Investigations into the use of benthic foraminifera as indicators for water quality on the Great Barrier Reef (MTSRF Project 3.7.1)

Sediment samples for foraminiferan community analysis were collected from 20 reefs located between 13.5°S and 20.5°S within the Great Barrier Reef. Most of these reefs are inshore fringing reefs which can be grouped into three distinct geographical regions: eight reefs of the Whitsunday area (collected in August 2004), four reefs from Princess Charlotte Bay, and four from the Wet Tropic area (both collected in October 2004). Sediments were also collected from two midshelf reefs (Charity and Bait Reefs) in August 2004, and two outer shelf reefs (Hastings and Flynn Reefs) in January 2005.

On each reef one location of the sheltered back reef and one on the more exposed front reef was chosen. At each location, two samples of > 50 g sediment were carefully scraped from the top 0.5 - 1 cm at 7 to 9 m depth. Samples were fixed in 100% ethanol.

To determine sediment chemistry and granulometry parameters, additional sediment samples were collected at the same sites during collection of the foraminifera. In the Whitsunday area, additional sediment samples were collected in August 2005 and February 2006. The sediment samples were taken in triplicate from each location using mini-corers (cut-off 60 ml syringes); only the top 1 cm of sediment was used.

Surveys in the Whitsunday region of the GBR included a more detailed study of foraminifera along an inshore-offshore transect.