A PLAN FOR IMPROVED AND SUSTAINABLE CAGE AQUACULTURE IN LAKE

VOLTA

A. Y. KARIKARI & RUBY ASMAH

• Institutions involved:• CSIR Water Research Institute • Institute of Aquaculture, University of Stirling, UK.

• Duration of Project: 3 years (12/2012 to 12/2015)

• Funding: Royal Society Leverhulme African Award, UK

Project Information

Water Research Institute◦ Dr. Ruby Asmah◦ Dr. Joseph Ofori◦ Dr. Hederick Dankwa◦ Mr. Anthony Karikari (PhD student)

Institute of Aquaculture◦ Prof Lindsay Ross◦ Dr. Trevor Telfer

Project Team

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cage fish farming currently accounts for more than 80% of aquaculture production in Ghana (Fisheries Commission 2012 – unpublished data)

There are more than 58 individual fish farms sited on the Lake with over 1700 cages (Fisheries Commission 2010 – unpublished data)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.

Introduction/Background

Introduction (Cont’d) The cages are largely

sited in Stratum II of Lake Volta

Cage culture has both positive and negative impacts.

Impacts of Cage Aquaculture

Positive Impacts of cage aquaculture

It is a “cheap” source of protein

Enhances food security, health and wellbeing of the people

Positive Impacts of Cage Culture (Cont’d)

A major source of income to riparian communities

Poverty alleviation

Community development (eg access road, provision of electric power, schools etc)

Positive Impacts of Cage Culture (Cont’d)

Women processing fish –charges a fee per weight of fish

Fish fat extraction for processing and sale

Like many other farming activities, aquaculture relies on the use of natural resources such as land, water, seed and feed.

Its growth always involves:◦ The expansion of cultivated areas, ◦ Larger aquaculture farms, ◦ Higher stocking densities ◦ Increased use of feed resources

Wastes are generated as a result

Negative Impacts of cage aquaculture

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: ◦ location (hydrology, current speed etc)◦ intensity of production◦ production practices◦ species cultured and ◦ feed types used.

Negative Impacts of cage aquaculture (Cont’d)

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

- 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

Negative Impacts of cage aquaculture (Cont’d)

◦ 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.

Negative Impacts of cage aquaculture (Cont’d)

To build capacity in environmental monitoring and assessment and to formulate a plan for improved and sustainable cage aquaculture on the Volta lake

PROJECT AIM

• To determine the impacts of cage culture on water quality, bottom sediments and benthic communities (ecology) of the Volta Lake

• To build skills in environmental monitoring and impact assessments

• To provide guidelines for sustained cage aquaculture in the lake Volta

OBJECTIVES

• 3 Training workshops• Year 1 – Environmental management for

Sustainable Cage Aquaculture • Year 2 - Advanced Environmental Modelling• Year 3 – Presentation of project activities and

findings• Hydrographic data collection• Field sampling of water and sediments

Project Activities

• Laboratory Analyses of samples• Modeling• Training of MSc Students & 1 PhD student• Journal Publications

Project Activities

STUDY AREA

West Africa

Lee Farm

LEGEND

Road

River

Lake

Sampling Point

SCALE

0 10

6°00'N

20 30 km

0°00'

6°30'N

7°00'N

N

0°30'E

C O

T E

D'

I V

OI R

E

Farmers BrigadeNational Fish

AREASTUDY

10°00'N

11°00'N

B U R K I N A F A S O

T O G

O

STUDY AREA- LEE FARM 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

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

STUDY AREA- WEST AFRICA FISH

Kpeve

Storm at Kpeve

• 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

DATA COLLECTION

DATA COLLECTION•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

• Estimation of quantities of waste discharged from fish cages to the Lake

• Mode of aquaculture waste dispersal and identification of potential impact areas

• Interactions between aquaculture and the environment and potential impacts on biota

• Improved capacity in environmental impact

assessment studies in relation to aquaculture

PROJECT OUTCOMES

• 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

PROJECT OUTCOMES

Work Done So Far Fish farm surveys

Work Done So Far (Cont’d) 2 Training Workshops ( 2013 and 2014)

•Environmental management for sustainable cage aquaculture development•Ecosystem Approach to Aquaculture, Carrying Capacity and Environmental Modelling

Work Done So Far (Cont’d) Hydrology –

current velocity and direction using the drogue and current meter.

Work Done So Far (Cont’d) Bathymetry

Work Done So Far (Cont’d) Bimonthly

sampling of water and sediment

Work Done So Far (Cont’d) 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.

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)

Activities/Targets for This Year

At least one conference paper presentation

Completion of projects by current MPhil students

Completion of two chapters by PhD student

Activities/Targets for This Year

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.

Equipment Provided

• 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)

BENEFICIARIES

• Department of Fisheries and Watershed Mgt. KNUST

• Irrigation Development Authority (IDA)• Aquaculture Farmers• Fish Sellers• NGO’s

BENIFICIARIES

Preparing for Field work

THANK YOU