Studies on the Ecology and Control Oftypha Species in Hadejia-Nguru Wetlands, Nigeria

ABSTRACT

Aspects of ecology and managementofTypha species in Hadejia-Nguru wetland were studied for a period of twenty-four months between January 2010 to December 2011.

The aim was to identify the resident species of Typha, Physico-chemical parameters, soil and sediment associated with proliferationofTyphaspecies, profer Management solutions to the Hadejia-Nguru wetlands community.

The wetland has an area of about 58,100 hectares of which35,000 hectares were infested by Typha species.

Typha proliferation causes a number of ecological problems which include the transformation of aquatic environments into terrestrial ones, interference with various methods of catching fish, blockade of river channels, and impeding navigation.

Generallytheybecame a nuisance by affecting the social and well-being of the people who ultimately depend on the wetlands for their livelihoods.

It also alters the biodiversity of aquatic ecosystems as well as a reduction in light penetration within the aquatic system.

The study involved dividing the wetlands into three segments Upper, Middle, and Lower courses. Typha species, water, soil, and sediment samples, were collected in these segments, and the impact of Typha species on fish catch and distribution was evaluated by dividing each segment into two,

Typha un-infested an infested area. For the biological control; each segment was divided into four each containing 2000 species of Typha interplant with 50kg, 25kg, 10kg, and without Phragmites karka respectively.

INTRODUCTION

Background of Study

Mitsch and Gosselink (1986) defined wetlands as lands that are transiting between terrestrial and aquatic ecosystems where the water table is usually at or near the surface, or the land is covered by shallow water (Prasad et al., 2002).

The importance of wetlands is increasingly receiving attention as they contribute to a healthy environment in many ways. This comprises a vast complexity of direct and indirect uses (Acharya, 1998), which include:

(1) water retention during dry periods, thus keeping the water table high and relatively stable; (2) flood mitigation and (3) trapping of suspended solids and attached , thus, streams flowing into lakes by way of wetland areas will transport fewer suspended solids and nutrients to the lakes than if they flow directly into the lakes (Prasad et al., 2002).

Removal of such wetland systems because of urbanization or other factors typically affects wetland water quality (Barbier, 2002).

Additionally, wetlands are important areas for wildlife, because they provide resting and stop-over places, as well refuges for migrating and resident animals (Lameed, 2011).

As with any natural habitat, wetlands are important in supporting species diversity. Other values include the use of the wetlands for domestic and agro-industrial water supply (Ibrahim and  Chiroma,  1998), harvesting of bio-resources, such as fish and plants, and the function of wetlands in groundwater recharge and discharge (Yahaya et al., 2010).

The Hadejia-Nguru wetlands are on the list of Ramsar wetlands of international importance, meaning 58,100 ha in size, and are designated as Ramsar Site. The wetlands are important for waterbirds, both as breeding grounds and water for birds.