Food and indicators of food availability for common terns on the lower Great Lakes

1980 ◽  
Vol 58 (7) ◽  
pp. 1318-1323 ◽  
Author(s):  
Peter A. Courtney ◽  
Hans Blokpoel
Keyword(s):  
Great Lakes ◽  
Food Availability ◽  
Brood Size ◽  
Lake Ontario ◽  
Niagara River ◽  
Common Terns ◽  
Western Lake ◽  
Acceptance Levels ◽  
Emerald Shiner ◽  
Foraging Time

The food of common terns (Sterna hirundo) nesting on the lower Great Lakes was studied in 1979. In western Lake Ontario 90% of the diet comprised alewife and smelt. In the Niagara River the principal food items were smelt, emerald shiner, common shiner, and bluntnose minnow and in eastern Lake Erie the principal items were smelt, emerald shiner, and trout-perch. Nonfish material was rarely observed. Methods for studying the diets of common terns on the Great Lakes are examined.Three indicators of food availability were examined in 1979 at the Eastern Headland in western Lake Ontario: (1) percentage fish accepted by chicks, (2) foraging time, and (3) chick growth. More food was presented to the chicks than they could eat. Food acceptance levels increased with chick age and brood size and ranged from 43.5 to 91.5%. Foraging trip times were 17.2 min on average and, depending on brood size, tern pairs spent an estimated 45–64% of daylight hours foraging for food for their chicks. Weights of 15-day-old chicks in three-chick broods were higher than those reported for other parts of the breeding range.

scholarly journals Status and Trends of the Lake Ontario Macrobenthos

1991 ◽  
Vol 48 (8) ◽  
pp. 1558-1567 ◽  
Author(s):  
Thomas F. Nalepa
Keyword(s):  
Great Lakes ◽  
River Mouth ◽  
Lake Ontario ◽  
The Other ◽  
Niagara River ◽  
Major River ◽  
Trends Over Time ◽  
The 1960S ◽  
River Mouths ◽  
The Impact

The benthic macroinvertebrate community of Lake Ontario was examined relative to communities found in the other Great Lakes and also relative to trends over time. In the nearshore, populations are heavily influenced by municipal and industrial inputs. For example, oligochaete abundances in the nearshore are higher than in any of the other Great Lakes (excluding shallow Lake Erie), communities have been altered even to relatively deep depths near the major river mouths, and the pollution-sensitive Pontoporeia hoyi is scarce along the southern shoreline east of the Niagara River mouth. In the profundal, benthic composition is similar to that found in the other Great Lakes, but biomass is less than might be expected given the amount of organic material settling to the bottom. Benthic standing stocks in this region have apparently declined almost threefold since the 1960s. Reasons for this decline do not appear to be related to trends in water column productivity or to predation pressure, but may be related to the accumulation of contaminants. Research needs include studies to assess benthic trends over a much broader area of the lake and studies to examine the impact of sublethal levels of contaminants.

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
Keyword(s):  
Great Lakes ◽  
Lake Erie ◽  
Lake Ontario ◽  
Growth Potential ◽  
Great Lakes Basin ◽  
Detroit River ◽  
Quagga Mussels ◽  
Western Lake ◽  
Time Period ◽  
Highly Correlated

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.

Late glacial and postglacial geology in the Lake Ontario basin

1984 ◽  
Vol 21 (7) ◽  
pp. 802-821 ◽  
Author(s):  
P. G. Sly ◽  
J. Wyn Prior
Keyword(s):  
Thick Layer ◽  
Lake Ontario ◽  
Late Glacial ◽  
Western Basin ◽  
Niagara River ◽  
Lacustrine Deposits ◽  
Western Lake ◽  
Ice Wedge ◽  
Lacustrine Clay ◽  
East End

Western Lake Ontario sediments record a till–mud–till sequence over bedrock and a thick layer of partly distorted glaciolacustrine clay unconformably overlying this. Another unconformity separates this clay from younger fine (lacustrine?) deposits, which are also distorted. Modern foreset and bottomset beds of the Niagara River overlap the lacustrine and glaciolacustrine deposits.In eastern Lake Ontario, thick glaciolacustrine clays overlie bedrock and the infilling ice-marginal deposits. These glaciolacustrine clays are severely distorted, and in the deepest parts of the area patches of overlying lacustrine (?) clay are preserved. A distorted terracelike deposit is preserved at higher elevation in the St. Lawrence trough. Bedrock, lag gravels, and sandy deposits characterize shallow-water areas.We suggest that after the fall of lake levels in the Lake Ontario basin, during the post-Iroquois lake phases, glaciolacustrine clays were subject to distortion by ice action at the time of the Greatlakean stadial. This deformation was more severe at the east end of the basin. At its lowest level, the surface of early Lake Ontario following the post-Iroquois phases was below the present lakebed in much of western Lake Ontario. Ice-wedge casts formed in sediments at both ends of the basin, soon after the initiation of early Lake Ontario, and are correlated with the Algonquin (St. Narcisse) glacial phase. Whereas there are significant accumulations of modern mud in the western basin of Lake Ontario, in the Kingston basin there is little except in the St. Lawrence trough.

Impact of Proposed Burlington and Hamilton Sewage Discharges in Western Lake Ontario

2003 ◽  
Vol 38 (4) ◽  
pp. 627-645 ◽  
Author(s):  
Yerubandi R. Rao ◽  
Raj C. Murthy ◽  
Fausto Chiocchio ◽  
Michael G. Skafel ◽  
Murray N. Charlton
Keyword(s):  
Action Plan ◽  
Near Field ◽  
Lake Ontario ◽  
Zone Model ◽  
Hamilton Harbour ◽  
Western Lake ◽  
Treated Sewage ◽  
Treated Effluents ◽  
Typical Summer ◽  
The City

Abstract The alternate strategy of open-lake discharge may alleviate the need for unusually stringent treatment needed to meet water quality goals of the Hamilton Harbour Remedial Action Plan (RAP). The latest update of the RAP recommended a study of the possibility of offshore discharges. A study conducted for the City of Burlington has proposed a location for outfall in Lake Ontario. This paper utilizes a combination of physical limnological data and mathematical models to predict the waste plume characteristics for the proposed outfall in the lake. Near-field dilutions obtained from a mixing zone model show that, for treated effluents with a discharge condition of 2 m3/s at the proposed outfall site at Burlington, the dilution ratios are in the range of 13:1 to 28:1 for weak to moderate currents during summer stratification. Winter dilution ratios increased to 21:1 to 96:1 for moderate currents. The recommended site for open-lake outfall provides acceptable near-field dilutions for treated effluents under typical lake currents and density structure. The extension of outfall to a location farther offshore is only marginally beneficial. With the proposed Burlington outfall location and discharge conditions, no far-field contamination is observed near the beaches or nearby water intakes for typical summer and winter conditions. Thus, this study indicates that by discharging the treated sewage from an outfall in Lake Ontario it is possible to achieve the Hamilton Harbour RAP goals.

Identification of Taste and Odour Compounds from Western Lake Ontario

1984 ◽  
Vol 19 (1) ◽  
pp. 111-118 ◽  
Author(s):  
B.G. Brownlee ◽  
D.S. Painter ◽  
R.J. Boone
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Elemental Sulfur ◽  
Lake Ontario ◽  
Direct Link ◽  
Municipal Water Supply ◽  
Municipal Water ◽  
Western Lake ◽  
Odour Concentration

Abstract During August, 1983 geosmin was identified in a municipal water supply drawn from western Lake Ontario. The geosmin concentrations were 0.01-0.07 μg L-1, within the range for threshold odour concentration of 0.01-0.2 μg L-1. 2-Methylisoborneol was not detected. The odour 'event' coincided with a dieoff of Cladophora in the lake, but we were not able to establish a direct link between the dieoff and geosmin production. Decomposing Cladophora in shoreline areas produced a strong odour in the air. 3-Methylindole, elemental sulfur, dimethyl tetrasulfide, and dimethyl pentasulfide were tentatively identified in water samples collected from these areas, but geosmin and 2-methylisoborneol were not detected.

Zebra Mussels as Biomonitors for Organic Contaminants in the Lower Great Lakes

1996 ◽  
Vol 31 (2) ◽  
pp. 411-432 ◽  
Author(s):  
Michael E. Comba ◽  
Janice L. Metcalfe-Smith ◽  
Klaus L.E. Kaiser
Keyword(s):  
Great Lakes ◽  
Organic Contaminants ◽  
Lake Erie ◽  
Soft Tissues ◽  
Lake Ontario ◽  
Dry Weight ◽  
Zebra Mussels ◽  
Organic Contamination ◽  
Contamination Levels ◽  
St Lawrence River

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.

Evidence of successful river spawning by lake trout (Salvelinus namaycush) in the Lower Niagara River, Lake Ontario

2021 ◽  
Author(s):  
Alexander Gatch ◽  
Dimitry Gorsky ◽  
Zy Biesinger ◽  
Eric Bruestle ◽  
Kelley Lee ◽  
...  
Keyword(s):  
Lake Trout ◽  
Lake Ontario ◽  
Salvelinus Namaycush ◽  
Niagara River
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