Lake sediment phosphorus release management—Decision support and risk assessment framework

The release of phosphorus (P) from the sediments of eutrophic lakes is often associated with the proliferation of nuisance algal blooms, especially cyanobacteria. The successful implementation of management actions aimed at reducing such algal blooms requires an integrated approach, including both external and internal nutrient loads. The internal load of P can be a significant source of P for primary production, with greatest inputs occurring when lakes stratify and the hypolimnetic waters become anoxic. We reviewed the nature and characteristics of New Zealand lakes in relation to factors which affect the application of technologies to manage internal P loads within individual lakes. New Zealand's windy maritime climate causes lakes to mix more deeply than lakes in continental areas, which are characterised by relatively hot, calm summers. We assessed a range of management options which may be used to control internal P loads, and considered these in a de cision‐support framework aimed at ident...