A. Changes in the Adirondack Lakes
•80% of lakes have acidified
since pre-industrial times
•Began acidifying between
1900 and 1950
•Even naturally acidic lakes
acidified further
•30-40% of lakes have
eutrophied
•Strong increase in salinity
in 30% of the lakes
B. Changes in Daphnia performance pre- and
post-eutrophication in European lake; potential for 'resurrection
ecology'
C. Onondaga Lake
•Described as the most
polluted lake in the United States
•Rapidly flushed (3.9
flushes/year)
•Large inputs of domestic
and industrial wastes
•Salt springs on east side
of the lake – manufacturing began in 1794, peaked in 1862, persisted
until 1920 – bulk of US salt supply around 1800
•1822 cut a channel to
permit lake’s surface elevation to drop to that of the Seneca River
(Erie and Barge canal system)
•Soda ash production (Solvay
Process) in 1884; later Allied Chemical Co. and then Allied Signal
•Successful salmonid fishery
in 1870’s and 1880’s; resorts on the shoreline. Fishery and
resorts gone by 1890’s.
•Swimming banned in 1920
•1951 began trying to reduce
discharge of mercury to the lake from the soda ash facility; fishing
banned due to mercury contamination
(angling allowed again in 1986, but fish are not to be eaten).
•1994 – sediments,
tributaries and some shoreline designated a superfund site
•Not only soda ash (Na2CO3),
but also 30 other chemicals were produced at the plant from 1884-1986.
•Until 1900 waste was
discharged directly into the lake; then it was put into waste beds
•About 30% of the lake shore
is wastebeds (2,000 acres; 8.1 km2), some 21 m high – not
lined
•Mercury from chlor-alkali
process dumped into the lake from 1946-1986 – 10 kg/d
•Benzene production –
hydrocarbons of benzene origin in the sediments
•First scientific studies in
1960’s
•Upstate Freshwater
Institute: www.ourlake.org, www.upstatefreshwater.org
•Paleolimnological studies
to look at changes in the lake – debates over historical changes in
nutrients, pollution, salinity…
Daphnia exilis
'resurrection ecology'
•Range expansion of 1,000 km
•Present in Onondaga Lake
from mid-1920’s and mid-1980’s
•Only most recent eggs still
hatch (mercury?)
•May have done well in the
lake due to higher salinity and low fish abundance; declined as fish
returned
•Genetic analysis suggests
that population may have started from one or a few individuals
(hypothesize that were transported
on
boots or equipment from a plant in Missouri)
Current conditions and debate
over lake remediation plans