Transcript Project Title: Improved and Sustainable Aquaculture in the

A. Y. KARIKARI & RUBY ASMAH
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Institutions involved:
• CSIR Water Research Institute
• Institute of Aquaculture, University of Stirling, UK.
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Duration of Project: 3 years (12/2012 to
12/2015)
Funding: Royal Society Leverhulme African
Award,
UK
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Water Research Institute
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Dr. Ruby Asmah
Dr. Joseph Ofori
Dr. Hederick Dankwa
Mr. Anthony Karikari (PhD student)
Institute of Aquaculture
◦ Prof Lindsay Ross
◦ Dr. Trevor Telfer
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Fish production from cage fish farming currently
accounts for more than 80% of aquaculture
production in Ghana (Fisheries Commission 2012
– unpublished data)
There are more than 58 individual fish farms
sited on the Lake with over 1700 cages (Fisheries
Commission 2010 – unpublished data)
Production capacities vary from small scale to
large commercial scales.
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The cages are largely
sited in Stratum II of
Lake Volta
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Cage culture has both positive and negative
impacts.
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It is a “cheap” source of
protein
Enhances food
security, health and
wellbeing of the people
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A major source of income
to riparian communities
Poverty alleviation
Community development
(eg access road, provision
of electric power, schools
etc)
Women processing fish –
charges a fee per weight
of fish
Fish fat extraction for
processing and sale
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Like
many
other
farming
activities,
aquaculture relies on the use of natural
resources such as land, water, seed and feed.
Its growth always involves:
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The expansion of cultivated areas,
Larger aquaculture farms,
Higher stocking densities
Increased use of feed resources
Wastes are generated as a result
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The fish farmers rely on the environment to
dissipate and assimilate the waste generated
The nature and extent of environmental
consequences of cage aquaculture are often
dictated by the attributes of:
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location (hydrology, current speed etc)
intensity of production
production practices
species cultured and
feed types used.
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Real and/or perceived impacts of cage culture systems on
the surrounding aquatic environment and ecosystem
include the following (Tacon and Halwatt (2007)):
o Nutrient enrichment in water column and bottom sediment
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High phytoplankton bloom
High NH3
High NO2
Low DO, high turbidity
◦ Increased risk of disease occurrence on cage reared fish
and the potential to transfer disease to natural fish
populations
◦ Increased risk of fish escapes and consequent
potential impacts on wild fish populations including
potential genetic, ecological and social impacts
◦ Increased community concerns regarding the use of
public shared inland waters for rearing fish
◦ Increased need for the establishment of adequate
governmental controls.
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To build capacity in environmental
monitoring and assessment and to formulate
a plan for improved and sustainable cage
aquaculture on the Volta lake
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To determine the impacts of cage culture
on water quality, bottom sediments and
benthic communities (ecology) of the Volta
Lake
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To build skills in environmental monitoring
and impact assessments
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To provide guidelines for sustained cage
aquaculture in the lake Volta
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3 Training workshops
• Year 1 – Environmental management for Sustainable
Cage Aquaculture
• Year 2 - Advanced Environmental Modelling
• Year 3 – Presentation of project activities and
findings
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Hydrographic data collection
Field sampling of water and sediments
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Laboratory Analyses of samples
Modeling
Training of MSc Students & 1 PhD student
Journal Publications
N
B U R K I N A
F A S O
11°00'N
7°00'N
10°00'N
T
G
D' I V OI R E
O
COTE
O
STUDY
AREA
National Fish
Farmers Brigade
6°30'N
West Africa
Lee Farm
LEGEND
6°00'N
Road
River
Lake
Sampling Point
SCALE
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10
20
30 km
0°00'
0°30'E
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Main Lake (Gorge Area)
Farm Name: Lee Farm
Location: Ajena
Species Cultured: Tilapia
Production Level: 64 Mt
No. of cages: 168
Average size of cages:
Broodstock (108) -4m x 4mx1.5m
Fry (5) – 4m x 4m x 1.5m
Fingerling (23) – 5m x 5m x 1.5m
Grow out (32) – 4m x 4m x 4m
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Main Lake
Farm: West Africa Fish (WAF)
Location: Asikuma
Years of Operation: 5
Species Cultured: Tilapia
Current Production: 2,300 Mt
No. of cages: 80
Circular cages 16m radius x 6m
Rectangular cages – 6mx6mx3m
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Hydrographic data
• Current velocity and direction
• Based on depth of water, data will be collected from
two to three depths
• Four field measurements in a year to cover both major
and minor wet and dry seasons
• Data collection will be at 20 - 30 mins interval
• Equipment - Drogue
• Bathymetry?
• Wind speed
•Water
Quality Measurements
• Bimonthly sample collection from all the sites
• WQ parameters include:
•pH, DO, Temperature, Conductivity, Turbidity, Nutrients,
Metals, COD, Transparency, Chlorophyll-a
•Sediment
Quality
• Bimonthly sampling
•Parameters – C, N, P, benthic communities, pH, H2S,
conductivity, redox potential, metals, particle size
analysis.
•Some
laboratory experiments
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Estimation of quantities of waste discharged
from fish cages to the Lake
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Mode of aquaculture waste dispersal and
identification of potential impact areas
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Interactions between aquaculture and the
environment and potential impacts on biota
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Improved capacity in environmental impact
assessment studies in relation to aquaculture
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New approaches and methods in
environmental monitoring and assessment
Better understanding of cage aquaculture and
its potential impacts on the lake
Optimization of site selection on the Lake
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Fish farm surveys
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2 Training Workshops ( 2013 and 2014)
•Environmental management for sustainable cage aquaculture development
•Ecosystem Approach to Aquaculture, Carrying Capacity and Environmental
Modelling
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Hydrology –
current velocity
and direction
using the drogue
and current
meter.
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Bathymetry
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Bimonthly
sampling of
water and
sediment
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A paper titled “Assessing the impacts of cage
fish farming on benthic communities in
sediments of Lake Volta” has been accepted
for oral presentation at the 15th World Lakes
Conference in Perugia Italy from 1st to 5th
September 2014.
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Continuation of Drogue measurements of
water current speed and direction at different
depth at WAF, Kpeve and Lee
Continue bi-monthly sampling of water and
sediment quality
Two more MPhil students to handle aspects
of the project (macroinvertebrates, drogue)
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At least one conference paper presentation
Completion of projects by current MPhil
students
Completion of two chapters by PhD student
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Distillation plant
Deioniser
Van Dorn Water sampler
Ekmans sediment grab
Filtration kits
Life jackets
DO – temperature probe
Sieves and shaker for particle size analysis
Echotest depth sounder
GPS devices etc.
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CSIR Water Research Institute (CSIR-WRI)
Environmental Protection agency (EPA)
Volta River Authority (VRA)
Water Resources Commission (WRC)
Ministry of Food and Agriculture (MOFA)
Fisheries Commission
Ghana Water Company (GWCL)
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Department of Fisheries and Watershed Mgt.
KNUST
Irrigation Development Authority (IDA)
Aquaculture Farmers
Fish Sellers
NGO’s