INTRODUCTION OF SPECIES IN AQUATIC ECOSYSTEMS: CAUSES, PREVENTION AND CONTROL

Abstract

Non-native species may cause great damage to ecosystems. IUCN considers them as the second major cause worldwide for the loss of biodiversity. Water ecosystems are highly vulnerable to the impact and several research works have demonstrated that non-native species may alter the composition of native communities. Current paper provides the main causes for the introduction of species in water ecosystems and possible prevention and control measures against invading species. The main causes of their introduction in water environments are the destruction of geographic barriers, such as the construction of reservoirs and transposition canals in rivers; the establishment and improvement of natural stocks due to lack of planning and maintenance of breeding sites; aquarium and ornamentation of landscape. Tourism represented by sport fishing, biological control to exterminate the previous introduced species, associated fauna transported together with the water, substrates or hosts and waste water from the merchant navy also contribute for the introduction of species. The control of non-naïve species is rare and the identification of vectors, monitoring, public policies and studies are strategies that may decrease the environmental impacts caused by non-native species in aquatic ecosystems. Orientation and instructions on the environmental impact by non-native species should be provided for the population. The Internet may be an important tool against non-native species.