Influence of Salmonine Predation and Weather on Long-Term Water Quality Trends in Lake Michigan

1986 ◽  
Vol 43 (2) ◽  
pp. 435-443 ◽  
Author(s):  
Donald Scavia ◽  
Gary L. Fahnenstiel ◽  
Marlene S. Evans ◽  
David J. Jude ◽  
John T. Lehman
Keyword(s):  
Water Quality ◽  
Management Practices ◽  
Lake Michigan ◽  
Sediment Resuspension ◽  
Weather Conditions ◽  
Water Clarity ◽  
Alosa Pseudoharengus ◽  
Calanoid Copepods ◽  
Chl A ◽  
Secchi Disk Transparency

Trends in Lake Michigan water quality over 1975–84 appear to reflect reduced nutrient loadings as indicated by gradual declines in spring total phosphorus (TP) and summer epilimnetic chlorophyll a (Chl a). Deviations from these trends during 1977 and 1983–84 were apparently caused by abiotic and biotic factors, respectively. Prolonged ice cover during 1977 decreased sediment resuspension resulting in lower TP, reduced Chl a levels, and increased water clarity. A similar dramatic result occurred in 1983 and to a lesser extent in 1984, but via a different mechanism. Burgeoning populations of stocked salmonines reduced populations of the planktivorous alewife (Alosa pseudoharengus), which allowed large Daphnia to flourish. Because the Daphnia are more voracious and nonselective grazers than the formerly dominant calanoid copepods, they reduced seston concentrations, causing dramatic increases in Secchi disk transparency. These exceptions demonstrate the far-reaching consequences that unusual weather conditions and fish management practices may have on water quality indicators.

scholarly journals Physical and biogeochemical controls on light attenuation in a eutrophic, back-barrier estuary

2014 ◽  
Vol 11 (8) ◽  
pp. 12183-12221 ◽  
Author(s):  
N. K. Ganju ◽  
J. L. Miselis ◽  
A. L. Aretxabaleta
Keyword(s):  
Light Attenuation ◽  
Sediment Resuspension ◽  
Water Clarity ◽  
High Temporal Resolution ◽  
Barnegat Bay ◽  
Chl A ◽  
Seagrass Meadows ◽  
Boat Traffic ◽  
The Difference ◽  
Shallow Estuaries

Abstract. Light attenuation is a critical parameter governing the ecological function of shallow estuaries. In these systems primary production is often dominated by benthic macroalgae and seagrass; thus light penetration to the bed is of primary importance. We quantified light attenuation in three seagrass meadows in Barnegat Bay, New Jersey, a shallow eutrophic back-barrier estuary; two of the sites were located within designated Ecologically Sensitive Areas (ESAs). We sequentially deployed instrumentation measuring photosynthetically active radiation, chlorophyll a (chl a) fluorescence, dissolved organic matter fluorescence (fDOM; a proxy for colored DOM absorbance), turbidity, pressure, and water velocity at 10 min intervals over three week periods at each site. At the southernmost site, where sediment availability was highest, light attenuation was highest and dominated by turbidity and to a lesser extent chl a and CDOM. At the central site, chl a dominated followed by turbidity and CDOM, and at the northernmost site turbidity and CDOM contributed equally to light attenuation. At a given site, the temporal variability of light attenuation exceeded the difference in median light attenuation at the three sites, indicating the need for continuous high-temporal resolution measurements. Vessel wakes, anecdotally implicated in increasing sediment resuspension, did not contribute to local resuspension within the seagrass beds, though frequent vessel wakes were observed in the channels. With regards to light attenuation and water clarity, physical and biogeochemical variables appear to outweigh any regulation of boat traffic within the ESAs.

scholarly journals Assessment of Water Quality Based on Trophic Status and Nutrients-Chlorophyll Empirical Models of Different Elevation Reservoirs

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3640
Author(s):  
Md Mamun ◽  
Usman Atique ◽  
Kwang-Guk An
Keyword(s):  
Water Quality ◽  
Trophic State ◽  
Trophic Status ◽  
Water Clarity ◽  
Empirical Models ◽  
Cyanobacterial Blooms ◽  
Anthropogenic Factors ◽  
Trophic State Index ◽  
Chl A ◽  
State Index

Water quality degradation is one of the most pressing environmental challenges in reservoirs around the world and makes the trophic status assessment of reservoirs essential for their restoration and sustainable use. The main aims of this study were to determine the spatial variations in water quality and trophic state of 204 South Korean reservoirs at different altitude levels. The results demonstrated mean total phosphorus (TP), chlorophyll-a (CHL-a), total suspended solids (TSS), organic matter indicators (chemical oxygen demand: COD; total organic carbon: TOC), water temperature (WT), and electrical conductivity (EC) remain consistently higher in the very lowland reservoirs (VLLR) than those in other altitudes, due to sedimentary or alluvial watersheds. The average TP and CHL-a levels in VLLR crossed the limit of the eutrophic water, symptomizing a moderate risk of cyanobacterial blooms. Empirical models were developed to identify critical variables controlling algal biomass and water clarity in reservoirs. The empirical analyses of all reservoir categories illustrated TP as a better predictor of CHL-a (R2 = 0.44, p < 0.01) than TN (R2 = 0.02, p < 0.05) as well as showed strong P-limitation based on TN:TP ratios. The algal productivity of VLLR (R2 = 0.61, p < 0.01) was limited by phosphorus, while highland reservoirs (HLR) were phosphorus (R2 = 0.23, p < 0.03) and light-limited (R2 = 0.31, p < 0.01). However, TSS showed a highly significant influence on water clarity compared to TP and algal CHL-a in all reservoirs. TP and TSS explained 47% and 34% of the variance in non-algal turbidity (NAT) in HLR. In contrast, the TP and TSS variances were 18% and 29% in midland reservoirs (MLR) and 32% and 20% in LLR. The trophic state index (TSI) of selected reservoirs varied between mesotrophic to eutrophic states as per TSI (TP), TSI (CHL-a), and TSI (SD). Mean TSI (CHL-a) indicated all reservoirs as eutrophic. Trophic state index deviation (TSID) assessment also complemented the phosphorus limitation characterized by the blue-green algae (BGA) domination in all reservoirs. Overall, reservoirs at varying altitudes reflect the multiplying impacts of anthropogenic factors on water quality, which can provide valuable insights into reservoir water quality management.

scholarly journals Physical and biogeochemical controls on light attenuation in a eutrophic, back-barrier estuary

2014 ◽  
Vol 11 (24) ◽  
pp. 7193-7205 ◽  
Author(s):  
N. K. Ganju ◽  
J. L. Miselis ◽  
A. L. Aretxabaleta
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Light Attenuation ◽  
Sediment Resuspension ◽  
Water Clarity ◽  
Chl A ◽  
Seagrass Meadows ◽  
Boat Traffic ◽  
The Difference ◽  
Shallow Estuaries

Abstract. Light attenuation is a critical parameter governing the ecological function of shallow estuaries. In these systems primary production is often dominated by benthic macroalgae and seagrass; thus light penetration to the bed is of primary importance. We quantified light attenuation in three seagrass meadows in Barnegat Bay, New Jersey, a shallow eutrophic back-barrier estuary; two of the sites were located within designated Ecologically Sensitive Areas (ESAs). We sequentially deployed instrumentation measuring photosynthetically active radiation, chlorophyll a (chl a) fluorescence, dissolved organic matter fluorescence (fDOM; a proxy for colored dissolved organic matter (CDOM) absorbance), turbidity, pressure, and water velocity at 10 min intervals over 3-week periods at each site. At the southernmost site, where sediment availability was highest, light attenuation was highest and dominated by turbidity and to a lesser extent chl a and CDOM. At the central site, chl a dominated followed by turbidity and CDOM, and at the northernmost site turbidity and CDOM contributed equally to light attenuation. At a given site, the temporal variability of light attenuation exceeded the difference in median light attenuation between the three sites. Vessel wakes, anecdotally implicated in increasing sediment resuspension, did not contribute to local resuspension within the seagrass beds, though frequent vessel wakes were observed in the channels. With regards to light attenuation and water clarity, physical and biogeochemical variables appear to outweigh any regulation of boat traffic within the ESAs.

Dynamics of Lake Michigan Plankton: A Model Evaluation of Nutrient Loading, Competition, and Predation

1988 ◽  
Vol 45 (1) ◽  
pp. 165-177 ◽  
Author(s):  
Donald Scavia ◽  
Gregory A. Lang ◽  
James F. Kitchell
Keyword(s):  
Species Interactions ◽  
Lake Michigan ◽  
Nutrient Loading ◽  
Substantial Contribution ◽  
Alosa Pseudoharengus ◽  
Calanoid Copepods ◽  
Nutrient Excretion ◽  
Blue Green Algae ◽  
Phytoplankton Species Composition ◽  
Alternative Hypotheses

Lake Michigan's offshore ecosystem has been altered dramatically during the past decade. Summer zooplankton dominance has changed from calanoid copepods to Daphnia and the substantial contribution of filamentous blue-green algae to summer phytoplankton has been replaced by phytoflagellates. These changes occurred concurrently with reduced P load, P concentration, and abundance of the dominant zooplanktivore, the alewife (Alosa pseudoharengus). In this analysis we pose alternative hypotheses of nutrient loading and species interactions as determinants of zooplankton and phytoplankton species composition in the summer epilimnion. We evaluate these hypotheses with a food web model that was calibrated to measurements of the 1980s Lake Michigan plankton composition and algal production, sedimentation, and growth rates and literature estimates of zooplankton secondary production and nutrient excretion. The model simulates the influence of gradients of both P load and alewife abundance on predation–competition interactions. We conclude that summer plankton composition in Lake Michigan is controlled largely by predation. The model further predicts a return to a plankton community similar to that of the 1970s under a scenario of increasing invertebrate predation by a new zooplankton species for Lake Michigan, Bythotrephes cederstroemi.

Feeding-Behavior Repertoire of the Alewife, Alosa pseudoharengus, and the Ciscoes Coregonus hoyi and C. artedii

1978 ◽  
Vol 35 (2) ◽  
pp. 249-253 ◽  
Author(s):  
John Janssen
Keyword(s):  
Great Lakes ◽  
Feeding Behavior ◽  
Key Words ◽  
Lake Michigan ◽  
Alosa Pseudoharengus ◽  
Calanoid Copepods ◽  
Mysis Relicta ◽  
Particulate Feeding ◽  
Coregonus Hoyi

Particulate feeding, where fish orient to and take prey one at a time, is shown by the alewife, Alosa pseudoharengus, and the ciscoes Coregonus hoyi and C. artedii. Specialized particulate feeding is found in ciscoes and alewives for capturing strongly swimming prey such as Mysis relicta and calanoid copepods. This involves simultaneous darting and sucking. Alewives filter feed by swimming with the mouth fully agape for 0.5–2 s while driving hard with the tail. Ciscoes do not filter feed, but they and alewives display gulping behavior where fish open and close the mouth 2–3 times/s, do not drive hard with the tail, and may take more than one prey per gulp. The alewife has difficulty feeding near or on the bottom. The ciscoes feed easily on or near the bottom and will also take buried prey. Key words: Alosa pseudoharengus, Coregonus hoyi, C. artedii, feeding behavior, Great Lakes, Lake Michigan

Spatial variation in trophic structure of nearshore fishes in Lake Michigan as it relates to water clarity

2019 ◽  
Vol 76 (3) ◽  
pp. 364-377 ◽  
Author(s):  
Benjamin A. Turschak ◽  
Sergiusz Czesny ◽  
Jason C. Doll ◽  
Brice K. Grunert ◽  
Tomas O. Höök ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Round Goby ◽  
Water Clarity ◽  
Michigan Basin ◽  
Alosa Pseudoharengus ◽  
N Isotopes ◽  
C And N ◽  
Nearshore Fishes

Nearshore water clarity, as measured by remotely sensed Kd(490), and stable C and N isotopes of several nearshore fishes differed across the Lake Michigan basin. Values of δ13C of round goby (Neogobius melanstomus), yellow perch (Perca flavescens), and spottail shiner (Notropis hudsonis) were depleted in the southeast where water clarity was low relative to the southwest where water clarity was greater. Bayesian analyses were used to evaluate spatial variation in diet composition and quantify the relationship between water clarity and the proportional importance of pelagic energy in fish diets. Water clarity in nearshore areas is likely related to variable riverine inputs, resuspension, and upwelling processes. While these processes may not directly impact δ13C or δ15N of nearshore fishes, we hypothesize that water clarity differentially affects benthic and pelagic algal production. Lower water clarity in the benthos and subsequently lower benthic productivity may be related to regional diet differences and increased reliance on pelagic energy sources. Mobile fishes such as alewife (Alosa pseudoharengus) may not be in isotopic equilibrium with regional prey sources and depart from spatial patterns observed in other nearshore fishes.

Monitoring spatiotemporal variability of water quality parameters Using Landsat imagery in Choghakhor International Wetland during the last 32 years

2020 ◽  
Vol 56 ◽  
pp. 6
Author(s):  
Ahmad Reza Pirali Zefrehei ◽  
Aliakbar Hedayati ◽  
Saeid Pourmanafi ◽  
Omid Beyraghdar Kashkooli ◽  
Rasoul Ghorbani
Keyword(s):  
Water Quality ◽  
Landsat Imagery ◽  
Quality Parameters ◽  
Freshwater Ecosystems ◽  
Spatiotemporal Variability ◽  
Chl A ◽  
Secchi Disk Transparency ◽  
Small Water ◽  
Long Term Changes

Use of Landsat is of importance in monitoring and assessment of long-term changes of water quality in freshwater ecosystems, especially in small water bodies. In this study, over a 32-year period (1985–2017), the changes in water surface temperature (WST), secchi disk transparency (SDT), and chlorophyll-a (Chl-a) concentration were estimated at the Choghakhor wetland using Landsat imagery. Based on WST three detectable temperature zones can be observed within the wetland aquatic environment where the highest amount was observed in thermal strips. The results showed Chl-a concentration volatility in different periods in the wetland as well as its long-term increasing trend. The western part of the wetland, as compared to other areas, was affected by these changes, which could be due to the human activity concentrated in this area. In contrast (SDT) showed a decreasing trend during this period that was consistent with the observed changes in Chl-a concentration. This could be due to an increase in organic matter load and suspended solids in the water body of wetland during this time. Comparison of the extracted satellite data with the field data showed the least RMSE and high R2. Also, ANOVA results showed significant spatio-temporal differences between the studied parameters in Choghakhor wetland (p < 0.05). The present study can help to detect long-term changes in Choghakhor wetland and help toward moving to optimal management and protection of this wetland.

Water quality of Tampa Bay, Florida : wet-weather conditions, October 1971

1975 ◽  
Author(s):  
Carl R. Goodwin ◽  
Joseph S. Rosenshein ◽  
D.M. Michaelis
Keyword(s):  
Water Quality ◽  
Weather Conditions ◽  
Tampa Bay ◽  
Wet Weather

A Survey of Nursery Water Quality Best Management Practices

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501e-502
Author(s):  
Cody J. White ◽  
Michael A. Schnelle ◽  
Gerrit W. Cuperus
Keyword(s):  
Water Quality ◽  
Best Management Practices ◽  
Management Practices ◽  
Cultural Practices ◽  
Plant Materials ◽  
Best Management ◽  
Employee Safety ◽  
Current Water ◽  
Management Approaches ◽  
Environmentally Sound

A survey was designed to assess high-risk areas with respect to environmental contamination, specifically how it relates to water quality. Oklahoma growers of all economic levels, retail and/or wholesale, were queried at their place of business for their current state of implementing best management practices (BMPs) and other strategic actions that could potentially affect current and future water quality standards. Specific areas such as the physical environment of the nursery, primary pesticides and fertilizers used, Integrated Pest Management (IPM) practices, and employee safety training were covered as well as other aspects germane to preserving and protecting current water quality and related environmental issues. More than 75 nurseries were surveyed and given the opportunity to participate in future training at Oklahoma State Univ. Results indicated that nurseries have not fully implemented many BMPs, but have adopted fundamental IPM approaches. The stage is set for the implementation of the next phase of expansion and refinement into ecologically based programs such as propagation and sale of low pesticide input plant materials, improved cultural practices, and the integration of environmentally sound management approaches. As an example, many growers are in the process of phasing out calendar-based pesticide application programs in favor of aesthetic and/or economic threshold-driven pesticide spray programs.

Applying the Soil Water Assessment Tool to 5th Canadian Division Support Base Gagetown

2014 ◽  
Vol 49 (4) ◽  
pp. 372-385
Author(s):  
Shawn Burdett ◽  
Michael Hulley ◽  
Andy Smith
Keyword(s):  
Water Quality ◽  
Soil Water ◽  
Land Management ◽  
Management Practices ◽  
Assessment Tool ◽  
Anthropogenic Activities ◽  
Quality Model ◽  
Sediment Yields ◽  
Soil Water Assessment Tool ◽  
Water Assessment

A hydrologic and water quality model is sought to establish an approach to land management decisions for a Canadian Army training base. Training areas are subjected to high levels of persistent activity creating unique land cover and land-use disturbances. Deforestation, complex road networks, off-road manoeuvres, and vehicle stream crossings are among major anthropogenic activities observed to affect these landscapes. Expanding, preserving and improving the quality of these areas to host training activities for future generations is critical to maintain operational effectiveness. Inclusive to this objective is minimizing resultant environmental degradation, principally in the form of hydrologic fluctuations, excess erosion, and sedimentation of aquatic environments. Application of the Soil Water Assessment Tool (SWAT) was assessed for its ability to simulate hydrologic and water quality conditions observed in military landscapes at 5th Canadian Division Support Base (5 CDSB) Gagetown, New Brunswick. Despite some limitations, this model adequately simulated three partial years of daily watershed outflow (NSE = 0.47–0.79, R2 = 0.50–0.88) and adequately predicted suspended sediment yields during the observation periods (%d = 6–47%) for one highly disturbed sub-watershed in Gagetown. Further development of this model may help guide decisions to develop or decommission training areas, guide land management practices and prioritize select landscape mitigation efforts.

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