Otsego Lake Macrobenthos Communities between 1968 and 1993: Indicators of Decreasing Water Quality

Abstract

Otsego Lake is a diictic lake that fills a depression formed by the overdeepening of the headwaters of the Susquehanna River in New York. During summer stratification, the hypolimnetic waters become oxygen depleted, which has potential impacts on the cold-water fishery and has caused changes in the distribution of profundal macroinvertebrates. Trends in water quality parameters attest to the stresses of eutrophication, and artificial alterations in water levels have negatively impacted eulittoral macrobenthos. Eulittoral species richness has decreased 27.7% h m 1968-88 to 1989-93. Ephemeroptera-Plecoptera-Trichoptera species richness has decreased 56.1%. Mollusca richness 52.9%. Invertebrate biomass at all depths remained stable between 1935 and 1969, but has increased since then. In 1968 mollusks dominated the eulittoral environment, arthropods were preponderant at 4-30 m in depth, and oligochaetes claimed the deepest waters. The entire littoral benthic community is now dominated by mollusks, and oligochaetes occupy substrates at middle profundal depths at the expense of the fingernail clams and the Chironomidae.

Malacocoenoses of large lowland dam reservoirs of The Vistula River basin and selected aspects of their function

“…Similar changes were observed in lakes (e.g. HARMAN & FORNEY 1970, MORGAN 1970, STAÑCZY-KOWSKA et al 1983, HARMAN 1997, KANGUR et al 1998, PIECZYÑSKA et al 1999, GONG & XIE 2001. In the 1990s, some reservoirs started to show symptoms of a change of the above tendency, which was associated with an improvement in their water quality (e.g.…”

Long-term changes and spatial variability of mollusc communities in a lowland reservoir (Zegrzyński Reservoir, C Poland)

“…A limiting effect of eutrophication on the mollusc species diversity was observed by various authors (e.g. HARMAN & FORNEY 1970, PIP 1987, MOUTHON 1996, HARMAN 1997, PIECZYÑSKA et al 1999. The number of mollusc species found in bottom samples from the Zegrzyñski Reservoir in 1997-1999 has not changed significantly since 1995 and thus it may indicate stabilisation of the malacofauna composition in the 90s at the level clearly lower than that observed 10 years earlier.…”

“…Since that period the increase in abundance of D. polymorpha has been so intense that the proportion of V. viviparus in the malacocenoses has decreased de-144 Ewa Jurkiewicz-Karnkowska Table 4. Changes in the frequency of selected (most common in 1986-1987) mollusc species between 1986-1987, 1995and 1997a -littoral zone, b -central zone Taxa 1980a -littoral zone, b -central zone Taxa -1981a -littoral zone, b -central zone Taxa 1986a -littoral zone, b -central zone Taxa -1987a -littoral zone, b -central zone Taxa 1995 & LUFEROV 1966, GIZIÑSKI & WOLNOMIEJSKI 1982, BORODICH & LYAKHOV 1983, GIZIÑSKI et al 1989, PEROVA & SHCHERBINA 1998. The mean abundance of molluscs has decreased many times in the mouth section of the Bug river and several times in the mid parts of the reservoir (transects IV and V); a trend resulting from a considerable reduction in abundance of many small bivalves (Sphaeriidae) and prosobranchs (L. naticoides, T. fluviatilis, V. piscinalis, V. naticina).…”

A Test of the Species–people Correlation for Stream Macro‐invertebrates in European Countries

“…Ephemeroptera, Plecoptera, and Trichoptera (EPT) are taxa widely used as bio-indicators of freshwater biotic integrity (Hoiland et al 1994, Harman 1997, Wright and Smock 2001, Malmqvist 2002, Ode et al 2005, Lecerf et al 2006. Freshwater ecosystems are currently experiencing alarming declines in biodiversity and have been assessed to be just as threatened as tropical rain forests (Ricciardi andRasmussen 1999, Suski andCooke 2007).…”