As a sub-project of the now discontinued water quality component of the AIMS Long-term Monitoring Project, sediments were examined along cross-shelf transects commencing at the mouths of the Johnstone and Barron Rivers, which drain heavily cultivated areas. Results were compared with sediments from a transect commencing near the Pascoe River, which drains an uncultivated area of Cape York. Observations were made between November 1992 and April 1996. Sampling was conducted in alternate dry and wet seasons 1992-1993 but only in wet (summer) season 1994 and 1995. Inshore stations were located within 1 km of the shore and seaward stations approximately 20km offshore.Stations were located along and across the Great Barrier Reef shelf from 3 river mouths (Barron, Johnstone and Pascoe) out to individual reefs: Pascoe River mouth, off Portland Roads, Dolphin Reef, Bourke Reef; Barron River mouth, Port Douglas, Low Isles, Green Island, Thetford Reef, Fitzroy Island; Flying Fish Point (at the mouth of the North Johnstone River), Russell Heads, North Barnard Island, Flora Reef, Feather Reef, Ellison Reef.Nutrient flux samples were examined for dissolved inorganic nutrients (ammonium, nitrite, nitrate, phosphate) using standard automated techniques. Solid-phase nutrients were measured in bulk sediment samples for total organic carbon, total carbon, total nitrogen and total phosphorus. Total carbonate was estimated by the difference between total carbon and total organic carbon concentrations multiplied by 8.33.
This research was undertaken to determine the extent of temporal and spatial variability of nutrient regeneration rates and nutrient concentrations in surface sediments of the far northern GBR shelf by:1. assess the role of river run-off in delivering nutrient and sediment loads in the GBR by monitoring changes in the quantities of nutrients (and related variables) in the interstitial porewaters and bulk sediments.2. measure the rates of nutrient flux across the sediment-water interface in order to determine the flux nutrients between the sediments and the overlying water column.
Parameters measured: Carbon/Nitrogen Total Bulk Sediment, Particulate Organic Carbon (POC), Sedimentary Organic Carbon, Total Dissolved Carbon, Dissolved Inorganic Nitrogen, Total Dissolved Nitrogen, Total Dissolved Phosphorus, Salinity.The water quality component of the AIMS Long-term Monitoring Project has a separate metadata record.
