Mireille Consalvey PhD Thesis - University of St Andrews

Table 5.5: Sampling schedules in situ Eden
Sample
Number Time
5.3. Results
Day one
In sim inve"Outiorl into Fili(: ]-( hytobcrithic mjL-ratmii
. .... .....
Cumulative
time
1 10: 22 0
2 11: 25 63
3 12: 19 117
1
1
4 13: 14 172
5 14: 13
231
6 15: 15 293
7 16: 10 ,
Sample
348,
Number Time
5.3.1. Tagus Estuary (Portugal)
Light attenuation co-efficients (Tagus)
Dav three
Sample
Day two
Number Time Cumulative time
Cumulative
time
1 16: 16 0
2 17: 25 69
3 18: 16 120
4 19: 18 182
5 20: 16 240
6 21: 15 299
7 22: 00 344,
.
8 1 22: 23 3671
.
1 2: 34 0
2 3: 32 58
3 4: 30 116
4 5: 46 192
5 6: 45 251
6 7: 47 313
7 [
1
8: 24
350
The light attenuation co-efficients did not significantly vary between cores
(H = 7.11, df = 4, p=0.130) or with time (H = 6.73, df = 5, p=0.241). The mean
light attenuation co-efficient was 14.31 + 0.97 mm-1. By a depth of 322 ptin the
surface light had been attenuated by 99%. Figure 5.4. shows how PPFD changed
at the depths 100,200 and 300 pm over the course of the day.
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