Obulala na Amani


Lake otter likely to boost western circuit tourism

By Cosmas Butunyi, Kisumu, 14 July 2007
Kenya’s western tourism circuit is set for a major boost with the regular sighting in Lake Victoria of the otter, a carnivorous, aquatic mammal mostly associated with the South American and Asian sea waters.

otter
Part of the Winam Gulf of Lake Victoria in Kisumu
The animal, the size of a domestic cat, has a thick, cylindrical, elongated body set on short, stocky legs, and is an agile swimmer whose adaptations include five-toe, webbed paws, the fore ones of which are shorter.  Unlike other aquatic mammals such as the seal, the otter lacks an insulating layer of body fat, but its active lifestyle which requires a lot of energy from food, generates enough heat to keep it warm. It catches its prey with its short, broad, rounded muzzle, and rather than draw its catch onto land, it often eats it in water. 

Dr Mordecai Ogada, a National Museums of Kenya researcher who has conducted numerous studies on the mammal, says the discovery of the rare fish-eating mammal could be a boon to eco-tourism, especially in the western circuit. “The otter is likely to be a major attraction for tourists, and this will help to mitigate its negative impact on fishing activities,” he says.

But to the Lake Victoria fishermen, the otter, known among the local communities as nduklu, is not a new phenomenon. It often raids their nets and causes fish losses. No cases have, however, been reported of the animal being killed by fishermen despite its destructive nature.  Another NMK research scientist, Ms Dorothy Nyingi, is full of praise for the fishermen’s tolerance of other resource users such as the otter, which is classified as vulnerable by the IUCN, the world conservation body, due to a decline in its distributional range. Thus, there is need to conserve the otter family in the lake, she adds.

Although the otter, like other vulnerable species, has legal protection by world conventions, these laws lack an enforcement framework. “Their conservation depends on the goodwill of fishermen and other people using the lake,” explains Ms Nyingi who has been involved in studies in the lake. The discovery of the otter, she says, will help to reduce pressure on fishing. “The fishermen can now use their boats to ferry tourists into the lake to spot the otter and make money instead of concentrating on fishing, which they are not making enough money out of anyway,” she argues.

There are two otter species in Kenya, Dr Ogada says. The lake basin is home to the spot-necked one, which is relatively small, with an average weight of 7kg. It is from dark brown to reddish brown and is distinguished by distinct markings of brown and white on the throat and the underside. The other — the African clawless otter — is larger and weighs up to 18kg. It inhabits highland streams and rivers and feeds on crabs and crayfish since it has no claws and cannot easily catch fish.

“The otter is very territorial, forming close-knit family groups of two parents and two or three kittens,” explains Dr Ogada. “Lake Victoria is home to one of about five otter families.” The mammal, he adds, has a large home range and marks boundaries with its faeces.

Dr Ogada is also involved in research to evaluate the otter’s faeces, especially its size and species composition in the lake. “The otter eats a lot all the time and it is not species-selective. Its diet is an accurate indication of the fish that are available to fishermen in the inshore habitats.” The otter primarily feeds on fish but also eats crabs, frogs and insect larvae, depending on food availability. Dr Ogada and his team collect the faeces and retrieves bones and scales from it. These are analysed in the laboratory to deduce the size and species of fish the otter eats.

They also analyse for comparison the stomach contents of the Nile perch, a voracious predatory fish species. “When the remains of crabs are present in an otter’s faeces, it means there are no fish available to the otter and this is a cause for alarm,” he says. “Crabs are the otter’s last choice of meal.”

Ms Nyingi says the Lake Victoria fisheries managers could adopt this method for monitoring the variation in composition of a fishery in terms of species and sizes. “What the otter catches and feeds on is what could be in the fisherman’s net, which makes the method of the otter feaces analysis reliable,” she explains. Preliminary results of the ongoing investigation reveal a significant overlap between the otter’s diet and that of the perch due to competition for food. “This suggests a threat on the otter population due to the tightening interface between the fishermen and the Nile perch, as are various inshore fish species,” she points out.  Areas of thick vegetation along the water edges are the otter’s primary habitat as they provide a hiding place. 

Its regular sighting in the lake has increased as a result of shoreline conservation efforts by the lobby, Hippo Focus Group. “We planted trees and papyrus reeds on the shore about a year ago, and since then we’ve been spotting the otter more often,” says the group chairman, Mr Titus Mulwa. When the fishermen conceived the lakeshore conservation idea, it was sandy, but now it teems with luxuriant vegetation. The trees and the papyrus planted along the shore, besides providing a haven for the otter, are also home to numerous birds.

The otter lives in a den, with one of the entrances usually underwater leading to another opening in the vegetation. It joins birds as an attraction of tourists visiting the Hippo Point, on the southwestern outskirts of Kisumu town. Members of the Hippo Focus Group act as tour guides along the beach, so named because it teems with the huge herbivore.  The group intends to develop eco-tourism at Hippo Point which, Mr Mulwa says, is a more sustainable activity. It intends to extend its activities to the lake’s other beaches. The otter has diverse importance. Besides being hunted for food and skin, the skin and claws, according to the fishermen, are also used in the preparation of love potion.

Crocodiles and pythons predate on the otter, whose survival is also affected by the factors affecting their environment. The water hyacinth is a major problem in the lake as, besides hindering the otter’s movement in water, it impairs its vision, which it depends on for capturing prey. The otter’s survival is affected also by pollution and siltation. The dwindling stocks due to over-fishing also has a negative impact on the little animal, as it means a food shortage. 

Ms Nyingi is fronting for aquaculture to reduce the pressure on the fish. Aquaculture involves rearing fish in ponds and tanks. “The culture of fish will provide an alternative source of fish for the fishermen and reduce pressure on the little that is left in the lake for use by otters,” she says. Dr Ogada and his team are looking at ways of encouraging fishermen to venture into fish keeping. They also intend to study the impact of the otter on aquaculture.

Aware that clearing vegetation around the lake may drive the otter away from the beach, Mr Mulwa and his group who are keen on maintaining it at the Hippo Point, are pursuing the conservation alternative.  The Kenya Tourism Board has been fronting for the opening up of the western circuit to tourists, and the resurgence of the rare mammal could be the beginning of the realisation of this dream.

source: NATION MEDIA