Rock Pool Clearing on Granite Outcrops

In a recent trip to Perth, Australia, Steve and a colleague at Edith Cowan University (Dr. Clint McCullough) tested methodology to clear rock pools on granite outcrops in Western Australia. Below is the sequence of this process and outlines the modifications of this process to accommodate early failures. The bottom of the sequence shows the videos of the high-pressure washing process.

The initial portion of pool clearing is to scrape the soil from the bottom of the pool. Above are two pools in various stages of such sediment removal. We used brushes to scrape the soil into dust pans or trowels. The left-most photo shows Clint with a half-done pool and the middle photo is of a completed pool. The right photo is of the resulting sediment.

Our initial idea was to spray a bleach solution onto the remaining soil and then heat the rock with a blow torch to kill any residual eggs. The left photo shows Clint spraying down a pool with the bleach solution and the right shows the blow torch heating the rock bottom.

After we "cleared" the pools, we added water to refill the pools (left photo). We were not happy with the amount of soil that needed to be sterlized, which was obvious by the muddy quality of the water after the pool had been refilled (right photo). Thus, we decided another tactic was required.

A better strategy for pool clearing turned out to be using a high-pressure (3000 psi) power washer, as shown above (left photo). The washer was gas-driven and fit into the back of Clint's 4-wheel drive truck (a "ute"). The pressure washer cleared the pools in a matter of minutes, leaving a bare-rock pool (right photo)!

A video of Clint using the power-washer to clear a pool should start to the left. You need Quicktime to view the video and some patience (the file is quite large).

A second video (an .avi file) of the power-washer process, this time with Steve clearing a pool.

E-mail address : SCWeeks@uakron.edu.