Grantee Research Project Results
1998 Progress Report: The Role of Long-Lived Zooplankton Diapausing Eggs Response and Recovery of Impacted Lakes
EPA Grant Number: R824771Title: The Role of Long-Lived Zooplankton Diapausing Eggs Response and Recovery of Impacted Lakes
Investigators: Hairston Jr., Nelson G. , Mills, Edward L.
Institution: Cornell University
EPA Project Officer: Packard, Benjamin H
Project Period: March 1, 1996 through February 1, 1999
Project Period Covered by this Report: March 1, 1997 through February 1, 1998
Project Amount: $350,000
RFA: Water and Watersheds (1995) RFA Text | Recipients Lists
Research Category: Watersheds , Water
Objective:
This research is an investigation of the role that long-lived dormant eggs play in influencing the ability of lake ecosystems to recover from human impact. To this end, we explore the diversity, abundance, age, and viability of zooplankton dormant eggs in two lakes in New York State: one that has a long history of heavy metal pollution (Onondaga Lake), and another (reference lake, Oneida Lake) that is relatively unimpacted. The progress made on this research during the third year of funding is reported below.Progress Summary:
In the first and second years of funding, we obtained and analyzed four 1-meter sediment cores for zooplankton egg densities and heavy metal concentrations, two from Onondaga Lake and two from Oneida Lake. In addition, 12 short cores were collected, 6 along 2 transects in each lake for similar analyses. All diapausing eggs retrieved were incubated to determine hatching and viability. In situ sediment emergence traps were deployed along deep and shallow transects in both lakes and monitored for the duration of the ice-free season to determine the timing of emergence, the impact of emergence on water-column plankton dynamics, and the effect of sediment mixing on emergence rate. These data are largely complete?some results have been published, some have been submitted for publication, and some are still being analyzed statistically.A striking pattern in the sediments of Onondaga Lake is the disappearance of native Daphnia species during the period of peak pollution by heavy metals and their replacement by exotics. Diapausing eggs of Daphnia pulicaria and D. ambigua are present in lake sediments prior to, and just after 1900, but are absent from the early part of this century until about 1990, when they reappear along with another local species, D. galeata mendotae. At the sediment depths (i.e., time period) that these species are absent, D. exilis and D. curvirostris diapausing eggs become abundant. Both species are native to geographical regions distant from Onondaga Lake? D. exilis is found naturally in shallow salt pools in the southwestern United States, and D. curvirostris is native to the Eurasian continent (although there is one report of its occurrence from shallow melt-water pools in the extreme northwest corner of Canada). The presence of D. exilis in Onondaga Lake was reported in previous annual reports and in the journal Limnology and Oceanography (see publications section below), but the presence of D. curvirostris is a new discovery of Year 3. The diapausing eggs of this species could not be identified morphologically and none of the eggs from the lake sediments could be induced to hatch. However, mtDNA was readily extractable from the eggs. We were able to amplify this product and then carry out restriction fragment length polymorphism (RFLP) and sequencing. Similar analyses for other taxa found, or previously reported to be present in the lake, permitted us to identify it unambiguously as D. curvirostris. It is likely that both exotic species invaded Onondaga Lake through transport on industrial equipment.
Both the native and the exotic Daphnia had marked effects on the lake ecosystem through their consumption of phytoplankton. The native species currently cause a marked "clear-water phase" during May of each year when they emerge from diapause (or grow from over-wintering stock) to eat down the spring algal bloom. During the 1960s and 1970s, when the exotic species were present, a clear-water phase also was present, but occurred much later in the summer due to a different seasonal phenology with maximum abundance in August for D. exilis. During the entire period of the 1980s, when no Daphnia were present, there was no clear-water phase in the lake.
Nelson Hairston spent his sabbatical leave during the fall of 1998 at the Max-Planck-Institute for Limnology (MPIL) in Plon, Germany. His research there was supported in part by a joint National Science Foundation-Deutscher Akademischer Austauschdienst (NSF-DAAD grant for cooperative research between Dr. Hairston's laboratory and that of Dr. Winfried Lampert, Director of the Institute. The NSF International Programs grant was funded in association with this EPA/NSF Water and Watersheds Program grant. The exchange was highly productive with students and postdoctoral associates traveling between the MPIL and Cornell University on multiple occasions. It was part of this work that resulted in a collaboration with Dr. Lawrence Weider at MPIL and the identification of D. curvirostris in Onondaga Lake (described above; see publications section below). The principal accomplishment during this period was the discovery that the diapausing eggs of Daphnia galeata could be hatched from different time periods in the past to trace their evolution to an enhanced ability to cope with cyanobacteria ("blue-green algae") in their diet brought on by lake eutrophication. The data also suggest that emergence of distinct genotypes from the egg bank may have influenced the way the population responded to a reduction in phosphorus inputs to the lake. This work was published earlier this year in the journal Nature (see publications section below).
Several other collaborations have come out of this project including manuscripts on: (1) the role of diapausing egg banks in the coexistence of competing copepod species in German lakes (with B. Santer of MPIL), (2) the record of fish introductions in high mountain lakes in Austria, and (3) the record of phosphorus inputs to Cayuga Lake.
A critical issue in understanding the role of egg banks in lake recovery from pollution is the effect of sediment processes in the return of buried eggs to the sediment surface. Two key factors in these dynamics are the rate of sediment deposition on top of eggs, and the extent of sediment mixing by benthic animals. In Onondaga Lake, sedimentation rates were extremely high (approximately 1 cm/yr) during the period of maximum industrial activity, and sediment mixing was either very limited or completely eliminated by toxic elements contained in the sediments and extensive periods of anoxia in the water overlying the sediments. In Oneida Lake, sedimentation rate is between one-quarter and one-half of that in Onondaga Lake, and benthic invertebrates are abundant. Sedimentation rate varies among sites across Oneida Lake, however, with highest rates near the mouth of a major tributary, and lower rates at a more central location on this very large (200 km2) lake. The factors controlling egg exposure to hatching cues are an important topic for further investigation.
Future Activities:
We obtained a 1-year, no-cost extension to this grant and so are now in the fourth year. The primary objectives for this added period have been to complete the incubation of diapausing eggs to determine their viability. In addition, we have been conducting metals analyses for an additional core from Onondaga Lake due to a need to cross reference our work with previously published results. We have begun in earnest the task of writing up our research for publication with several papers already out, and more either submitted or in preparation.Journal Articles on this Report : 9 Displayed | Download in RIS Format
Other project views: | All 20 publications | 10 publications in selected types | All 9 journal articles |
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Duffy MA, Perry LJ, Kearns CM, Weider LJ, Hairston NG. Paleogenetic evidence for a past invasion of Onondaga Lake, New York, by exotic Daphnia curvirostris using mtDNA from dormant eggs. Limnology and Oceanography 2000;45(6):1409-1414. |
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Ellner SP, Hairston NG, Kearns CM, Babai D. The roles of fluctuating selection and long-term diapause in microevolution of diapause timing in a freshwater copepod. Evolution 1999;53(1):111-122. |
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Hairston Jr. NG. Zooplankton egg banks as biotic reservoirs in changing environments. Limnology and Oceanography 1996;41(5):1087-1092. |
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Hairston Jr. NG, Bohonak AJ. Copepod reproductive strategies: life-history theory, phylogenetic pattern and invasion of inland waters. Journal of Marine Systems 1998;15(1-4):23-34. |
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Hairston Jr. NG, Perry LJ, Bohonak AJ, Fellows MQ, Kearns CM, Engstrom DR. Population biology of a failed invasion:paleolimnology of Daphnia exilis in upstate New York. Limnology and Oceanography 1999;44(3):477-486. |
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Hairston Jr. NG, Hansen A-M, Schaffner WR. The effect of diapause emergence on the seasonal dynamics of a zooplankton assemblage. Freshwater Biology 2000;45(2):133-145. |
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Hairston Jr. NG. Time travelers:what's timely in diapause research. Archiv für Hydrobiologie-Advances in Limnology 1998;52:1-15. |
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Hairston Jr. NG, Lampert W, Caceres CE, Holtmeier CL, Weider LJ, Gaedke U, Fischer JM, Fox JA, Post DM. Lake ecosystems: rapid evolution revealed by dormant eggs. Nature 1999;401(6752):446. |
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Santer B, Blohm-Sievers E, Caceres CE, Hairston Jr. NG. Life-history variation in the coexisting freshwater copepods Eudiaptomus gracilis and Eudiaptomus graciloides. Archiv für Hydrobiologie 2000;149(3):441-458. |
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Supplemental Keywords:
ecological effects, vulnerability, lake eutrophication, sensitive populations, genetic polymorphisms, chemicals, toxics, aquatic, remediation, cleanup, biology, ecology, genetics, limnology, zoology, northeast, New York, NY, EPA Region 2, industry., RFA, Scientific Discipline, Toxics, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Limnology, National Recommended Water Quality, Water & Watershed, Contaminated Sediments, exploratory research environmental biology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Chemical Mixtures - Environmental Exposure & Risk, Ecosystem Protection, Chemistry, State, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Biology, EPA Region, Mercury, Watersheds, Ecological Indicators, ecological exposure, aquatic, anthropogenic disturbances, freshwater ecosystems, contaminated sediment, restoration of lakes, mercury loading, zooplankton diapausing eggs, lakes, diapausing egg response, aquatic ecosystems, response and recovery of impacted lakes, lake sediment, aquatic ecology, Region 2, freshwater ecosystem, zooplankton, heavy metals, egg hatch rates, lake ecosystemsRelevant Websites:
http://www.es.cornell.edu/hairston/hairston.html
http://www.dnr.cornell.edu/facstf/mills.htm
http://www.dnr.cornell.edu/fieldst/cbfs.htm
http://www.mpil-ploen.mpg.de
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.