Nutrient data from rivers discharging into the Great Barrier Reef lagoon

Nutrient data was obtained from the lower reaches and estuaries of 23 rivers discharging into the Great Barrier Reef lagoon. Wet season time series were measured in five rivers (South Johnstone River, Tully River, Herbert River, Burdekin River and Fitzroy River). Seven rivers have catchments in the wet tropical region (Barron River, Mulgrave River, Russell River, North Johnstone River, South Johnstone River, Tully River and Murray River). The Normanby River and Herbert River have mixed wet/dry catchments. Two major dry catchment rivers, the Burdekin River and the Fitzroy River were sampled.Sporadic samples, usually from the estuary, were collected in the course of other projects. These include Jacky Jacky Creek, Escape River, Pascoe River, Claudie River, Lockhardt River, McIvor River, Daintree River, Ross River, Alligator Creek, Haughton River, Barratta Creek and Pioneer River.In most cases, near-surface water samples were collected from mid-channel, above the level of saltwater intrusion, using a clean plastic bucket or jar lowered by rope. Prior to December 1991, only single water samples were collected at any one time; thereafter, collection of duplicate water samples was progressively introduced into all sampling programs. Sampling was undertaken to:1. quantify terrestrial input fluxes of nutrient elements (N, P, Si) which influence plankton productivity, reef productivity and water quality in the central GBR region2. resolve regional, seasonal and event-associated exports of nutrients from north Queensland rivers with both wet and dry catchments3. resolve the dynamics of river nutrient fluxes during flood events, especially large events associated with cyclones and monsoonal rain depression4. collect data suitable for parameterizing numerical flow discharge models for major north Queensland river systems Sampling was conducted through cooperative arrangements between AIMS and other government agencies. These include the Great Barrier Reef Marine Park Authority (GBRMPA), Queensland Department of Primary Industries (QDPI), Bureau of Sugar Experiment Stations (BSES), Queensland Water Resources Commission (QWRC), Cairns City Council (CCC), CSIRO and Central Queensland University (CQU). A number of volunteers also contributed to the sampling effort.