Sediment Dynamics by Bioturbating Organisms
131
and Gardiner (1931) on a holothurian in the Maldive Islands. McGinitie
(1934) came to extremely high estimates of over 1 m sediment reworking per
year for a burrowing crustacean Callianassa californiensis in California.
Dapples (1938, 1942) summarised the work up to that period and informed
sedimentologists of the importance of bioturbation. Rhoads (Rhoads 1963,
1967,1974; Rhoads and Young 1970,1971) in particular was influential in the
upsurge of (quantitative) bioturbation research that has taken place since the
1960s.
The tidal flats of the Wadden Sea were the study object of German
researchers particularly after Richter had strongly advocated the foundation
of the institute "Senckenberg am Meer" in Wilhelmshaven (1928), an institute
especially for ''Aktuopalaontologie'' (Richter 1928) and the study of recent
sediments, actuogeology. Schafer (1962) gives an excellent review of his own
work carried out in the Wadden Sea and the North Sea and that of others in
Germany such as Wohlenberg (1937) on Sylt and Linke (1939) in the Jade
Bight. About 200 pages of his book deal with sediment disturbance by organisms in relation to their different activities (food gathering, hole- and tubebuilding, locomotion, resting and escape): a wealth of information timely
translated into English in 1972. This Senckenberg school of research of recent
sediments not only continued in the Wadden Sea and North Sea (e.g. Hertweck 1970, 1994), but also extended its area of research outside the North Sea,
often in co-operation with local institutes, to Italy (e. g. Reineck and Singh
1971), Georgia, USA (e.g. Howard and Reineck 1972), and Taiwan (e.g.
Reineck and Cheng 1978).A successful textbook by Reineck and Singh (1975)
further helped to propagate the knowledge gained.
Boudreau (1998), reviewing literature on tracer-identified mixed-layer
thickness of marine sediments - which is the combined effect of mixing by
bioturbation and physical processes - observed a world-wide mean value
(±SD) of 9.8±4.5 cm from the intertidal to the deep sea. For modellers this is
an interesting outcome, and we may ask why continue with bioturbation
studies: this mixing of sediments is for the large part due to bioturbation.
However, a search for recent literature using Current Contents (January 1997
to May 1999) and bioturbation as akeyword,gave some 100 papers,indicating
bioturbation research is still very much alive. Of these papers, some 70 % dealt
with bioturbation in marine environments, and some 50 % with the role of
bioturbation in mineralisation or burrowing and release of pollutants. Rate
measurements of bioturbation are still popular (25 %), the rest deal with
effects on sediment properties, biological interactions via bioturbation,
autecology of bioturbators, and modelling.
131
and Gardiner (1931) on a holothurian in the Maldive Islands. McGinitie
(1934) came to extremely high estimates of over 1 m sediment reworking per
year for a burrowing crustacean Callianassa californiensis in California.
Dapples (1938, 1942) summarised the work up to that period and informed
sedimentologists of the importance of bioturbation. Rhoads (Rhoads 1963,
1967,1974; Rhoads and Young 1970,1971) in particular was influential in the
upsurge of (quantitative) bioturbation research that has taken place since the
1960s.
The tidal flats of the Wadden Sea were the study object of German
researchers particularly after Richter had strongly advocated the foundation
of the institute "Senckenberg am Meer" in Wilhelmshaven (1928), an institute
especially for ''Aktuopalaontologie'' (Richter 1928) and the study of recent
sediments, actuogeology. Schafer (1962) gives an excellent review of his own
work carried out in the Wadden Sea and the North Sea and that of others in
Germany such as Wohlenberg (1937) on Sylt and Linke (1939) in the Jade
Bight. About 200 pages of his book deal with sediment disturbance by organisms in relation to their different activities (food gathering, hole- and tubebuilding, locomotion, resting and escape): a wealth of information timely
translated into English in 1972. This Senckenberg school of research of recent
sediments not only continued in the Wadden Sea and North Sea (e.g. Hertweck 1970, 1994), but also extended its area of research outside the North Sea,
often in co-operation with local institutes, to Italy (e. g. Reineck and Singh
1971), Georgia, USA (e.g. Howard and Reineck 1972), and Taiwan (e.g.
Reineck and Cheng 1978).A successful textbook by Reineck and Singh (1975)
further helped to propagate the knowledge gained.
Boudreau (1998), reviewing literature on tracer-identified mixed-layer
thickness of marine sediments - which is the combined effect of mixing by
bioturbation and physical processes - observed a world-wide mean value
(±SD) of 9.8±4.5 cm from the intertidal to the deep sea. For modellers this is
an interesting outcome, and we may ask why continue with bioturbation
studies: this mixing of sediments is for the large part due to bioturbation.
However, a search for recent literature using Current Contents (January 1997
to May 1999) and bioturbation as akeyword,gave some 100 papers,indicating
bioturbation research is still very much alive. Of these papers, some 70 % dealt
with bioturbation in marine environments, and some 50 % with the role of
bioturbation in mineralisation or burrowing and release of pollutants. Rate
measurements of bioturbation are still popular (25 %), the rest deal with
effects on sediment properties, biological interactions via bioturbation,
autecology of bioturbators, and modelling.