Freshwater Update 82, October 2019

NIWA’s recently commissioned autonomous hydroacoustic boat has been used to survey lakes for Auckland Council, including Lakes Rototoa and Tomarata. Hydroacoustic surveys provide detailed information about the underwater environment for lake management.

Contraptions that resemble upside-down kitchen sinks have been placed in the Waikawa River in Southland to attract a notoriously elusive native fish species.

Invasive pests are a concern to the New Zealand public and to those responsible for pest management. Pest aquatic plants pose a significant threat to the New Zealand environment and economy. NIWA is working to help protect our freshwater ecosystems from the effects of these plants.

Dynamic, processed-based integrated catchment models have the ability to simulate the changeable behaviour of complex processes in catchments. Since direct field measurements are rarely available at large-scales, these models help us to better understand hydrological and water quality processes.