12.2. Model Structure
237
TABLE 12.3. Urchin Growth Rates (Based on Estes and Duggins 1995 . For the purposes of the model, the growth rates for cohorts 41-45 and 66-70 were substituted
for the unknown growth rates of cohorts 51-55 and 56-60, respectively. All urch ins
with a test diameter above 60mm are assumed to die.)
TestSize Range
(mm)
0-5
6-10
11-15
16-20
21-25
26-30
31-35
36-40
41-45
46-50
51-55
56-60
61-65
66-70
Diameter Growth
(mm/yr)
5.41
4.39
6.39
6.72
5.02
5.25
3.40
2.43
1.93
0.95
N/A
N/A
N/A
2.48
Diameter Growth
(rnm/rnonth)
0.451
0.366
0.533
0.560
0.418
0.438
0.283
0.203
0.161
0.079
N/A
N/A
N/A
0.207
Time in Cohort
(months/Smm)
11.091
13.667
9.390
8.929
11.952
11.429
17.647
24.691
31.088
63.158
N/A
N/A
N/ A
24.194
.
. Standing Kelp Biomass
Biomass Accumulation
Drift Kelp Biomass
Drift Kelp Exits System
Drift Graze
Total Kelp Biomass
FIGURE 12.4