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3.3.3. Biological parameters
As with the chemical environmental parameters, subsamples for
meiobenthos were collected with a cylinder 28 mm in diameter and cut into
sections at the following locations:
JET 1, 2, 3 and 4: 0-0.25, 0.25-0.5, 0.5-0.75, 0.75-1.0, 1.0-2.0, 2.0-
3.0 cm.
The samples for sedimentary bacteria were collected by spoon from
the same layers. The former was fixed with 10% buffered formalin, and the
latter with 2% glutaraldehyde and stained with DAPI.
Macrobenthos samples were collected with a USNEL-type box corer,
on which a 15 by 15 cm vegematic-style frame had been mounted to divide
the sample into eight parts. The subsamples obtained were sliced into 0-1,
1-2, 2-3 and 3-5 cm segments, and fixed with 20% buffered formalin.
3.3.4. Size categories of benthic fauna
Benthic fauna were categorised for this study as follows.
?? Megabenthos: fauna identified by the video recorder;
?? Macrobenthos: fauna larger than 300 µm and smaller than
4000 µm;
?? Meiobenthos: fauna larger than 32 µm and smaller than 300
µm;
?? Sedimentary bacteria.
3.4. Impact evaluation
JET was designed to simulate some of the disturbance effects of
redeposition on the patterns of the benthic community and subsequent
succession. For this purpose, the relationship between redeposition
thickness and biological responses should be addressed.
The biological responses were monitored with the methods
described above. For redeposition thickness, the following approaches
were tried:
?? Video observation: conditions of sediment deposition;
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