785700002201803700001601825700001901841856004101860 1996 eng d00aImpact of Zebra Mussel Invasion on River Water Quality0 aImpact of Zebra Mussel Invasion on River Water Quality a205-2140 v683 a

The biology of the zebra mussel is reviewed as it relates to water-quality problems in rivers. A relationship between population densities of the zebra mussel and their respiration demands for oxygen is developed, which can be used to support the analysis of the impact of zebra mussel infestation on the oxygen resources of streams and rivers. Dramatic changes in the water quality of the Seneca River, N.Y., a major tributary to Lake Ontario, have been brought about by zebra mussel infestation. These changes are documented from 3 years of monitoring data. The infestation converted the Seneca River from a turbid, phytoplankton-rich, nutrient-depleted system, with nearly saturated oxygen concentrations, to a river with high clarity, low-phytoplankton concentrations, enriched in dissolved nutrients, with greatly undersaturated oxygen concentrations. The degradation of oxygen resources was severe enough to cause violations of New York State standards for daily minimum and daily average concentrations for a number of days in the late summer of 1993. The associated loss in the waste assimilative capacity of the river is confounding waste discharge management and planning efforts in the river basin. This form of degradation is expected for other systems as the zebra mussel infestation spreads. The impact is expected to be greatest in rivers and streams with high concentrations of phytoplankton, large areas of rock substrate, and limited reaeration capacity.

10aassimilative capacity10adissolved oxygen10awater quality10aZebra mussels1 aEffler, S., W.1 aBrooks, C., M.1 aWhitehead, K.1 aSiegfried, C., A.1 aWalrath, L.1 aCanale, R., P. uhttp://www.jstor.org/stable/25044708