Depomod, Meramod, and Tropomod Models - ecasa

ECASA – Ecosystem Approach for Sustainable Aquaculture
DEPOMOD / MERAMOD / TROPOMOD models
What do these zone A models do?
They predict footprint of waste feed and faeces on sea bed
and associated benthic impact
Chris Cromey
SAMS, Oban,
Scotland
chjc@sams.ac.uk
Particles
Cage
Current
Sea bed

Summary of models and species/environment
Model Species Environment Authors/Project
DEPOMOD
(AUTODEPOMOD is
regulatory software)
Salmon North Atlantic Cromey, Nickell,
Black
MERAMOD
Sea Bass, Sea
Bream
Eastern
Mediterranean
Cromey et al.
EUFP5 project
(HCMR, IfM-
GEOMAR, Akvaplan)
TROPOMOD
(in progress)
Milkfish, Tilapia Philippines/Asia Cromey, Nickell,
Black, White
EU FP6 PHILMINAQ

Model Validation Current use and user
base
Shortcomings
Used in
regulation
?
DEPOMOD
(AutoDEPOMO
D is regulatory
software)
12 traps,
resuspension
tracer study, 40+
benthic sampling
stations
Other users have
validated also
Biomass consent of all
new and reapplications
in Scotland
All sea lice treatment
consents
100 + licenses issued in
14 countries
Validation
limited at high
dispersive
sites
Steep
bathymetry
V. coarse
sediments
YES
MERAMOD
129 traps
30+ benthic
sampling stations
Mostly EIA
10+ licenses issued
Needs more
use and
feedback from
users
NO, but
has
potential
use
TROPOMOD
(in progress)
30+ traps
Some benthic
fauna data, but
not much fauna
around
Developing
guidelines/recommendat
ions for rapidly
developing industry
More benthic
faunal data
Needs
coupling with
larger area
zone B model
Advisory/
planning
role

DEPOMOD model
Fish farm by SAMS

MERAMOD model
Agolikos fish farm
RV Philia and SAMS drifting buoys

Courtesy Akvaplan-niva
TROPOMOD model
An aquaculture hotspot in Taal Lake, Philippines

FLOW OF INFORMATION THROUGH MERAMOD
MERAMOD MODULES (I)
INPUT
INPUT
•CAGE POSITIONS
• CAGE POSITIONS
•STATION • POSITIONS
STATION POSITIONS
•BATHYMETRY
• BATHYMETRY
GRID GENERATION MODULE
GRID GENERATION MODULE
sea surface sea surface
INPUT
•FEED INPUT/SPECIES CAGE BY
CAGE; HYDROGRAPHIC DATA;
SETTLING VELOCITY DATA
•VARYING LEVELS OF
SCENARIO COMPLEXITY
WILD FISH MODULE
•Input pelagic/benthic feeding
effects by wild fish
PARTICLE TRACKING MODULE
•DIFFERENTIAL SETTLING OF PARTICLES
• ADVECTION OF PARTICLES BY CURRENTS
• REPRESENTATION OF CURRENT SHEAR
•TURBULENCE (RANDOM WALK)
water
column

MERAMOD MODULES (II)
INPUT
• VALIDATED RESUSPENSION
MODEL PARAMETERS
(e.g. critical resuspension, deposition
shear stress; erodibility constant)
water
column
FLUX/DEPOSITION MODULE
RESUSPENSION & CARBON DEGRADATION
• FLUX/DEPOSITION ON BED
• RESUSPENSION FROM BED
• CARBON DEGRADATION - G MODEL
• CARBON DEGRADATION - G MODEL
BENTHIC MODULE
BENTHIC MODULE • BENTHIC COMMUNITY
• BENTHIC COMMUNITY SUCCESSION SUCCESSION LINKED LINKED TO
QUANTITATIVE INPUTS OF
TO QUANTITATIVE INPUTS SOLIDS
OF SOLIDS
bed surface
underlying
sediment
layer
carbon/ solids
carbon/ accumulation solids
accumulation
g m -2 yr -1
g m -2 yr -1

Measurement of waste flux to the sea bed
Flux is grams of waste food and faeces depositing per m 2 sea bed
per day, measured with sediment traps

MERAMOD model validation – sediment
trap studies
Observed AFDW (g m -2 yr -1 )
10000
8000
6000
4000
2000
d)
y = 1.04x + 82
R 2 = 0.61
0
0 2000 4000 6000 8000 10000
Predicted AFDW (g m -2 yr -1 )

R 2 = 0.82
160
140
120
100
80
60
40
20
0
Species (no. m -2 )
SPECIES
100000
10000
1000
100
10
1
1000000
100000
10000
1000
100
R 2 = 0.52
10
1
100000
10000
1000
1000
Abundance (Ind. m -2 )
ABUNDANCE
MERAMOD model
validation – predicted
flux correlates with
ECASA indices
100
10
Biomass (g m -2 )
BIOMASS
1
100000 10000 1000 100 10 1
1
Modelled flux + 1 (g m -2 yr -1 )
MODELLED FLUX (g m -2 yr -1 )

TROPOMOD – advice to policy makers and
producers on cage spacing/feeding strategy, etc
Contour map of waste flux
N
-2 -1
grams solids m bed d
Benthic
community
75
Heavily impacted
(no animals)
14
Intermediate
(some effect)
1
Limit of benthic
impact
Scale
0 100 200 300 400 500 600

TROPOMOD - Bolinao Narrows – reduction in FCR (less feed
wastage) with single lines of cages results in intermediate
impact -Good
FCR = 2.8:1 FCR = 1.5:1
-2 -1
grams solids m bed d
N
75
14
1
Scale
0 100 200 300 400 500 600

Data requirements and cost
Data to run
model
Hydrographic
data
Bathymetry
Cage layout
specified
Cage
dimensions
Feed returns
so feed input
is known?
Accurate
position cages
Benthic fauna
monitoring
Farmer has to collect these data
as part of consent
15 days, 3 depths
Survey or chart
Yes
Yes
Yes, but always hard to get
information
Yes, from survey
Required
Cost of
running model
Depends

DEPOMOD / MERAMOD model user base