Northland Regional Council (NRC) monitors water quality at popular coastal bathing sites in Northland through the Recreational Bathing Water Quality Programme. During 2007-08, a total of 628 samples were collected from 44 sites. These samples were analysed for levels of illness causing bacteria. 94% of samples collected complied with the Ministry for the Environment (MfE) Microbiological Water Quality Guidelines. In addition, water at 15 sites was assessed for its suitability for recreational shellfish gathering. Using the MfE guidelines, only one site, Tinopai, had water quality that complied with the guidelines.

In 2007-08, there were a total of 133 marine farm consents in Northland. These marine farms are monitored on a biannual basis by NRC. During the 2007-08 monitoring year, 25 abatement notices were issued to marine farms that did not comply with the terms of their resource consent. Northland's six marinas are also monitored annually for compliance. In 2007-08, all six complied with the relevant limits for levels of bacteria and only one, Tutukaka, exceeded the limit for heavy metals.

The Estuarine Monitoring Programme (EMP) continued in 2007-08. Ecological assessments were made of the Whangarei harbour, Ruakaka estuary and Kerikeri inlet. Results to date suggest that human activity has adversely affected biological communities in these areas. More estuaries will be added to the programme in 2008-09. Water quality and sediment surveys were also undertaken during 2007-08 in the Bay of Islands and Whangarei Harbour. Results for 32 sites indicated low levels of bacteria and contaminants in the water, except after heavy rainfall when levels of contaminants became elevated above guideline values.