|
PEARLPaleoecologicalEnvironmentalAssessment andResearchLaboratory |
|
|
|
PEARLPaleoecologicalEnvironmentalAssessment andResearchLaboratory |
|
Seasonal patterns in
metal levels of the net plankton of three
The Science of the
Total Environment. 87/88: 439-461.
Within a broader analysis of metal
levels in crustacean zooplankton,
calcium concentrations of daphniids were noted to be significantly
higher than other taxonomic groups
The effect of calcium concentration on the calcification of Daphnia
magna.
Limnology and Oceanography. 44:
2011-2017.
Experimental studies on the calcification and calcium content of Daphnia magna clearly suggest the
potential of calcium limitation.
Hessen, D.O., Alstad,
N.E.W., and Skardal, L. 2000.
Calcium limitation in Daphnia magna.
Journal of Plankton Research. 22:
553-568.
Threshold calcium levels required for the
survival of the hardwater species Daphnia
magna found to be in the 0.1-0.5 mg/L range. Age-specific egg
production strongly reduced at Ca concentrations <10 mg/L.
Keller, W., Dixit, S.S., and Heneberry, J. 2001.
Calcium declines in northeastern Ontario lakes.
Canadian Journal of Fisheries and Aquatic Sciences. 58: 2011-2020.
Inferred
historical lakewater calcium concentrations using diatoms as a
paleolimnological indicator for six lakes near Sudbury, Ontario showing
large declines through much of the 20th century.
Waervagen,
S.B.,
Rukke, N.A., and Hessen, D.O. 2002.
Calcium content of
crustacean zooplankton and its potential role in species distribution.
Freshwater Biology. 47: 1866-1878.
A regional study of Norwegian
lakes showing aqueous calcium concentration to influence the
distribution of Daphnia species and calcium content
to differ among species.
(This study combined with observed declines in aqueous calcium
concentrations of the
Dorset A-lakes prompted Dr. Norman Yan to have a Masters student
examine calcium concentration differences in
---
Jeziorski, A. and
Species identity and
aqueous calcium concentrations as determinants of calcium
concentrations of
freshwater crustacean zooplankton.
Canadian Journal of
Fisheries and Aquatic Sciences. 63:
1007-1013.
A field study examining the
calcium concentrations of eight crustacean zooplankton species from
nine
lakes on the Canadian Shield. Species identity was more important
in determining crustacean zooplankton calcium concentration than either
lake calcium concentration or seasonality (Daphnia spp. had much greater calcium levels than any of
the other
species).
---
Jeziorski,
A.,
Calcium levels
in
Daphnia ephippia cannot provide a useful paleolimnological indicator of
historical Lakewater Ca concentrations.
Journal of
Paleolimnology. 39: 421-425.
An attempt to apply the
species-specific Ca concentration of crustacean zooplankton in a
paleolimnological approach using their ephippia (resting eggs) that
proved to be
quite difficult due to the low levels of calcium in the ephippia.
---
DeSellas, A.M.,
Paterson, A.M., Sweetman, J.N., and Smol, J.P. 2008
Cladocera assemblages
from the surface sediments of south-central
Hydrobiologia. 600: 105-119.
A "Top-Bottom" paleolimnological
analysis of crustacean zooplankton
assemblages from 44 lakes in South-central Ontario found calcium to be
one of the
five environmental variables significantly influencing assemblage
composition
(along with SO4, pH, Zmax and DOC).
---
Ashforth, D. and
The interactive
effects of calcium concentrations and temperature on the survival and
reproduction of Daphnia pulex at high and low food concentrations.
Limnology and
Oceanography. 53: 420-432.
Examined
the calcium needs of Daphnia pulex (the species that
had the highest calcium content of the 8
examined in Jeziorski and Yan, 2006) in
a laboratory setting and identified a 1.5 mg/L
performance
threshold.
The widespread threat
of calcium decline in fresh waters.
Science. 322: 1374-1377.
Documented near extirpations of
calcium-rich Daphnia spp., in sediment cores from
lakes with calcium concentrations that have recently fallen below
1.5mg/L. A
large proportion (62 %; 47-81 % by region) of the 770
|
|