AG:GCP/GHA/026/EEC Terminal Report FAO/GOVERNMENT COOPERATIVE PROGRAMME INTEGRATED CONTROL OF AQUATIC WEEDS
|
AG:GCP/GHA/026/EEC Terminal Report FAO/GOVERNMENT COOPERATIVE PROGRAMME INTEGRATED CONTROL OF AQUATIC WEEDS
|
2.1 STRENGTHENING LOCAL EXPERTISE IN WEED CONTROL
2.3 MANAGEMENT OF AQUATIC WEEDS
2.4 IMPACT OF WEED INFESTATION ON FISH STOCKS
EPA - Environmental Protection Agency
EU - European Union
GWSC - Ghana Water and Sewerage Corporation
IAB - Institute of Aquatic Biology
IDA - Irrigation Development Authority
NPC - National Project Coordinator
NWHCC - National Water Hyacinth Control Committee
VRA - Volta River Authority
WRRI - Water Resources Research Institute
1.1 PROJECT BACKGROUND
Aquatic weeds are a hazard in water bodies in Ghana, affecting fisheries, aquaculture activities, navigation, drainage, irrigation, water supply schemes and power generating schemes. In urban centres human health is at risk from flooding, the accumulation of waste and the obstruction of free water flow in drainage systems which increases breeding habitats for vectors of human and animal diseases. Thick mats of aquatic weeds cause depletion of dissolved oxygen, reducing fish and wildlife populations. The coastal and riverine communities in Ghana depend on inland water for animal protein, irrigated crop production and fresh water supply. Inland waters also play an important role in rural transport. In Ghana some 20% of animal protein consumption comes from inland fisheries.
It is therefore important to control any weeds that affect the water supply, cleanliness and freedom of movement. The target beneficiaries are the people and communities directly and indirectly affected by problems created by aquatic weeds. West African inland waters were invaded by water hyacinth (Eichhornia crassipes) in the early 1980s. Awareness by scientists in Ghana of the problems associated with, and caused by, aquatic weeds, especially water hyacinth, led the Government of Ghana to initiate research on controlling their proliferation and to launch public awareness campaigns on the subject.
The first reports documenting the presence of water hyacinth in lagoons and other water systems in and around Accra, Ghana, were published at the end of 1984. The environmental and socio-economic effects of aquatic weeds were investigated by the Council for Scientific and Industrial Research, Ghana. In 1987, the Ghana National Water Hyacinth Eradication Committee was established. This later became the National Water Hyacinth Control Committee (NWHCC) under the Environmental Protection Agency (EPA). Through this committee, water hyacinth was first recorded in the Tano lagoon in the middle of 1990.
The Project Document for GCP/GHA/026/EEC, "Integrated Control of Aquatic Weeds in Ghana", was signed by the Government of Ghana, FAO and the European Union (EU) in June 1994. FAO was designated the donor agency's executing agency. The NWHCC, coordinated by the EPA, was designated the government counterpart institution responsible for project implementation.
The project was scheduled to last two years. Owing to administrative and technical delays the project did not take off until January 1995. As a result, the original termination date was at first extended to December 1996 and then to June 1997.
The EU contribution amounted to $US 542 365. The contribution of the Government of Ghana to the project included the provision of an enabling policy framework for aquatic weed control; participation in project operations; the establishment of institutional arrangements (coordinating committees/bodies); the provision of office space to house the project and basic facilities such as telephones, electricity and water; the exemption of customs duties and importation fees for materials, equipment and supplies purchased by FAO and the provision of rights and privileges to international staff on the project.
The Government of Ghana has put in place policy and legislative frameworks to deter the handling, use and trade in aquatic weeds, especially water hyacinth, which is strictly prohibited by law. There are a number of state agencies with responsibility for the management of water resources. These include the Institute of Aquatic Biology, now the Water Resources Research Institute (WRRI), the Wildlife Department of Ghana, the Irrigation Development Authority (IDA), the Ghana Water and Sewerage Corporation (GWSC), the Volta River Authority (VRA) and the EPA. Ghana's NWHCC assisted the project by providing the needed political and technical support and direction and reviewing the progress of the project. The Government of Ghana serviced the NWHCC meetings.
The National Biological Control Committee, coordinated by the Plant Protection and Regulatory Services Department of the Ministry of Food and Agriculture, gave useful technical assistance in the importation, rearing and release into the habitat of the natural enemies of aquatic weeds.
The project's objectives were to assist the Ghana NWHCC in creating awareness of the problem and preventing the spread of aquatic weeds to unaffected areas, and to coordinate aquatic weed management and research activities in Ghana. It also aimed to assist in the generation of appropriate technologies and the development of sustainable programmes for aquatic weed management in Ghana. The project's immediate objective was to focus on strengthening capabilities for rearing, releasing and monitoring biological control agents. Longer-term objectives were to launch a public education and awareness campaign and recruit and train field assistants.
A number of local and foreign institutions as well as private consultants gave technical and operational support to the project. These included the Department of Zoology at the University of Ghana; the VRA; the Agricultural Research Council; the Plant Protection Research Institute, South Africa; the International Institute of Tropical Agriculture, Ibadan, Nigeria; the Council for Scientific and Industrial Research Organisation, Division of Entomology, Australia; and the Technical Committee on Pesticides of the EPA.
Backstopping was provided in the approval for herbicide importation and use; training in herbicide application; construction and maintenance of insect-rearing units; delivery and rearing of biological agents from South Africa; training of front-line staff (monitoring staff at a community level); assessment of impacts of weed infestation on fish stocks; assessment of physical and chemical parameters in weed-infested water systems; translation of posters on salvinia and water hyacinth into five major languages spoken in Ghana; production of a video documentary on aquatic weed spread and control in Ghana; data collection, storage and retrieval; raising public awareness and, finally, the control (especially biological control) of aquatic weed.
International consultancies and inputs included technical consultancy services to the project on the biological control of aquatic weeds, the rearing of bioagents and the assessment of weed-spread, reviewing project progress and making recommendations for improving the biological control aspects of project implementation; technical expertise on the development and extension of new procedures to restore affected fish populations in weed infested water systems; a visit to Ghana to backstop and review technical aspects and the progress of project implementation; and, finally, useful technical recommendations through the preparation of a full evaluation mission report.
In order to more effectively maintain rearing units, release bioagents and monitor the efficiency of natural enemies introduced into the ecosystem, training was given to the National Project Coordinator (NPC) and other collaborators. Two technicians and a coxswain to oversee implementation of these activities on the Tano/Abbey/Ehy lagoon received training at the University of Ghana and Jewi wharf, respectively. In addition, a technician from the Department of Zoology at the University of Ghana received extensive training in quarantine, rearing and management of bioagents.
The NPC also attended the Expert Consultation on the Strategies for Water Hyacinth Control in Fort Lauderdale, Florida, the USA. The outputs included suitable guidelines for water hyacinth control in developing countries of the tropical and sub-tropical regions, and an updated status report on the biological control of water hyacinth.
Personnel from the EPA, the WRRI, the VRA, the GWSC and the IDA were educated on various aspects of the management of aquatic weeds.
The most significant aquatic weeds identified under the current surveillance system were water hyacinth (Eichhornia crassipes, origin: South America); salvinia (Salvinia molesta: South America); water lettuce (Pistia stratiotes: indigenous); coontail (Ceratophyllum demersum: cosmopolitan); hippo grass (Vossia cuspidata: indigenous); eel grass (Vallisneria gigantea: Australia) and Limnocharis flava: Asian.
Rivers, lagoons, lakes and reservoirs were surveyed countrywide for the presence of aquatic weeds. Water hyacinth was found in the Tano lagoon and 20 km upstream on the Tano River at Adife near Takinta. This was the furthest upstream it was recorded. The Customs, Excise and Preventive Services personnel at Alende were alerted to look out for any water hyacinth sightings. Around Accra, the Odaw River presented a small infestation of hyacinth infestations were sprayed earlier and later washed out to sea.
Beyond the borders of Ghana, water hyacinth was found in the Mou River, Burkina Faso. This infestation could eventually pose a serious threat to the Black Volta (of which the Mou is a tributary) and hence to Lake Volta. The C�te d'Ivoire side of the Tano lagoon and river also contained water hyacinth. Water lettuce was found throughout the country and is a problem especially around Kumasi, Kpong Headpond and Tano lagoon. In the Tano/Abbey lagoon complex and the Volta River and lake system, hippo grass growing along the edges of the water was found to have increased alarmingly over the past decade. In some areas it has formed large floating islands that interfere with water transport and fishing.
Copies of warning posters on water hyacinth, salvinia and water lettuce were distributed to all District and Metropolitan Assemblies, EPA Regional Offices, District Education offices, offices and substations of IDA, GWSC, the Fisheries Department of the Ministry of Food and Agriculture, universities, individuals and other groups. Warning posters of salvinia and water hyacinth translated by the Ghana Bureau of Languages into five major Ghanaian languages, namely Akan (Twi), Ga, Ewe, Nzema and Dagban, were printed and distributed. The newspapers, radio and television have been used extensively to inform the public on the dangers of handling, using and trading in aquatic weeds as well as on the possible options for controlling emerging aquatic weed problems. In addition, various public discussion meetings have been organized for district assemblies and relevant institutions countrywide as part of the public education and awareness creation campaign.
A video documentary on integrated aquatic weed control was made. Copies were given to the authorities in C�te d'Ivoire, Burkina Faso, Mali and Senegal to help them with their aquatic weeds management efforts. An unedited video documentary on water hyacinth infestation in Burkina Faso was made. A slightly edited version was sent to Burkina Faso for use in their public education and awareness-creation efforts.
A physical barrier constructed with bamboo and raffia palm was constructed by the project team to stop floating weeds from entering the wharf at Jewi. Having stood firm against sudds of hippo grass and water hyacinth at the onset of the rainy season, it collapsed in a storm. A number of similar physical barriers were erected at points within the Tano/Abbey/Ehy lagoon complex, notably at Asukro, Nyamebekyere, Ahonlezo and Bolenwo. These at least keep the entrances to the villages free of weeds. There were no such erections on the Tano river upstream.
A local WHCC was established at Jewi wharf to assist in the implementation of the project, particularly in the mobilization of local community members in the physical (manual) removal of water weeds.
The Kpong Headpond is the main supplier of water to parts of Accra and to a 3 500 ha irrigation scheme. Through consultations with the NPC, the VRA manually cleared 50 acres of sudds at a cost of $US 1 500 per acre. Maintenance clearing is still being carried out at about $US 800 per acre.
The herbicide, glyphosate, was cleared for use against aquatic weeds in Ghana. Successful trials were carried out. Some water hyacinth-infested portions of the Odaw stream were sprayed with glyphosate using a motorized sprayer. Over 90% treatment success was achieved two weeks after application. Using knapsacks, the approved herbicide was used to control water hyacinth infestations in the Kpeshie drain, some tributaries of the Odaw stream and a drain in Tema. No re-emergence of water hyacinth was observed more than a year after the treatment. Large-scale spraying of hippo grass infestations in the Tano/Abbey/Ehy lagoon complex could not be accomplished because of the project's delay in providing riverine communities in the Tano/Abbey/Ehy lagoon with environmental education on the implications of herbicidal applications, and because the project lacked funds for the January to June 1997 period.
An insectarium/quarantine facility was set up at the Department of Zoology at the University of Ghana. Imported biological control agents were initially quarantined and reared in this facility. In addition, 12 field rearing tanks were constructed in the first quarter of 1996: three tanks were installed at Jewi wharf, four at Asukro and three at Nyamebekyere, all in the Tano/Abbey/Ehy lagoon complex. Two others were constructed at Kpong in the Kpong Headpond.
The implementation of biological control of water hyacinth began in March 1994, after imported beneficial insects passed the obligatory quarantine period. An initial release of weevils (520 N. bruchi and 900 N. eichhorniae) was made between March and April 1994 in the Tano/Abbey/Ehy lagoon complex. Subsequent releases of weevils collected from both the facility at the University of Ghana and the rearing units in the Tano/Abbey/Ehy lagoon complex were carried out on a near-monthly basis.
On-the-spot checks at various locations throughout the lagoon complex showed that over 75% of the water hyacinth plants bore weevil feeding marks. Actual recoveries of adult Neochetina weevils from infected plants showed an average of 1 weevil per plant and a range of 0-6 weevils per plant. The ratio of N. bruchi to N. Eichhornia was 3:1.
The Neochetina weevils were well established both in the 20 km of water hyacinth-infested Tano river and the Tano/Abbey/Ehy lagoon complex. This was true for both the Ghanaian and the Ivorian sides of the lagoon complex.
The second bioagent for water hyacinth, the moth Sameodes albiguttalis, was introduced from South Africa in April 1996. The larvae were first quarantined and reared in the University of Ghana facility, but the first colony did not survive. A new consignment was reared at the insectarium. An unknown number of larvae was released in the Miller's wharf area in July 1996 and in the Nveye lagoon in December 1996. Field recoveries of the larvae or adult moth have not yet been obtained.
2.3.4.2 Kariba weed/salvinia
Initial rearing of the bioagent, Cyrtobagous salviniae received from South Africa in February 1996 was carried out in the facility at the University of Ghana. Between March and May 1996, three releases (about 650 individuals) of the salvinia-eating insect were made at Asukro in the Tano/Abbey/Ehy lagoon complex. The salvinia was quickly dispersed by winds, water flow and the constant movement of water hyacinth and so survival could not be assessed. In May 1996, 180 Cyrtobagous individuals were released onto the salvinia in a 5 ft2 quadrat through a PVC pipe with a 3 in diameter in the Miller's wharf area of the Nveye lagoon. From this quadrat and rearing tanks at Jewi wharf, releases of Cyrtobagous-infested salvinia plants were made in July, August, November and December 1996 at Nyamebekyere, Asukro and Miller's wharf. Marked suppression of salvinia infestation resulted some three months after these releases. At Nyamebekyere, in particular, only primary stages of salvinia plants could be seen three months after the releases. At Asukro and Miller's wharf, over 90% of salvinia plants showed apical bud damage by Cyrtobagous and signs of death.
2.3.4.3 Water lettuce
The water lettuce weevil, Neohydronomus affinis, was first introduced to Ghana from South Africa in November 1995. This colony, which was held in the insectarium at the University of Ghana, died out during the 1995 Christmas period. A second shipment was received in February 1996. They were quarantined and reared in the same facility. Fifty-four individuals were released onto water lettuce at Kpong Headpond in May 1996; 38 at Barekese reservoir, Kumasi, also in May 1996, and 60 in the Awutu Prison Camp Dam in October 1996. The latter site also served as a field breeding site for the water lettuce weevil. Some 150 individuals were released in the Tano river and lagoon complex in November 1996. Signs of insect activity, such as the larvae's mining tunnels were observed on water lettuce at the Barekese reservoir, Tano river and lagoon complex and Awutu Prison Camp Dam release sites, respectively. Water lettuce-infestation at the Kpong Headpond was virtually eliminated about two months later. However, there was no firm evidence to attribute this solely to the effect of Neohydronomus.
Monthly assessments of the impact of bioagents on aquatic weeds were conducted by a team coordinated by the NPC, whenever weather conditions were favourable for cruising on the lagoon.
The outputs were not fully achieved because the Institute of Aquatic Biology (IAB), responsible for the assessment of the impact of weed infestation on fish stocks, was unable to commence its assignment in 1995. IAB conducted a field assessment only in the two wet seasons (March and August) of 1996. In spite of some technical difficulties, the NPC was able to convince the IAB to carry out two dry season assessments to complete the picture. The final report on fish stock assessments for the four seasonal replications was in preparation at the time this report was written.
The Project Steering Committee met at the beginning and end of each project year to discuss project progress and results and also to give directions on the way specific outputs could be achieved. In addition, it called for emergency meetings whenever necessary. Annual, half-yearly and mission reports were discussed at these meetings.
The Information Services Department of the Ministry of Information was very influential in the project's public education and awareness raising drive.
Within two and a half years, a solid infrastructure for the integrated control of aquatic weeds in Ghana was put in place. A successful awareness campaign was launched and sustained, the further spread of water hyacinth was prevented, and natural enemies for water hyacinth, water lettuce and salvinia were introduced and established. Manual and chemical controls were effected with varying degrees of success. Recruitment and training of field assistants were carried out.
The average number of water hyacinth weevils per plant increased from 0 to 1 (variance 0-6) two and a half years after initial release in the Tano lagoon complex and Tano river. The expertise gained by the project benefited not only weed workers in Ghana but also those in neighbouring countries.
The water hyacinth mite Orthoglumna terebrantis, the bug Eccritotarsus catarienensis and the pathogen Cercospora piaropilrodmanii should be imported and released in addition to the already introduced weevils, N. bruchi and N. eichhorniae and moth S. albiguttalis. Once available and if necessary, the moth Acigona infusella could also be introduced. The pathogen lesions found on water hyacinth in the Tano lagoon complex, thought to be either Acremonium or Cercospora species, should be properly identified and possibly incorporated in the biological control programme.
If the bioagent populations build up to 4 weevils per hyacinth plant, and additional new host-specific water hyacinth agents are introduced within the next three to four years, water hyacinth should be under control in Ghana.
The project should play an active part in the control of water hyacinth proliferation in Burkina Faso. The Government should put at the disposal of the Burkinabes the expertise gained from the project. It should also provide financial support and bioagents to assist in the fight against the Burkina Faso infestation. The integration of water bodies between Ghana and its neighbouring countries calls for regional collaboration in the search for lasting solutions to the control of aquatic weeds in the sub-region.
It is recommended that local communities be involved in reporting aquatic weeds in an ongoing survey and awareness campaign.
It is recommended that donor assistance be sought to extend the project for at least another three years in order to consolidate the achievements of the first phase of the project.
PROJECT STAFF
Name Function
Kweku Amoako Atta deGraft-Johnson National Project Coordinator
Millicent A. Atchurey Secretary
Kwame Apenteng Driver
Nana Abeka Essien Technical Assistant
Roland Kofi Anim Technical Assistant
Isaac Morrison Coxswain/Boatman
David D. Wilson Entomologist/Collaborator
Simon Mensah Technician/Collaborator
STUDY TOURS
Participants Study Place Date
K. deGraft-Johnson Water hyacinth Fort Lauderdale, 11-14 Sept. 1995
control strategies Florida, USA
K. deGraft-Johnson, Education Northern, upper 30 Aug.-
W. Nyarko, campaigning east, upper west 6 Sept. 1995
M. Atchurey regions of Ghana
K. deGraft-Johnson Water hyacinth Black, White, Red 13-20 April 1996
investigation sites Voltas, Burkina Faso
MAJOR ITEMS OF EQUIPMENT PROVIDED
Quantity Item
1 Computer 486DX2/66
1 Computer 486DX/33
2 UPS 600 VA
Software: MS Office,
Word Perfect 6.0b for DOS, DBase
Version 2, Atlas GIS for Windows,
4 Atlas GIS training kit, etc.
1 Printer, Canon Laserjet
1 Photocopier, Canon
1 Automatic stabilizer, 3 000 Watts
2 Computer work station
1 Filing cabinet, 4-drawer
1 Boat, wooden
1 Vehicle, Land Rover Defender LHD 110 TDI
1 Vehicle, Station Wagon
1 Tow bar (on Land Rover)
1 Roof rack
1 Work boat with trailer, Yamaha
1 Colour television, Panasonic
1 Video camera, Panasonic
1 Video deck, Panasonic
5 Knapsack sprayers
20 Life jackets
1 GPS Trimble Ensign
1 Air conditioner, White-Westinghouse
15 Outboard motors with propeller guards, Johnson 25-HP
50 Plastic basins for rearing bioagents
DOCUMENTS PREPARED DURING THE PROJECT
Progress Report, September to December 1994.
Progress Report, January to December 1995.
Progress Report, January to December 1996.
K.A.A. deGraft-Johnson. Report on the International Expert Consultation on Strategy for Water Hyacinth Control, Fort Lauderdale, USA. 11-14 September, 1995.
J. Holcik. Restoration and protection of fish stocks in water bodies affected by aquatic weed infestations, 1st and 2nd Mission Reports. 1995.
J. Holcik. Restoration and protection of fish stocks in water bodies affected by aquatic weed infestations, 3rd Mission Report. 1995.
J. Holcik. Restoration and protection of fish stocks in water bodies affected by aquatic weed infestations. Project findings and recommendations. Technical Report.
Institute of Aquatic Biology. Assessment of fish stocks in the Abbey/Tano/Ehy lagoon complex. 1st Interim Report, September 1996.
Institute of Aquatic Biology. Assessment of fish stocks in the Abbey/Tano/Ehy lagoon complex. 1st Report, November 1996.
M.H. Julien. Integrated Control of Aquatic Weeds in Ghana. FAO Consultancy Report of 1st Mission.
M.H. Julien. Integrated Control of Aquatic Weeds in Ghana. FAO Consultancy Report of 2nd Mission.
K.A.A. deGraft-Johnson. Integrated Control of Aquatic Weeds in Ghana in "Strategies for Water Hyacinth Control". R. Charudattan, Ricardo Labrada, Ted C.Center, Christine Kelly-Begazo, eds. FAO, Rome 1996.
