A marine biologist is comparing two different formulations of artificial reef substrates to see which is more effective at promoting coral larval settlement.

On Reef Block A, 40 settlement tiles are coated with a standard calcium carbonate mixture. On Reef Block B, 40 identical tiles are coated with a new bioactive organic polymer.

The results after three weeks are shown in Table 1 below.

Table 1: Number of tiles showing successful colonization of coral recruits

After counting the recruits, the researcher took high-resolution macro-photographs of each tile and wrote a detailed narrative log describing the physical distribution, color variations, and general health of the coral larvae on each surface.