International Journal of Fisheries and Aquatic Sciences 1(2): 118-128, 2012 ISSN: 2049-8411 E-ISSN: 2049-842X © Maxwell Scientific Organization, 2012 Submitted: May 15, 2012 Accepted: June 23, 2012 Published: October 20, 2012 Corresponding Author: A.A. Oyedeji, Department of Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Nigeria 118 The Classification, Distribution, Control and Economic Importance of Aquatic Plants A.A. Oyedeji and J.F.N. Abowei Department of Biological Sciences, Faculty of Science, Niger Delta University, Wilberforce Island, Nigeria Abstract: The study reviews the classification, distribution, control and economic importance of aquatic plants to provide fish culturist information on some future challenges in culture fisheries management and practices. Aquatic plants have adapted to living in or on aquatic environments and constitute a problem in culture fisheries. They block navigational channels on the waterways and easily choke the propellers of boats. Many fish keepers keep aquatic plants in their tanks to control phytoplankton and moss by removing metabolites. Many species of aquatic plant are invasive species. However, some aquatic constitute the primary producers of aquatic ecosystems. They convert incident radiant energy of the sun to chemical energy in the presence of nutrients like phosphorous, nitrogen, iron, manganese, molybdenum and zinc. They are the foundation of the food web, in providing a nutritional base for zooplankton and subsequently to other invertebrates, shell fish and finfish. The productivity of any water body is determined by the amount of aquatic plants it contains as they are the major primary and secondary producers; hence, can be use as bio indicators. The study provides information on the meaning of aquatic plants, types of aquatic plants, characteristics of hydrophytes, adaptations, zonation, classification and control of aquatic weeds to provide the required information for fish culturists. Keywords: Aquatic plants, classification, control and economic importance, distribution INTRODUCTION Aquatic plants are hydrophytes and occupy different ecological niche in the aquatic environment. Aquatic vascular plants can be ferns or angiosperms from a variety of families, including the monocots and dicots, single-celled phytoplankton, periphyton and multicellular macrophytes. These plants have adapted to living in or on aquatic environments and constitute a problem in culture fisheries. In the high inter tidal zone, grasses and ferns are prevalent in ponds. The high density of water makes aquatic organisms more buoyant, so aquatic plants invest less resources in support tissues than terrestrial plants. Because aquatic plants are surrounded by water, water loss is not a problem. Thus, submerged plants lack the structural and protective structures produced by terrestrial plants. The water hyacinth has become a pest in many areas in the Niger Delta. It blocks navigational channels on the waterways and easily chokes the propellers of boats. In the high inter tidal zone, grasses and ferns are prevalent in ponds. They are not restricted to one particular zone. Regular cutting or removal of these plants from the pond is important. Aquatic plants can be classified according to their various zones, habitats or taxonomic groups. Many fish keepers keep aquatic plants in their tanks to control phytoplankton and moss by removing metabolites. Many species of aquatic plant are invasive species. Aquatic plants make particularly good weeds because they reproduce vegetatively from fragments. They constitute the primary producers of aquatic ecosystems. They convert incident radiant energy of the sun to chemical energy in the presence of nutrients like phosphorous, nitrogen, iron, manganese, molybdenum and zinc. In the aquatic ecosystem, the phytoplankton are the foundation of the food web, in providing a nutritional base for zooplankton and subsequently to other invertebrates, shell fish and finfish (Emmanuel and Onyema, 2007). The productivity of any water body is determined by the amount of plankton it contains as they are the major primary and secondary producers (Davies et al., 2009). Townsend et al. (2000) and Conde et al. (2007) reported that plankton communities serve as bases for food chain that supports the commercial fisheries. Davies et al. (2009) have also reported that phytoplankton communities are major producers of organic carbon in large rivers, a food source for planktonic consumers and may represent the primary oxygen source in low-gradient Rivers. Phytoplanktons are of great importance in bio- monitoring of pollution (Davies et al., 2009). The distributions, abundance, species diversity, species