CLAWS – Chemicals for Lice and Waste from Salmon Farms - is a repository of
particle-based models for application in salmon farms in semi-enclosed sea lochs and open sea areas. CLAWS is written in Python and consists of six modules:
1) Hydrodynamics.
2) Bath treatments.
3) Nutrients.
4) Waste.
5) E. coli.
6) Oyster larvae.
A more detailed description of each module, together with example applications, is provided in the Documentation section but may be summarised as follows:
1. Hydrodynamics - Python scripts have been written to allow the user to compare directly modelled and observed data. These data are output in a suitable format to assess how the model data compares against the calibration/validation requirements for hydrodynamic and discharge modelling e.g. the SEPA requirements.
2. Bath treatments - The bath treatment model predicts pesticide dispersion in the marine environment and comparison is made against statutory standards e.g. the SEPA standards for Maximum Allowable Concentration (MAC) and Environmental Quality Standard (EQS). The module can also be used for effluent dispersion.
3. Nutrients - This module calculates the sea area, mean height, volume and flushing time prior to deriving an equilibrium concentration enhancement (ECE) index for soluble nitrogen.
4. Waste - The waste model calculates the flux of particulate organic matter emanating from the salmon farm and its impact on the benthic community. Predictions of the fate of waste material (feed and faeces) for key parameters such as the footprint of the deposition on the sea floor and waste density levels.
5. E. coli - Dispersion and fate of Escherichia coli (E. coli) from raw sewage combined sewer overflows, agricultural run-off and other sources in rivers and estuaries.
6. Oyster larvae - Model for the transport and deposition of oyster larvae with multiple biological stages and active swimming behaviour.
CLAWS - Hydrodynamics
Current speed versus direction for the hydrodynamic model near Little Colonsay. Data is for the period of 80 days from the 4th July - 20th September 2021. [PDF→]
CLAWS - Hydrodynamics
Current speed percentile data for the hydrodynamic model. Data is near Little Colonsay for the period of 80 days from the 4th July - 20th September 2021. [PDF→]
CLAWS - Bath Treatments
Zoomed view of original Telemac 3D hydrodynamics mesh and reduced size model used for the pesticide dispersion. [PDF→]
CLAWS - Bath Treatments
Locations of virtual probes to measure Azamethiphos concentrations across the inner seas around Little Colonsay. Half-life of Azamethiphos = 8.9 days. [PDF→]
CLAWS - Bath Treatments
Snapshots of Azamethiphos dispersion in the Little Colonsay system. Half-life of Azamethiphos = 8.9 days. [PDF→]
CLAWS - Bath Treatments
Plot of area (km2) exceeding the SEPA EQS (40 ng/L) for Azamethiphos. The SEPA requirements state that this area must not exceed 0.5 km2. Half-life of Azamethiphos = 8.9 days. [PDF→]
CLAWS - Bath Treatments
Plot of area exceeding the SEPA MAC (100 ng/L) for Azamethiphos. The SEPA requirements state that this area must not exceed 0.5 km2. Half-life of Azamethiphos = 8.9 days. [PDF→]
CLAWS - Bath Treatments
Peak Azamethiphos concentration anywhere on the 20 m × 20 m × 3 m sampling grid. Half-life of Azamethiphos = 8.9 days. [PDF→]
CLAWS - Nutrients
Random initial particle generation within the bounds of the json control area in CLAWS. [PDF→]
CLAWS - Nutrients
Tidal range (m) graph at the proposed farm location for the period 2nd - 19th May 2018. [PDF→]
CLAWS - Waste
Waste solids mean deposition footprint for the proposed farm at Little Colonsay. Values correspond to the average sea bed deposition over 90-days from 1st March - 31st May 2019. [PDF→]
CLAWS - Waste
Footprint area of particulate organic carbon for the proposed farm at Little Colonsay. Values correspond to the average sea bed deposition over 90-days from 1st March - 31st May 2019. [PDF→]
CLAWS - Waste
Solids mean resuspension-to-deposition ratio for the proposed farm at Little Colonsay. Values correspond to the average over 90-days from 1st March - 31st May 2019. [PDF→]
CLAWS aims at developing the necessary computational tools to allow practitioners to model the dispersion of bath treatment chemicals, feed and faeces waste, and nutrients from aquaculture sites such as salmon farms. If you would like to contribute or need support in the form of consulting services, please get in touch.