What is Aquatic Animal

Humans made use of pesticides to kill pests infesting crops. This was done to increase agricultural yields and improve public health. Pesticides however turn out to be damaging for the environment, causing many harmful impacts. Certain pesticides after being applied to the environment show long-term residual effects while others show acute fatal effects particularly to aquatic life. For example, organochlorine pesticides are persistent in the environment; as a result of this, these pesticides find their way to contaminate ground water, surface water, food products, air, soil, and may also affect human beings through direct contact. Pesticide exposure to humans has been found to be an important cause of some diseases such as cancer, respiratory diseases, skin diseases, endocrine disruption, and reproduction disorders. It is this aspect of pesticides in the environment that has raised concern among environmental scientists to study their behavior in the environment and then come out with a sound alternative so as to rescue the human population from their adverse effects. Fifty years (half a century) after Rachel Carson's warning to the world about the devastating effect pesticides have on birds and beneficial insects, pesticides continue to be in use. Continued usage of pesticides can be described as a massive chemical assault on our environment which threatens the survival of many birds, fish, insects, and small aquatic organisms that form the basis of the food web. More generally, pesticides reduce species diversity in the animal kingdom and contribute to population decline in animals and plants by destroying habitats, reducing food supplies, and impairing reproduction. Organisms in ecosystems exist in complex interdependent associations such that losses of one keystone species as a result of pesticides (or other causes) can have far reaching and unpredictable effects. A keystone species is a species that is disproportionately connected to more species in the food-web. The many connections that a keystone species holds mean that it maintains the organization and structure of entire communities. The loss of a keystone species results in a range of dramatic effects that alters trophic structure, other food-web connections, and can cause the extinction of other species in the community. A pesticide may eliminate a species essential to the functioning of the entire community, or it may promote the dominance of undesired species or it may simply decrease the number and variety of species present in the community. This may disrupt the dynamics of the food webs in the community by breaking the existing dietary linkages between species.