The site

Geographical location

Malawi is a landlocked country in southeastern Africa, bordered by Zambia to the northwest, Tanzania to the northeast and Mozambique to the south, southwest and southeast. It lies between latitudes 9° and 18°S, and longitudes 32° and 36°E.

The Great Rift Valley runs through the country from north to south, and to the east of the valley lies Lake Malawi (also called Lake Nyasa), making up over three-quarters of Malawi's eastern boundary. Lake Malawi is sometimes called the Calendar Lake as it is about 587 km long and 84 km wide. The Shire River flows from the south end of the lake and joins the Zambezi River 400 kilometers farther south in Mozambique. The surface of Lake Malawi is located at 457 m above sea level, with a maximum depth of 701 metres (2,300 ft), which means the lake bottom is over 213 m below sea level at some points.

Lake Malawi has for millennia provided a major food source to the residents of its shores since its waters are rich in fish. Among the most popular are the four species of chambo, consisting of any one of four species in the subgenus Nyasalapia (Oreochromis karongae, O. lidole, O. saka and O. squamipinnis), as well as the closely related O. shiranus.

Other species that support important fisheries include the Lake Malawi sardine (Engraulicypris sardella) and the large kampango catfish (Bagrus meridionalis). Most fishing provides food for the increasing human population near the lake, but some are exported from Malawi. The wild population of fish is increasingly threatened by overfishing and water pollution. A drop in the lake's water level represents another threat, and is believed to be driven by water extraction by the increasing human population, climate change and deforestation.

The chambo and kampango have been particularly overfished (the kampango declined by about 90% from 2006 to 2016, O. karongae and O. squamipinnis by about 94%, and O. lidole might already be extinct and they are now seriously threatened. The IUCN recognizes 117 species of Malawi cichlids as threatened; some of these have tiny ranges and may be restricted to rocky coastlines only a few hundred meters long.

The University of Lilongwe (LUANAR) with the department of fisheries and aquaculture is running a farm which which was previously a financial drain on the College and thus Bunda Farm was commercialised in May 2005 and is now formally a limited liability company. The Bunda Campus farm site is located close to the Bunda Campus, (Google plus code: RQCH+58 Mwenda).  The solar powered hatchery was established at the Bund Campus farm in order to provide a template and a node for training for Malawian farmers.

Water source

The Bunda farm is located at a lake which ensures good quality water around the year to feed properly all the ponds at the site. The Bunda fish hatchery uses two sources of water; groundwater extracted from the ground using a pump, and Bunda water reservoir. The water from the reservoir passes through the bio filters as it is suspected not to be free from pathogens and some toxic pollutants. The groundwater does not pass through the bio filters basing on the fact that it is normally free from pathogens and also other pollutants. Water supply for the hatchery can be drawn from a deep and a shallow well. 

Water temperature and quality

The well water comes up with a temperature of about 18C°. The groundwater has a very good quality, although one point of concern was somewhat high levels of calcium carbonate concentration in the water from the deep well which can cause some problems with technical equipment's such as pumps. Preferably water from the shallow well is being used for the hatchery operation. Analyses of the well water showed that pH ranged from 7.8 in the pumping point to 8.0 in the hatchery. Whilst alkalinity ranged from 96.33mg/L to 96.39 mg/L. Furthermore, the readings for ammonia ranged 0.013 mg/L to 0.014 mg/L.    

Effluent water

A tilapia hatchery like those at the Bunda campus farm has naturally a very small amount of discharge water. The discharge water which becomes available when e.g. the water is changed in the larval tanks is being used to irrigate plant crops at the farm. Thus, the ammonium excreted from the fish is being used as a fertilizer. 

Weather and climate

Malawi has a sub-tropical climate, which is relatively dry and strongly seasonal. The warm-wet season stretches from November to April, during which 95% of the annual precipitation takes place. Annual average rainfall varies from 725mm to 2,500mm with Lilongwe having an average of 900mm, Blantyre 1,127mm, Mzuzu 1,289mm and Zomba 1,433mm. Extreme conditions include the drought that occurred in 1991/92 season and floods of 1988/89 season. The low-lying areas such as Lower Shire Valley and some localities in Salima and Karonga are more vulnerable to floods than higher grounds. A cool, dry winter season is evident from May to August with mean temperatures varying between 17 and 27 degrees Celsius, with temperatures falling between 4 and 10 degrees Celsius. In addition, frost may occur in isolated areas in June and July. A hot, dry season lasts from September to October with average temperatures varying between 25 and 37 degrees Celsius. Humidity ranges from 50% to 87% for the drier months of September/October and wetter months of January/February respectively. The map depicts average monthly temperatures and weather, sunny and cloudy days and the annual rainfall in Malawi as mean values from 2015 - 2019.

Infrastructure

The facility has good access to local infrastructure, and is accessible by car in about 15 min from the Bunda Campus. Electrical power is provided through the public grid, which, however frequently fails to provide electricity. This is the reason, why the tilapia hatchery was equipped with a solar power facility (see for details the chapter facility and equipment). The picture shows an aerial view from the farm area (taken with a drone), with the lake which provides the water for the ponds on the left side, even in the dry season.