205
Remains of cladocerans have been useful in
interpreting past conditions of lakes for which
there are many examples (Birks and Birks 1980 ).
Goulden ( 1969b ) had pioneered the works related
to changes in species diversity and equitability of
chydorid communities. Such works could be
used to assess the stability and responses of the
communities to disturbances.
Summary
1. It had been a practice in the past to portray
alterations of aquatic ecosystems by changes
brought about in climatic conditions.
Remnants and records of these changes are
generally left in the sediments.
2. The prehistoric parameters are usually dealt
with by palaeolimnology, which is that branch
of limnological science which mainly deals
with the interpretation of sequences in the
sediments. Fossil records of sediments include
the biochemical substances produced by
organisms as well as morphological remnants
of specifi c organisms.
3. Many lakes of earlier glacial periods might
have been obliterated by succeeding glaciations, probably, due to fi lling up with sedimentary materials or by draining.
4. There are several methods to determine the
age of sedimented materials in lake deposits.
In postglacial lakes, the most signifi cant
method is, perhaps, to evaluate the age of
organic material by measuring its content of
radioactive carbon (
14
C). Much efforts have
been made in evaluating the accuracy of
14 C
dating of organic deposits.
5. Hematite possibly carries much of the
magnetic properties. Properties of magnetic
intensity and geomagnetic declination are
retained in the sediment as a remnant magnetism after sediments are deposited in a lake.
However, relatively coarse sediments are
brought to recipient lakes in glacial environments, with the infl ow of meltwater in the
spring and summer.
6. Many attempts have been made to use chemical constituents of the sediments variously in
order to interpret rates of limnological activities of lakes as well as changes in climate and
alteration of the drainage basin. The analysis
could be based on the assumption that the
chemical chronology could represent the
composite changes in inputs to the lake in
metabolic transformation which had occurred
within the lake. The problem of origin of
sedimentary organic constituents may be
addressed with regard to their chemical analysis. Further, the fossil pigments have, by far,
been perhaps the most promising organic
constituents of sedimentary stratigraphy,
which have been investigated in detail. A
general correlation between sedimentary
pigments and productivity has been demonstrated by a number of analyses on several
different types of lakes.
Suggested Readings
Birks HH (1980) Plant macrofossils in quaternary lake
sediments. Arch Hydrobiol Ergeb Limnol 15:1–60
Birks HJB, Birks HH (1980) Quaternary palaeoecology.
Edward Arnold Publications, London, pp 289
Brown SR (1968) Bacterial carotenoids from fresh water
sediments. Limnol Oceanogr 13:233–241
Cranwell PA (1976) Organic geochemistry of lake sediments. In: Nriagu JO (ed) Environmental biogeochemistry. I. Carbon, nitrogen. Phosphorus, sulfur and
selenium cycles. Ann Arbor Science Publications Inc,
Ann Arbor, pp 75–88
Creer KM, Thompson R, Molyneux L (1972) Geomagnetic
secular variation recorded in the stable magnetic remanence of recent sediments. Earth Planet Sci Lett
14:115–127
Daley RJ, Brown SR, McNeely RN (1977)
Chromatographic and SCDP measurements of fossils
phorbins and the postglacial history of little Round
Lake, Ontario. Limnol Oceaongr 22:349–360
Davis MB, Deevey ES Jr (1964) Pollen accumulation
rates: estimates from late- glacial sediment of Rogers
Lake. Science 145:1293–1295
Deevey ES, Rice DS, Rice PM, Vaughan HH, Brenner M,
Flannery MS (1979) Mayan urbanism: impact on a
tropical karst environment science 206:298–306
Frey DG (1974) Paleolimnology. Mitt Int Ver Limnol
20-95-123
Frey DG (1976) Interpretation of quaternary paleoecology from Cladocera and midges, and prognosis
regarding usability of other organisms. Can J Zool
54:2208–2226
Griffi ths M (1978) Specifi c blue-green algal carotenoids sediments of Esthwaite water. Limnol Oceanogr 23:777–784
Grootes PM (1978) Carbon-14 times scale extended:
comparison of chronologies. Science 200:11–21
Goulden CE (1969a) Interpretative studies of cladocerans
microfossils in lake sediments. Mitt Int Ver Limnol
17:43–55
Suggested Readings
Remains of cladocerans have been useful in
interpreting past conditions of lakes for which
there are many examples (Birks and Birks 1980 ).
Goulden ( 1969b ) had pioneered the works related
to changes in species diversity and equitability of
chydorid communities. Such works could be
used to assess the stability and responses of the
communities to disturbances.
Summary
1. It had been a practice in the past to portray
alterations of aquatic ecosystems by changes
brought about in climatic conditions.
Remnants and records of these changes are
generally left in the sediments.
2. The prehistoric parameters are usually dealt
with by palaeolimnology, which is that branch
of limnological science which mainly deals
with the interpretation of sequences in the
sediments. Fossil records of sediments include
the biochemical substances produced by
organisms as well as morphological remnants
of specifi c organisms.
3. Many lakes of earlier glacial periods might
have been obliterated by succeeding glaciations, probably, due to fi lling up with sedimentary materials or by draining.
4. There are several methods to determine the
age of sedimented materials in lake deposits.
In postglacial lakes, the most signifi cant
method is, perhaps, to evaluate the age of
organic material by measuring its content of
radioactive carbon (
14
C). Much efforts have
been made in evaluating the accuracy of
14 C
dating of organic deposits.
5. Hematite possibly carries much of the
magnetic properties. Properties of magnetic
intensity and geomagnetic declination are
retained in the sediment as a remnant magnetism after sediments are deposited in a lake.
However, relatively coarse sediments are
brought to recipient lakes in glacial environments, with the infl ow of meltwater in the
spring and summer.
6. Many attempts have been made to use chemical constituents of the sediments variously in
order to interpret rates of limnological activities of lakes as well as changes in climate and
alteration of the drainage basin. The analysis
could be based on the assumption that the
chemical chronology could represent the
composite changes in inputs to the lake in
metabolic transformation which had occurred
within the lake. The problem of origin of
sedimentary organic constituents may be
addressed with regard to their chemical analysis. Further, the fossil pigments have, by far,
been perhaps the most promising organic
constituents of sedimentary stratigraphy,
which have been investigated in detail. A
general correlation between sedimentary
pigments and productivity has been demonstrated by a number of analyses on several
different types of lakes.
Suggested Readings
Birks HH (1980) Plant macrofossils in quaternary lake
sediments. Arch Hydrobiol Ergeb Limnol 15:1–60
Birks HJB, Birks HH (1980) Quaternary palaeoecology.
Edward Arnold Publications, London, pp 289
Brown SR (1968) Bacterial carotenoids from fresh water
sediments. Limnol Oceanogr 13:233–241
Cranwell PA (1976) Organic geochemistry of lake sediments. In: Nriagu JO (ed) Environmental biogeochemistry. I. Carbon, nitrogen. Phosphorus, sulfur and
selenium cycles. Ann Arbor Science Publications Inc,
Ann Arbor, pp 75–88
Creer KM, Thompson R, Molyneux L (1972) Geomagnetic
secular variation recorded in the stable magnetic remanence of recent sediments. Earth Planet Sci Lett
14:115–127
Daley RJ, Brown SR, McNeely RN (1977)
Chromatographic and SCDP measurements of fossils
phorbins and the postglacial history of little Round
Lake, Ontario. Limnol Oceaongr 22:349–360
Davis MB, Deevey ES Jr (1964) Pollen accumulation
rates: estimates from late- glacial sediment of Rogers
Lake. Science 145:1293–1295
Deevey ES, Rice DS, Rice PM, Vaughan HH, Brenner M,
Flannery MS (1979) Mayan urbanism: impact on a
tropical karst environment science 206:298–306
Frey DG (1974) Paleolimnology. Mitt Int Ver Limnol
20-95-123
Frey DG (1976) Interpretation of quaternary paleoecology from Cladocera and midges, and prognosis
regarding usability of other organisms. Can J Zool
54:2208–2226
Griffi ths M (1978) Specifi c blue-green algal carotenoids sediments of Esthwaite water. Limnol Oceanogr 23:777–784
Grootes PM (1978) Carbon-14 times scale extended:
comparison of chronologies. Science 200:11–21
Goulden CE (1969a) Interpretative studies of cladocerans
microfossils in lake sediments. Mitt Int Ver Limnol
17:43–55
Suggested Readings