Figure 9 - A tyre reef unit prior to submersion, showing the nylon straps and base. Photo courtesy of Eric Yau (See Appendix I).
Each tyre reef unit uses a significant number of tyres. The pilot projects have
already used 37,500 tyres to date. The artificial reefs are also periodically checked to
perform “quantitative underwater fish surveys”. The tyre units show significant
growth and stability, as can be seen in Figure 8.