Reduced chlorophyll to phosphorus ratios in nearshore Great Lakes waters coincide with the establishment of dreissenid mussels

1999 ◽  
Vol 56 (1) ◽  
pp. 153-161 ◽  
Author(s):  
K H Nicholls ◽  
G J Hopkins ◽  
S J Standke

The establishment of zebra and quagga mussels (Dreissena spp.) in the Great Lakes has coincided with dramatic decreases in chlorophyll a to total phosphorus (Chl/TP) ratios in nearshore waters of Lake Erie, western Lake Ontario, and the Detroit River, but not in Lake Superior, southern Lake Huron, central and eastern Lake Ontario, or the upper St. Lawrence River. May-October average Chl/TP ratios in samples collected weekly (1976-1995) from five Lake Erie municipal water supply intakes were two to six times higher during the pre-Dreissena time period than during the post-Dreissena period. The pre-Dreissena logarithmically transformed Chl and TP data (May-October averages at all Great Lakes sampling locations) were highly correlated, with 75% of the log-transformed Chl variance explained by log-transformed TP. The post-Dreissena regression of May-October average Chl on TP was statistically significant, but only 14% of the variance in the Chl data could be explained by TP. We suggest that this has important implications for Great Lakes basin P management because changes in lake water TP resulting from further changes in TP loading will (post-Dreissena) have far less impact on Great Lakes phytoplankton growth potential than during pre-Dreissena times.

1995 ◽  
Vol 73 (2) ◽  
pp. 400-403 ◽  
Author(s):  
Adrian P. Spidle ◽  
Edward L. Mills ◽  
Bernie May

The coexistence of two dreissenids, the quagga mussel (Dreissena bugensis) and the zebra mussel (D. polymorpha), in a new environment raises the possibility of natural hybridization and possible introgression. Animals of both species were collected in areas where they occur sympatrically (25–39% were quagga mussels) and screened at two protein-coding loci believed to differentiate between the two species. The occurrence of alleles diagnostic for both species in an individual would demonstrate hybridization between the species. No hybrid individuals were observed in a survey of 750 animals from four sites in Lake Ontario and one site in Lake Erie. Successful hybridization between these two genetically disparate species seems unlikely in the Great Lakes.


1996 ◽  
Vol 31 (2) ◽  
pp. 411-432 ◽  
Author(s):  
Michael E. Comba ◽  
Janice L. Metcalfe-Smith ◽  
Klaus L.E. Kaiser

Abstract Zebra mussels were collected from 24 sites in Lake Erie, Lake Ontario and the St. Lawrence River between 1990 and 1992. Composite samples of whole mussels (15 sites) or soft tissues (9 sites) were analyzed for residues of organochlo-rine pesticides and PCBs to evaluate zebra mussels as biomonitors for organic contaminants. Mussels from most sites contained measurable quantities of most of the analytes. Mean concentrations were (in ng/g, whole mussel dry weight basis) 154 ΣPCB, 8.4 ΣDDT, 3.5 Σchlordane, 3.4 Σaldrin, 1.4 ΣBHC, 1.0 Σendosulfan, 0.80 mirex and 0.40 Σchlorobenzene. Concentrations varied greatly between sites, i.e., from 22 to 497 ng/g for ΣPCB and from 0.08 to 11.6 ng/g for ΣBHC, an indication that mussels are sensitive to different levels of contamination. Levels of ΣPCB and Σendosulfan were highest in mussels from the St. Lawrence River, whereas mirex was highest in those from Lake Ontario. Overall, mussels from Lake Erie were the least contaminated. These observations agree well with the spatial contaminant trends shown by other biomoni-toring programs. PCB congener class profiles in zebra mussels are also typical for nearby industrial sources, e.g., mussels below an aluminum casting plant contained 55% di-, tri- and tetrachlorobiphenyls versus 31% in those upstream. We propose the use of zebra mussels as biomonitors of organic contamination in the Great Lakes.


2009 ◽  
Vol 43 (4) ◽  
pp. 915-934 ◽  
Author(s):  
David F. Millie ◽  
Gary L. Fahnenstiel ◽  
Julianne Dyble Bressie ◽  
Ryan J. Pigg ◽  
Richard R. Rediske ◽  
...  

1977 ◽  
Vol 34 (10) ◽  
pp. 1878-1889 ◽  
Author(s):  
J. C. Schneider ◽  
J. H. Leach

Changes in walleye (Stizostedion vitreum vitreum) stocks in the Great Lakes from 1800 to 1975 were linked to proliferation of foreign species of fish and culturally induced sources of stress — exploitation, nutrient loading, alteration of spawning habitat, and toxic materials. During the 1800s, three small spawning stocks (and probably many others) were damaged or destroyed because of either overfishing or elimination of spawning habitat through logging, pollution, or damming.During 1900–40, stocks in the Michigan waters of Lake Superior, southern Green Bay, the Thunder Bay River of Lake Huron, the North Channel of Lake Huron, and the New York waters of Lake Ontario declined gradually. Pollution, in general, and degradation of spawning habitat, in particular, probably caused three of the declines and overexploitation was suspected in two instances. In addition, the decline of three of these stocks occurred when rainbow smelt (Osmerus mordax) were increasing.During 1940–75, stocks in seven areas declined abruptly: Saginaw Bay (1944), northern Green Bay (1953), Muskegon River (mid-1950s), western Lake Erie (1955), Nipigon Bay (late 1950s), Bay of Quinte (1960), and Black Bay (mid-1960s). The decline of each stock was associated with a series of weak year-classes. The stocks were exposed to various sources of stress, including overexploitation, pollution, and interaction with foreign species, which, if not important in the decline, may be suppressing recovery. Only the western Lake Erie stock recovered, in part due to a reduction in exploitation and, possibly, because of the relatively low density of smelt and alewives (Alosa pseudoharengus) in the nursery areas.Relatively stable stocks persisted in five areas: Wisconsin waters of Lake Superior, Lake St. Clair — southern Lake Huron, eastern Lake Erie, northern Lake Huron, and parts of Georgian Bay. Pollution problems were relatively minor in these areas and exploitation was light during recent decades. Apparently these stocks were more capable of withstanding the additional stresses exerted by alien species. Key words: population fluctuations, Percidae, Stizostedion, Great Lakes walleye, history of fisheries, summary of stresses, harvests, management implications


1986 ◽  
Vol 43 (2) ◽  
pp. 407-415 ◽  
Author(s):  
Claire L. Schelske ◽  
Eugene F. Stoermer ◽  
Gary L. Fahnenstiel ◽  
Mark Haibach

Our hypothesis that silica (Si) depletion in Lake Michigan and the severe Si depletion that characterizes the lower Great Lakes were induced by increased phosphorus (P) inputs was supported by bioassay experiments showing increased Si uptake by diatoms with relatively small P enrichments. We propose that severe Si depletion (Si concentrations being reduced to ≤0.39 mg SiO2∙L−1 prior to thermal stratification) results when P levels are increased to the extent that increased diatom production reduces Si concentrations to limiting levels during the thermally mixed period. Large P enrichments such as those that characterized the eastern and central basis of Lake Erie and Lake Ontario in the early 1970s are necessary to produce severe Si depletion. It is clear that severe Si depletion in the lower lakes was produced by P enrichment because inflowing waters from Lake Huron have smaller P concentrations and larger Si concentrations than the outflowing waters of either Lake Erie or Lake Ontario. Severe Si depletion probably began in the 1940s or 1950s as the result of increased P loads from expanded sewering of an increasing urban population and the introduction of phosphate detergents. The model proposed for biogeochemical Si depletion is consistent with previous findings of high rates of internal recycling because, under steady-state conditions for Si inputs, any increase in diatom production will produce an increase in permanent sedimentation of biogenic Si provided some fraction of the increased biogenic Si production is not recycled or unless there is a compensating increase in dissolution of diatoms.


1970 ◽  
Vol 7 (2) ◽  
pp. 628-633 ◽  
Author(s):  
R. H. Clark ◽  
N. P. Persoage

Movements of the earth's crust causing progressive changes in the levels of large bodies of water relative to their shorelines may influence the formulation of water resource projects and/or their continuing effectiveness with time. In the Great Lakes basin there is evidence of an uplift of the earth's crust, of about 1 ft per 100 y, in the northeasterly part of the basin relative to that in the southwest. This results in a corresponding lowering of water levels along the northeasterly shorelines and a rise in water levels along the southwest shores. In at least two of the lakes, Lake Huron and Lake Ontario, the average depth of water will change with time. In Lake Huron, it will gradually decrease because the bed underlying the lake is rising with respect to the lake outlet. In Lake Ontario, the depth of water will increase since the lake outlet is rising with respect to the remainder of the lake. This paper reviews some of the engineering implications of the relative rates of crustal movement in the Great Lakes region on long-term management of the water levels of the Great Lakes.


2000 ◽  
Vol 1 (4) ◽  
pp. 1
Author(s):  
Thorndike Saville, Jr.

The General Investigations program of the Beach Erosion Board comprises investigations, regional rather than local in scope, designed to improve, simplify, and expedite the solution of local problems, by giving a compilation of all existing data pertinent to shore processes in the particular region. As a first step in the compilation of these data, a study of wave and lake level conditions on the Great Lakes is being made. The results of such studies for Lake Michigan, Lake Erie, and Lake Ontario have recently been completed and published as Technical Memorandums of the Beach Erosion Board (Saville, 1953).


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