Drought Research Paper

Introduction

This paper describes the potential effects of drought and the responses of the aquatic biota to the drought situations. The focus of the paper will be principally on the response of the invertebrates and fishes to seasonal and supra-seasonal droughts. As said by Bradshaw & Holzapfel (1988), Corti, Kohler & Sparks (1988), and Webster et al. (1996) the situation remains the same for stagnant waters, floodplain ponds, and lakes respectively. The drought have impact on both human and also on the aquatic ecosystems. To highlight the importance of the consideration of the impact of drought, it is important to have knowledge of how humans and aquatic biota respond to the drought. The goal of this paper is to summarise the major impacts

Drought is a climatic phenomenon which varies with locality and time at any location. As mention by Wilhite (2000) and Wilhite et al. (2007), drought is a very complex phenomenon and it remains a poorly understood climatic hazard. The drought can be classified into five forms, namely meteorological, hydrological, agricultural, ecological, and socioeconomic drought. The major focus is on those droughts that occur across seasons and are called ‘supra-seasonal droughts’. Even in areas with normal dry seasons or ‘summer droughts’, supra-seasonal droughts can occur due to the failure of normally expected wet seasons (Power et al., 2008). In some cases, a particular severe seasonal drought may lead to a supra-seasonal

The aquatic biota are algae, macroinvertebrates and fish. The importance of aquatic biota is its role as indicator organisms and also to detect contaminations analyses in fish. Some functions of macroinvertebrates in aquatic ecosystems is assessments of the health of aquatic community as these are easily collected and identified, also they are sensitive to changes in water. Further, they work particularly as recyclers of organic matter (Merritt and others, 1984) and this makes it secondary consumer in food chain. The macroinvertebrate include some insects, flatworms, mollusks and crustaceans. Also as the fish species are easy to collect and identify, it is advantageous in getting an idea of the health of aquatic community by analysing, which also gives an idea of the water quality. To generalise the impacts of drought on the aquatic biota, it is considered that the aquatic biota faces an increasing stress leading to loss of aquatic habitat, water quality decreases, and food resources reduction. Correspondingly, the biota may respond differently to the altered water quality which is due to the drought, equally important the physical habitat may become lethal for the biota, this might cause effects on behaviour, physiology and physically. The impact varies from place to place and varies to types of biota as well. Thus, cumulative of all the effect, some species survive