Aquatic Plant Monitoring in the Broads

Abstract

The Broads is well known as the UK’s largest protected wetland. The Broads Authority, part of the family of National Parks, is the body with responsibility for overall delivery of biodiversity within this wetland area covering some 301 km². Part of this responsibility is to monitor, research and restore the broads, or shallow lakes, in accordance to European targets set under the Habitats and Water Framework Directives.

A history of monitoring and recording aquatic plants (macrophytes) in The Broads has resulted in well used long-term datasets. These data are proving vital to understanding of the functioning of the complex interconnected series of shallow lakes as well as determining the success of the many restoration projects.

Aquatic plants provide excellent information about the condition of waterbodies and coupled with water quality information lake restoration programmes can be initiated. Gaining the information about aquatic plants can be relatively straightforward with access to a boat and appropriate training in identification skills and safety. However careful consideration is required when selecting a survey method, particularly when setting up long-term surveys. A robust replicable methodology that allows comparison within or between sites that may have different plants biomass, species assemblage or access issues is essential.

Three methods of macrophyte monitoring are described; transect and point surveys from boats and point sampling by SCUBA diving. The development of hydroacoustic survey methodology is also briefly described along with examples of some of the data derived from the different methods and a comparison of these different methods used in The Broads.