scholarly journals Zebra mussels negate or mask the increasing effects of nutrient enrichment on algal biomass: a preliminary mesocosm study

2009 ◽  
Vol 31 (11) ◽  
pp. 1437-1440 ◽  
Author(s):  
A. R. Dzialowski ◽  
W. Jessie
2013 ◽  
Vol 32 (2) ◽  
pp. 462-470 ◽  
Author(s):  
Andrew R. Dzialowski

2007 ◽  
Vol 64 (2) ◽  
pp. 227-238 ◽  
Author(s):  
Michael J Bowes ◽  
Jim T Smith ◽  
John Hilton ◽  
Michael M Sturt ◽  
Patrick D Armitage

Nutrient modification experiments were conducted in streamside flumes to determine the concentration at which P limits algal growth in the mesotrophic River Frome, Dorset, UK. The soluble reactive P (SRP) concentration in each flume was either increased (by P addition), decreased (by precipitating P with iron(II) sulphate solution), or left unaltered (control), producing SRP concentrations ranging from 32 to 420 µ·L–1. Increasing the ambient SRP concentration did not increase epilithic algal growth, showing that the River Frome was not P limited at 109 µ SRP·L–1. In the P-stripped flumes, algal biomass declined as the SRP concentration fell below ~90 µ·L–1, with a 60% biomass reduction at <40 µ SRP·L–1. Phosphorus-diffusing periphytometers deployed in the P-stripped flumes confirmed that reduced rates of algal growth were due to P limitation rather than a physical effect of FeSO4 addition. The ~90 µ·L–1 maximum P-limiting concentration is likely to be similar for comparable nutrient-impacted rivers. This iron-stripping approach expands the existing river nutrient-enrichment methodology so that it can be used in nutrient-impacted rivers and should allow catchment managers to produce knowledge-based P reduction targets prior to introducing remediation.


2005 ◽  
Vol 62 (1) ◽  
pp. 205-214 ◽  
Author(s):  
William J Edwards ◽  
Chris R Rehmann ◽  
Ellen McDonald ◽  
David A Culver

We used an acoustic Doppler profiler to investigate the hydrodynamics of a nearshore site in western Lake Erie, and we incorporated the measured parameters in numerical simulations of phytoplankton consumption by benthic zebra mussels (Dreissena polymorpha) to examine the link between pelagic production and benthic filter feeders. Daily-averaged eddy diffusivities varied from 10–5 to 10–4 m2·s–1 at our site. Our simulations demonstrate that diffusivities of this order decrease near-bed algal biomass, while algal biomass in the pelagic remains relatively unaffected. Between 8% and 67% of the algal biomass in the water column could be consumed daily, depending on the shape and magnitude of the diffusivity profile. Correspondingly, in situ vertical biomass profiles showed a near-bed zone of algal depletion, but no impact was observed near the surface. The impact of the zebra mussel in nearshore regions is expected to be stronger than in deeper open water. The flow of algal biomass into the benthos was tightly coupled with turbulent mixing, suggesting that open water algal consumption by zebra mussels is small compared with previously published estimates that ignored vertical turbulent mixing processes.


1976 ◽  
Vol 33 (7) ◽  
pp. 1553-1563 ◽  
Author(s):  
John G. Stockner ◽  
K. R. S. Shortreed

Attached algal growth in Carnation Creek and its estuary were monitored in 1974 and 1975 as part of the Carnation Creek Experimental Watershed Project. Net production on the estuary was 17.8 μg organic matter (org)∙cm−2∙day−1, and in Carnation Creek the average was 3.4 μg org∙cm−2∙day−1. Algal growth in Ritherdon Creek, located in an adjacent logged watershed, was slightly higher (4.6 μg org∙cm−2∙day−1) than the Carnation Creek average. In a streamside nutrient enrichment experiment, nitrate and phosphate concentrations in one trough were increased to twice the normal Carnation Creek values present in the control. In 35 days the nutrient-enriched trough had a total algal volume 3 times that of the control. It is suggested that extremely low nutrient concentrations (especially phosphate), and secondarily, poor light conditions under the canopy, are responsible for the paucity of algal growth in Carnation Creek. Major loss of algae from the system is caused by periodic freshets which scour the stream bed. Losses by grazing herbivorous insects were considered negligible. Dominant diatoms in Carnation Creek were Achnanthes minutissima, Synedra ulna, Hannaea arcus, Diatoma hiemale, and Eunotia pectinalis. Ulothrix sp., Draparnaldia sp., and Mougeotia sp. were the dominant filamentous green algae. Net production and algal biomass (chlorophyll a) in Carnation Creek are among the lowest ever reported in the literature.


2005 ◽  
Vol 164 (4) ◽  
pp. 449-464 ◽  
Author(s):  
W. Keith Taulbee ◽  
Scott D. Cooper ◽  
John M. Melack

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