Mana Pools

• Category: Inland Aquatic Biomes.
• Geographic Location: Africa.
• Summary: A floodplain along the middle Zambezi River hosts a network of permanent and seasonal pools that provide water to a remarkable concentration of wildlife through the dry season.

Mana Pools is a complex habitat network of lakes, wetlands, and woodlands located along the northern border of Zimbabwe on the south bank of the Zambezi River. Not far south of Victoria Falls, the course of the Zambezi has gradually drifted northward across the floodplain, carving out channels and pools that fill with water during the rainy season—and retain much of that water throughout the dry season, supporting perhaps the greatest variety of large mammal herds on the African continent. There is concern, however, that changes in the natural flood regime of the river since the construction of two dams has altered the character of the floodplain and will put undue stress on its native species.

Geography and Habitat Types

Mana Pools derives its name from the indigenous Shona word for “four,” referring to the four largest permanent pools created here by the meandering Zambezi. Many more seasonal pools and ponds dot the region, forming a complex network of watering holes flanked by woodlands. Three distinct habitats are found in the Mana Pools biome: jesse bush, mopane woodland, and the floodplain.

Jesse bush is a term encompassing a variety of shrubs, thorny bushes, and vines that grow so closely together that the bush is nearly impenetrable. A network of trails, created largely by elephants, rhinos, and buffaloes traveling between water holes create highways through the brush for smaller animals. The dense brush, in effect, creates a safe haven and refuge from the sun for many species.

Mopane trees (Colophospermummopane) grow in poor soils in hot, low-lying areas; they tend to dominate where the soil is heavily clay-based. The clay in the soil retains pools of water for animals to drink, and mopane leaves provide valuable protein during the dry season. Mopane wood is tough and termite-resistant, making it prized for construction and firewood among natives. Mopane woodland is usually open and easily walked because the soil generally does not support dense undergrowth, while tree canopies are high with scant understory, and sparse in distribution.

The sandier, alluvial soils of the floodplain contain tracts of winterthorn, also favored fodder for herbivores, and more diverse woodlands including baobab, wild fig, sausage tree, dense albeida trees, and Natal mahogany. This area used to flood regularly during heavy rains before the construction of the Kariba Dam upstream on the Zambezi. Many feared damming the river would deprive the soil of new alluvial deposits.

Wildlife

Rich and varied mammal populations concentrate on the floodplains during the dry season when water is scarce elsewhere and when winterthorn trees drop their protein-rich pods. The Mana Pools biome has Zimbabwe’s largest populations of hippopotamuses and Nile crocodiles. It also hosts huge herds of elephants, buffaloes, zebra, waterbuck, and several antelope species. Predators following the herds include lions, hyenas, leopards, and cheetahs.

Bird life is seasonally rich here, both in the bush and on the river. More than 450 species of birds have been recorded. Spinetail, bee-eater, flycatcher, swift, sandpiper, plover, and redshank are among the sand-bank nesters and migrant waders that flock to the pools each year. Raptors such as Pel’s fishing-owl (Scotopelia peli) and western banded snake-eagle (Circaetus cinerascens) use the tangled array of perches to good effect and spend time int he biome.

Effects of Human Activity

Since the construction of the Kariba Dam near Victoria Falls, and the Cabora Bassa Dam where the Lower Zambezi begins, the character of the floodplain has changed. The river is now regulated to the point that it rarely floods, and then only locally. Construction of the holding reservoirs Lake Kariba in 1959 and Lake Cabora Bassa in 1974 converted a once-fast-moving river into a sluggish body of water. This river is now unable to carry its silt load, depositing islands of sediment in the center of the riverbed which blocks the flow of the water and forces it to run faster on the edges, increasing erosion on the banks.

Mana Pools National Park, a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site since 1984, is located on the south bank of the Zambezi River, along the northern border of Zimbabwe. It is part of the Parks and Wildlife Estate that runs on both sides of the Middle and Lower Zambezi, from the Kariba Dam to the Mozambique border. There is no permanent human habitation in Mana Pools National Park. Strict regulation of visitor movements and vehicle traffic, combined with the remoteness of the site, has helped keep the park unspoiled. The presence of an array of tropical diseases, including sleeping sickness, malaria, and bilharzia, also discourages settlement.

In 1989, oil exploration within the preserve was proposed; many concerns were raised about impacts such as industrial littering, erosion, and improved access for poachers. Yet another dam was proposed for the Mapata Gorge, which would submerge much of the Middle Zambezi valley and halve the carrying capacity of the Mana Pools. Additional tourist facilities have also been suggested, which would overcrowd and strain the tourist resources currently in place. Environmental impact studies have shown that these and other development ideas would cause too much damage, and the ideas were abandoned. Currently, the greatest threat to the integrity of Mana Pools is the regulation of the flow of the Zambezi by the Kariba Dam.

In June 2010, Zimbabwe’s Middle Zambezi Valley was granted enhanced conservation status as a Biosphere Reserve by UNESCO. This reserve extends from Lake Kariba down the river almost to the border of Mozambique, and includes Mana Pools and the adjoining Sapi and Chewore safari areas. Strictly controlled recreational hunting is permitted in the safari areas in the environmental management plan. While local operators are trying to increase tourism in the region, several private and public campaigns are working to protect Mana Pools from increased human interface and keep this portion of Zimbabwe’s heritage intact for future generations to enjoy.

In May of 2023, Zimparks signed a memorandum of understanding with Peace-Parks Foundation that grants $23.4 million towards the conservancy and rehabilitation of the Mana Pools. The money provides a trust aimed at funding the development and protection of the area for next twenty years.

Climate change has already made its effects felt in the Zambezi River catchment area, as recent annual flows are down from persistent shortfall in annual precipitation. Scientists have predicted remorseless temperature increases for the region, which could act to impose drought by the action of increased evaporation. However, some areas are receiving more frequent storms to the point where the risk of flooding has become a constant. Heavy flooding in 2022 damaged infrastructure and bridges leading to Mana Pools National Park. Deforestation and even desertification have been discussed in some parts of the region that depends upon the Mana Pools. Each of the pressures will make survival harder for plant and animal species here, and taken together may threaten even the current, somewhat degraded status quo of water management on the Zambezi River.

Bibliography

Bone, Craig and Alistair Chambers. African Seasons: Wildlife at the Waterhole. London: Dragon’s World, 1992.

Chenje, Munyaradzi. State of the Environment 2000: Zambezi Basin, Vol 1. SADC, Environment and Land Management Sector, 2000.

Gwaze, Farai. “Zimparks, Peace Parks in Conservation Partnership.” The Zimbabwean, 30 Nov. 2023, www.thezimbabwean.co/2023/11/zimparks-peace-parks-in-conservation-partnership/. Accessed 4 Oct. 2024.

Henning, David. "Mana Pools National Park Nearing Full Accessibility after Reconstruction." Getaway, 22 Apr. 2022, www.getaway.co.za/travel-news/mana-pools-national-park-nearing-full-accessibility-after-reconstruction/. Accessed 4 Oct. 2024.

Pacey, Paddy. "Managing Mana Pools." Whole Earth, 12 Oct. 2020, wholeeartheducation.com/managing-mana-pools/. Accessed 4 Oct. 2024.

Swain, Ashok, et al. “Zambezi River Basin: A Risk Zone of Climate Change and Economic Vulnerability.” New Routes, vol. 17, no. 3, 2012.

Timberlake, Jonathan. Biodiversity of the Zambezi Basin Wetlands: Review and Preliminary Assessment of Available Information. International Union for the Conservation of Nature, 2000.