The distribution of Chironomus (s.s.)? cucini (salinarius group) larvae (Diptera: Chironomidae) in Parry Sound, Georgian Bay, with particular reference to structural deformities

1976 ◽  
Vol 54 (12) ◽  
pp. 2129-2134 ◽  
Author(s):  
Landis Hare ◽  
John C. H. Carter
Keyword(s):  
Georgian Bay ◽  
Deep Cool ◽  
Morphological Deformities

The results of a study of the macroscopic zoobenthos in Parry Sound, Georgian Bay, Ontario, suggest that the larvae of Chironomus (s.s.)? cucini (salinarius group), which are present only in the deep cool regions below the summer thermocline, are most abundant when their environment has been 'altered' as a result of the activities of man. Furthermore, when these 'alterations' reach a too intense level larvae in this and other chironomid taxa may exhibit morphological deformities.

Waste Disposal in the Sea off Southern California

1986 ◽  
Vol 18 (11) ◽  
pp. 1-9 ◽  
Author(s):  
Willard Bascom
Keyword(s):  
Waste Water ◽  
Coastal Waters ◽  
Southern California ◽  
State Standards ◽  
Waste Streams ◽  
Cool Water ◽  
Water Research ◽  
The Pacific ◽  
Steady Improvement ◽  
Deep Cool

Southern California, with a coastal population of 12 million people, releases about 4.4 million cubic meters of treated waste water into the Pacific every day via outfalls that discharge three to six kilometers offshore at a depth of 60 meters. Diffusers cause each liter of waste to be diluted by 150 liters of deep cool water preventing it from reaching the surface except for short periods in winter. Data on the constituents of the four largest waste streams are presented and a brief account of the research done by the Southern California Coastal Water Research Project is given. Although the waste water now discharged meets rigorous state standards (with minor exceptions) and the steady improvement in sea conditions over a decade has been well documented, there is a continuing debate over whether our coastal waters are adequately protected. This is primarily because the damaging effects of DDT and PCBs that were discharged more than 14 years ago have been slow to go away. Although the amounts of DDT and PCB in sea animals are only one- tenth what they were a decade ago they tend to obscure the value of the improvements and the present discharge practices. The alternatives to sea disposal seem likely to cause greater damage to the overall environment.

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.

NOTES ON THE HEPTAGENINE SPECIES DESCRIBED BY CLEMENS FROM THE GEORGIAN BAY REGION, ONT. (EPHEMEROP.)

1933 ◽  
Vol 65 (1) ◽  
pp. 16-24 ◽  
Author(s):  
J. McDunnough
Keyword(s):  
Present Article ◽  
Georgian Bay

In order to clear up certain doubts which had arisen regarding the identity of several Heptagenine species, placed at present in the genus Ecdyonurus, and described by Clemens from material collected in the Go Home Bay region of the Georgian Bay (1913, Can. Ent. XLV, 246-262), Mr. G. S. Walley spent the months of June and July, 1932, in this same locality, collecting and breeding nymphal material. In the group in question he was most successful in securing both nymphs and bred adults of all the species listed by Clemens; the present article, therefore, is presented with a view not only of rendering definitely recognizable certain of Clemens' species in which the original diagnoses were rather brief and incomplete, but also of correcting some specific misidentifications occurring in Clemens' paper.

Failed predation in Late Ordovician gastropods (Mollusca) from Manitoulin Island, Ontario, CanadaThis article is one of a selection of papers published in this Special Issue on the theme The dynamic reef and shelly communities of the Paleozoic. This Special is in honour of our colleague and friend Paul Copper.

2008 ◽  
Vol 45 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Jan Ove R. Ebbestad ◽  
Christopher A. Stott
Keyword(s):  
Success Rate ◽  
Late Ordovician ◽  
Size Class ◽  
Low Energy ◽  
Special Issue ◽  
Georgian Bay ◽  
Low Level ◽  
Shell Repair ◽  
Number Of Individuals ◽  
Selection Of

Shell repairs resulting from presumed failed predation are documented in gastropods from the Late Ordovician (Cincinnatian; Richmondian) mid-to-upper Kagawong Submember of the Georgian Bay Formation on Manitoulin Island, Ontario, Canada. The bryozoan–mollusc biota and associated sediments generally suggest nearshore, shallow (<10 m), low energy (lagoonal), and perhaps mesotrophic to eutrophic conditions. Two sample sets from this unit have been studied for shell repair. One of the more commonly applied estimates of shell repair frequencies involves division of the number of individuals with at least one scar by the total number of individuals in the sample (the Individuals with scars method). Using this calculation, 207 specimens of Lophospira trilineata Ulrich and Scofield yielded a shell repair frequency of 4.8%; in 28 specimens of Trochonemella sp. the shell repair frequency was 35.7%. Repairs in Trochonemella occur primarily in the larger size class, suggesting that a size refuge was achieved by this species. Low repair frequencies in L. trilineata suggest predation with a higher success rate or fewer encounters. This study demonstrates that the paradigm of a standardized low level of shell repair in Ordovician and Silurian gastropods is oversimplistic and a range of frequency rates can be expected.

scholarly journals XII.: NOTES ON THE AQUATIC PLANTS OF GEORGIAN BAY.

1911 ◽  
Vol c (2) ◽  
pp. 219-220
Author(s):  
A. B. Klugh M.A.
Keyword(s):  
Aquatic Plants ◽  
Georgian Bay

not available

Dispersal and floating ability of dimorphic fruit segments of Cakile edentula var. lacustris

1981 ◽  
Vol 59 (12) ◽  
pp. 2595-2602 ◽  
Author(s):  
Anita M. Payne ◽  
M. A. Maun
Keyword(s):  
Water Waves ◽  
Sandy Beaches ◽  
Georgian Bay ◽  
New Locations ◽  
Waves And Currents ◽  
Cakile Edentula ◽  
Strong Winds

Cakile edentula (Bigel) Hook var. lacustris occurs abundantly along sandy beaches of Lakes Huron, Erie and Ontario. Until now the species had not been reported to occur along Georgian Bay but we located one population at Deanlea Beach. The deciduous upper fruit segments disperse long distances by water waves and currents and short distances by rolling caused by strong winds. The lower fruit segments usually remain attached to the parents which may be uprooted by high waves and then transported as tumble weeds to new locations. The floatation experiment showed that the agitation of jars containing the fruits improved their floating ability. Agitated upper fruit segments showed a significantly lower sinking index than agitated lower fruit segments and upper and lower fruit segments in the still treatment. The overwintering of fruits improved their floating ability.

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