Geology topics

S. Jerrine Nichols

Publications and source records attributed to S. Jerrine Nichols.

21 records · Page 2Linked to original sources

USGS1988

Seasonal growth of the exotic submersed macrophyte Nitellopsis obtusa in the Detroit River of the Great Lakes

Seasonal growth and occurrence of an exotic submersed aquatic macrophyte, Nitellopsis obtusa , was monitored at the head of the Detroit River of the Great Lakes from June 1984 to April 1985. Nitellopsis obtusa first appeared in early July, increased in biomass from July to September, remained at relatively high biomass from September to late January, and decreased substantially as ice breakup began in mid-February. By March it had become senescent, lacking chlorophyll and disintegrating easily. Nitellopsis obtusa was therefore available as a source of food and shelter for benthic and juvenile fish populations in late fall and winter, when other macrophytes were absent.

Canadian Journal of Botany↗

USGS1986

Distribution and habitat of Nitellopsis obtuse (Characeae) in the Laurentian Great Lakes

Nitellopsis obtusa , a macroalga (Characeae) native to Europe and Asia, was found in U.S. waters of the St. Clair-Detroit River system in 1983, thus extending the range of this taxon into the Laurentian Great Lakes about 850 km from the St. Lawrence River where it was first discovered in North America in 1978. Its occurrence only in water frequented by commercial shipping vessels suggests that it is distributed via this mechanism. In the St. Clair-Detroit River system, N. obtusa was collected with a Ponar grab at four locations, and with a grapnel at one additional location. It was the ninth most frequently found macrophyte and it was most abundant at Belle Isle in the Detroit River, where the mean dry-weight biomass in Ponar samples was 0 g m -2 in June, 37 g m -2 in August, and 32 g m −2 in September. Maximum biomass of this taxon in one Ponar grab at this location was 289 g m -2 in September. The alga occurred primarily in water of relatively low current velocity (11.3 cm s −1 ) and in association with Vallisneria americana, Myriophyllum spicatum, Potamogeton richardsonii, Najas flexilis , and Elodea canadensis .

Hydrobiologia↗

USGS1986

Benthic community of the Savannah River below a peaking hydropower station

The Savannah River below Hartwell Dam, on the South Carolina-Georgia border, contains at least 206 benthic invertebrate taxa, even though this tailwater undergoes substantial daily fluctuations in water flow, temperature, and dissolved oxygen. Oligochaetes, chironomids, and amphipods dominate the community immediately below the dam. Farther downstream, larger organisms (i.e., Ephemeroptera, Trichoptera, etc.) dominate the benthic community. The high diversity of this system is primarily attributed to the intensive effort we expended to identify invertebrates to species level. We conclude that tailwaters associated with peaking hydropower stations may in fact have the diverse community assemblages found in natural streams and that this has not been recognized by other investigators because the bulk of the fauna is made up of small forms that are easily overlooked. Comparisons of tailwater fauna communities with those in control areas should be limited to rivers of similar size.

Journal of the Elisha Mitchell Scientific Society↗