Beginning of the Nipissing Phase of Lake Huron

1958 ◽  
Vol 66 (5) ◽  
pp. 591-594 ◽  
Author(s):  
Aleksis Dreimanis
Keyword(s):  
Lake Huron ◽  
Nipissing Phase

scholarly journals Toxins and Other Bioactive Metabolites in Deep Chlorophyll Layers Containing the Cyanobacteria Planktothrix cf. isothrix in Two Georgian Bay Embayments, Lake Huron

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 445
Author(s):  
Arthur Zastepa ◽  
Todd R. Miller ◽  
L. Cynthia Watson ◽  
Hedy Kling ◽  
Susan B. Watson
Keyword(s):  
Thermal Stratification ◽  
Chemical Defence ◽  
Euphotic Zone ◽  
Lake Huron ◽  
Metabolic Inhibitors ◽  
Bioactive Metabolites ◽  
Total Biomass ◽  
Key Factors ◽  
Georgian Bay ◽  
And Function

The understanding of deep chlorophyll layers (DCLs) in the Great Lakes—largely reported as a mix of picoplankton and mixotrophic nanoflagellates—is predominantly based on studies of deep (>30 m), offshore locations. Here, we document and characterize nearshore DCLs from two meso-oligotrophic embayments, Twelve Mile Bay (TMB) and South Bay (SB), along eastern Georgian Bay, Lake Huron (Ontario, Canada) in 2014, 2015, and 2018. Both embayments showed the annual formation of DCLs, present as dense, thin, metalimnetic plates dominated by the large, potentially toxic, and bloom-forming cyanobacteria Planktothrix cf. isothrix. The contribution of P. cf. isothrix to the deep-living total biomass (TB) increased as thermal stratification progressed over the ice-free season, reaching 40% in TMB (0.6 mg/L at 9.5 m) and 65% in South Bay (3.5 mg/L at 7.5 m) in 2015. The euphotic zone in each embayment extended down past the mixed layer, into the nutrient-enriched hypoxic hypolimnia, consistent with other studies of similar systems with DCLs. The co-occurrence of the metal-oxidizing bacteria Leptothrix spp. and bactivorous flagellates within the metalimnetic DCLs suggests that the microbial loop plays an important role in recycling nutrients within these layers, particularly phosphate (PO4) and iron (Fe). Samples taken through the water column in both embayments showed measurable concentrations of the cyanobacterial toxins microcystins (max. 0.4 µg/L) and the other bioactive metabolites anabaenopeptins (max. ~7 µg/L) and cyanopeptolins (max. 1 ng/L), along with the corresponding genes (max. in 2018). These oligopeptides are known to act as metabolic inhibitors (e.g., in chemical defence against grazers, parasites) and allow a competitive advantage. In TMB, the 2018 peaks in these oligopeptides and genes coincided with the P. cf. isothrix DCLs, suggesting this species as the main source. Our data indicate that intersecting physicochemical gradients of light and nutrient-enriched hypoxic hypolimnia are key factors in supporting DCLs in TMB and SB. Microbial activity and allelopathy may also influence DCL community structure and function, and require further investigation, particularly related to the dominance of potentially toxigenic species such as P. cf. isothrix.

Zooplankton Grazing During the Zebra Mussel ( Dreissena polymorpha ) Colonization of Saginaw Bay, Lake Huron

1995 ◽  
Vol 21 (4) ◽  
pp. 567-573 ◽  
Author(s):  
Thomas B. Bridgeman ◽  
Gary L. Fahnenstiel ◽  
Gregory A. Lang ◽  
Thomas F. Nalepa
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Huron ◽  
Zooplankton Grazing ◽  
Saginaw Bay

Mercury accumulation in sea lamprey (Petromyzon marinus) from Lake Huron

2014 ◽  
Vol 470-471 ◽  
pp. 1313-1319 ◽  
Author(s):  
Charles P. Madenjian ◽  
Nicholas S. Johnson ◽  
Michael J. Siefkes ◽  
John M. Dettmers ◽  
Joel D. Blum ◽  
...  
Keyword(s):  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Lake Huron ◽  
Mercury Accumulation

Cross-basin comparison of mercury bioaccumulation in Lake Huron lake trout emphasizes ecological characteristics

2014 ◽  
Vol 34 (2) ◽  
pp. 355-359 ◽  
Author(s):  
Rachel A. Abma ◽  
Gordon Paterson ◽  
Anne McLeod ◽  
G. Doug Haffner
Keyword(s):  
Lake Trout ◽  
Lake Huron ◽  
Ecological Characteristics ◽  
Mercury Bioaccumulation
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