The Shellfish Farm module has been developed to simulate flow fields around the mariculture rafts and the impact of cultivation practices on the growth and development of any species of shellfish.
This module can only be activated by checking on the Use box of the Shellfish Farm Options from the Biota tab of the Water Quality form as shown in Figure 1.

Figure 1. Activate Shellfish Farm Module.

When the user clicks the OK button (Figure 1), the Shellfish Farm sub-module will be added to the Modules on the Model Control. RMC on Shellfish Farm module sub-tab under the Modules tab, then click the Settings option to open Shellfish Farm form as shown in Figure 2 below (the Shellfish Farm form can also be accessed by clicking on the Modify button in Figure 1). In this form, first set the Number of Shellfish Species. The form has six other tabs below: Model Settings, Shellfish Species, Farm Settings, Initial Conditions, Harvest Time and Harvest Rate. Each tab has a range of parameters that may be configured as described in the following sections.

Figure 2. Shellfish Farm Settings.

Model Settings

In Model Settings it is necessary to check the Interact with Water Quality Module box to link the input data of water quality parameters (as shown in Figure 3) to the water quality module in EFDC.

Figure 3. Shellfish Farm Model Settings.

The interaction of the shellfish farm with water quality parameters depends on the number of water quality parameters simulated in the water quality module settings as shown in Figure 4. A value of 1 or 0 means that the parameter simulated or not simulated respectively.

Figure 4. Water Quality Parameters Simulation Settings.

Editing Species

In the Shellfish Farm form the user should identify the Number of Shellfish Species they want to add to the model and then define the characteristics of each species. Click on the Edit Species button to open the Shellfish Species form to set species characteristics.

Figure 5. Edit Shellfish Species.

In this form the user can set the name of the species to be simulated. The shellfish parameters should be based on the aquatic ecological characteristics of this species. These parameters can be defined by eight tabs (From  Figure 6 to Figure 13): General, Infiltration, Respiration, Growth, Mortality, Excretion, Spawning, Larvae. Refer to the EFDC+ Theory Guide to learn how these parameters impact the shellfish life cycle. The larvae characteristics are for information only at this stage and not user configurable.
When defining characteristics of the shellfish completed, the characteristics are also displayed on the Shellfish Species tab as shown in Figure 14.

Figure 6. Shellfish species characteristics : General.

Figure 7. Shellfish species characteristics: Infiltration.

Figure 8. Shellfish species characteristics: Respiration.

Figure 9. Shellfish species characteristics: Growth.

Figure 10. Shellfish species characteristics: Mortality.

Figure 11. Shellfish species characteristics: Excretion.

Figure 12. Shellfish species characteristics: Spawning.

Figure 13. Shellfish species characteristics: Larvae.

Shellfish Species

In the Shellfish Species tab, the shellfish parameters for each species are listed in the table.

Figure 14. Shellfish Species Tab.

Farm Settings

In the Farm Settings tab (Figure 15), the Number of Farming Zones should also be set. The corresponding number of farming groups will be created in the Shellfish Farming Zones table. A farming zone will have particular characteristics. Currently, the farm type and the depth at which the farm is set are not used. However, the species death rate should be set for the number of individuals that die in that zone per day.  

Figure 15. Farm Settings Tab.

Shellfish Initial Conditions

In the Initial Conditions tab assign the position and the initial number of individuals of the species as shown in Figure 16 below. 

• L, J, J columns: cell index of the shellfish farm
• Zone: Farm zone index
• IC# Species Name: Initial number of individuals

Figure 16. Shellfish Farm Initial Conditions.

Harvest Times

If shellfish harvesting to be simulated at certain time then this can be set in the Harvest tab. The Number of Harvests to be conducted during the simulation period should be entered. In the Harvest Settings form sets the mid-point of the harvest time of the shellfish as well as the minimum weight of shellfish that can be harvested in grams of carbon. The day of harvest is the model Julian time. For example, if the model run time starts at day 1 then day 200 is the midpoint of the shellfish is harvest, with the calculation effectively instantaneous. The harvest will occur on that day, but will only apply to individuals larger than the minimum size, smaller individuals will not be harvested.

Figure 17. Harvest Times Tab.

Harvest Rates

In the Harvest Rate, the user can set the day and the rate of harvesting. Click the Edit button in the Harvest column, and the form for Harvest Rate Setting will be displayed. 

Figure 18. Harvest Rates Tab.

In this form the user can set the day and harvest rate for this species in this cell as a proportion of the total number of individuals, with 0 meaning harvest, and 1 all individuals are harvested.

Figure 19. Harvest Rates Setting.

After completing these settings, click the OK button to save the settings, close the form and finish configuring the shellfish module.