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Long-Term (1927-1978) Changes In The Phytoplankton Community Of Lake Michigan At Chicago, R. Baybutt, Joseph Makarewicz
Long-Term (1927-1978) Changes In The Phytoplankton Community Of Lake Michigan At Chicago, R. Baybutt, Joseph Makarewicz
Joseph C Makarewicz
Fifty-one years of phytoplankton data from the South District Water Intake of the Chicago Water Filtration Plant were analyzed to determine changes in the phytoplankton community related to the eutrophication of Lake Michigan. From 1930 to 1940, a net biomass (~100 mg C/m3) indicative of oligotrophic-mesotrophic conditions were implied by the net algal biomass. By 1961 net algal biomass was ~600 mg C/m3-a biomass indicative of a eutrophic lake. Much of the biomass increase is due to Tabellaria, Stephanodiscus tenuis and S. binderanus. Since the early 1970's, there has been a consistent general decrease in algal biomass to levels associated …
Phytoplankton And Zooplankton: In Lakes Erie, Lake Huron And Lake Michigan: 1984, Joseph Makarewicz
Phytoplankton And Zooplankton: In Lakes Erie, Lake Huron And Lake Michigan: 1984, Joseph Makarewicz
Joseph C Makarewicz
With the acknowledgement that biological monitoring was fundamental to charting ecosystem health (Great Lakes Water Quality Agreement 1978), EPA's program was developed for Lakes Erie, Huron and Michigan to: 1) monitor seasonal patterns, ranges of abundance and, in general, structure of the phytoplankton and zooplankton communities; 2) relate the biological components to variations in the physical, nutrient and biological environment; and 3) assess the annual variance to allow better long-term assessments of trophic structure and state. Several offshore stations (9-11) on several cruises (9-11) during the spring, summer and autumn of 1984 and winter of 1985 were sampled. By examining …
Trophic Interactions: Changes In Phytoplankton Community Structure Coinciding With Alewife Introduction (Alosa Pseudoharengus), Joseph Makarewicz
Trophic Interactions: Changes In Phytoplankton Community Structure Coinciding With Alewife Introduction (Alosa Pseudoharengus), Joseph Makarewicz
Joseph C Makarewicz
Conesus Lake is a eutrophic lake (MILLS 1975) and the most western of the Finger Lakes of New York State, USA. Abundance of a top level predator, the walleye (Stizostedion vitreum vitreum), decreased from a high of 12,000 individuals in 1966 to 9,614 individuals in 1975 to 1,850 individuals by 1985 in Conesus Lake (ABRAHAM 1989). Coincidental with the decline of the walleye in Conesus Lake was the proliferation of an obligate planktivore, Alosa pseudoharengus (ABRAHAM 1988). During the late 1970s (probably 1978 or 79), the alewife was accidentally introduced and became established in the lake. The pre-alewife zooplankton community …
Multivariate Analysis Of The Lake Michigan Phytoplankton Community At Chicago, R. Baybutt, Joseph Makarewicz
Multivariate Analysis Of The Lake Michigan Phytoplankton Community At Chicago, R. Baybutt, Joseph Makarewicz
Joseph C Makarewicz
Ordination techniques were used to analyze phytoplankton and water chemistry data collected between 1927 and 1978 from Lake Michigan at Chicago. Ordination analysis summarized the phytoplankton data and illustrated the progression from oligotrophy to eutrophy and the subsequent reversal of cultural eutrophication after 1970 in the nearshore waters of Lake Michigan at Chicago. The analysis highlighted a significant correlation between blue-green algal biomass and Na+ concentration. The increase in mean annual Na+ concentration in Lake Michigan at Chicago and the experimental evidence implying a Na+ requirement for blue-green algae suggested that the increase in blue-greens, although influenced by P enrichment …