Reef Watch uses a number of different reef survey techniques to gather information on the reefs health. Each method has a different focus so that overall they are able to obtain a real comprehensive image of what is going on.
The method employed in the monitoring program are easily mastered by non trained divers, yet are robust enough to be used by experts.
Fish Surveys
The Reef watch Fish survey method known as a 50m belt transect survey. Divers dive a straight line at a constant depth and record the fish ( name, numbers, male/female/juvenile) they observe in a 3m belt on either side of the transect line.
After this first pass, divers do a second return pass back along the transect line searching under the algae canopy and any ledges to record hidden or cryptic fish.
Note, fish surveys were also completed in shallow waters by snorkelers.
Benthic Quadrats
The reef Watch Quadrat Survey method uses a 1m square weighted rope to sample the benthic "bottom" environment.
This is the identification of benthic ( bottom dwelling) organisms.
Students are given waterproof charts on which they identify and record benthic Flora and Fauna, they record also approximate areas within the quadrant that these plants and animals occupy.
Line intercept Transect Surveys
Line intercept Transecting (LIT) is an excellent tool for looking at the structure of the macro algae community. This is the same technique used by the University of Adelaide to monitor reef health and provides Reef Watch scientists with high quality scientific data.
The LIT involves placing a weighted ruler over the reef community and recording writing down what is found directly below it. By repeating this a number of times it can be determined what types of organisms are found on the reef, the relative proportions of each, and also whether there are any identifiable patterns.
Divers use a simple codes system to help identify and record the flora and fauna found within the fields they are surveying. Code are based on obvious characteristics such bas colour and basic shape. (see sample sheets)
REPORTING RESULTS After a diver has completed a Reef Watch benthic survey dive on the reef the resultant forms are, either, sent by post to Reef Watch care of the Conservation Council of South Australia, or they are entered on-line via the Reef Watch home page.
The value to the community of programs like this cannot be underestimated. It enables the community to become involved in the process of monitoring an aspect of their environment, this support is essential for the long term care and welfare of such a wonderfully diverse reef system. The scientific data gathered will, over a period of time produce a sound knowledge base that will assist managers and policy designers to make educated and informed decisions. |
