Sediment

Mass deforestation in Picton Harbour (1920s). Courtesy of Picton Historical Society.

Erosion is depleting soil resources while increasing sediment loads and impacting downstream receiving environments.

Sediment is one of the main threats to New Zealand’s marine environment. Erosion of soil from land and its deposition in estuaries and the sea is largely a natural process, but the rate sediment is being deposited is higher now than before human activities disturbed the natural land cover.

Historical catchment deforestation, large-scale conversion to pastoral agriculture, land-use intensification and catchment disturbance have all contributed to increased erosion rates in Marlborough.