Table 2. Ecological model state variables, forcings, parameters, and functional relationships.

State Variables
Mussels: total tissue [kg of dry weight per meter of cultivated sock]
 
Functional Relationships
dMussels/dt=(NetGrowth*DenCoeff*PatternCoeff-Losses)*Mussels [1]
Forcings
  Tw: water temperature [°C]
POC: Particulate Organic Carbon [gC/m3]
PHYT: Phytoplanktonic carbon concentration [gC/m3]
OD: Organic Detritus [gCm3]
 
OD=POC-PHYT [2]
F=p1*PHYT+p2*OD [3]
p1=PHYT/(PHYT+OD) [4]
p2=OD/(PHYT+OD) [5]
Parameters
asPHYT: mussels assimilation efficiency of phytoplankton [-]
asDT: mussels assimilation efficiency of DT [-]
aM: maximum specific mussel growth rate [day-1]
kM: half saturation constant for mussel filtration [g/m3]
filt_rate: average filtration rate of mussels [m3/sec/g]
line_no the number of lines in the specific mussel farm establishment [-]
line_length: the length of the average cultivation line [m]
SC1: mussels of length <2cm
SC2: mussels of length >2cm
socksSC1: socks occupied by mussels of size class 1 [-]
socksSC2: socks occupied by mussels of size class 2 [-]
musSC1: dry weight of mussels of size class 1 [g/m of sock]
musSC2: dry weight of mussels of size class 2 [g/m of sock]
eM: excretion rate of mussels [day-1]
mM: mortality rate of mussels [day-1]
WD: Wind direction [°]
NetGrowth=asPHYT*{aM*[p1*PHYT/(kM+F)]+asDT*[p2*OD/(kM+F)]} [6]

Losses= eM+mM [7]
where mM=f(Tw) as

if Tw<25° C then the mortality rate mM =0.02*aM.
if 25° C<Tw<26° C then the mortality rate is mM=0.25* aM. [8]
if Tw>26° C then the mortality rate is mM=0.5* aM.

DenCoeff=Umean/Urequired [9]
Urequired=filt_rate*line_no*mussels/line_lenght [10]
mussels=musSC1*socksSC1*(1/3)+musSC2*socksSC2*(2/3) [11]

 

 

 PatternCoeff=f(WD) [12]