What’s the world of the reef predators at Kingman like? What’s a place like where most of the fish biomass is at the top?
    In 2005 Ed DeMartini, Alan Friedlander, Stuart Sandin, and I conducted surveys of reef fishes at ten sites along the eastern and southern sides of Kingman. At each site we laid lines on the bottom and identified, counted, and visually estimated the size of all fishes within two meters (6.6 feet) on either side of the lines. We call these belt transects, of which a team of two conducted three per site. On each transect, two of us surveyed a surface of 200 square meters (2,153 square feet). We can later use the relationship between length and weight for every species and calculate the weight of reef fishes within a determined surface, or biomass. This is a standard method for estimating the abundance and biomass of reef fishes, and researchers in tropical and temperate seas use it frequently.
    Our 2005 study yielded a surprising result. Unlike most coral reefs that had been studied previously, top predators accounted for 85 percent of the total fish biomass on the fore reef of Kingman. To better grasp this biological implausibility, imagine the African plains with five pounds of lions per pound of wildebeest and zebra.
    The great abundance of predators has effects that propagate across the food chain, and we could witness some of these effects yesterday and today. In human-dominated reefs, where large predators have been fished out, the water column above the reef is filled with small fishes only a few inches in length, which eat some of the smallest inhabitants of the reef, the plankton. In Kingman, sharks and red snappers dominate the water column; the rest of the fishes keep a low profile. So low is their profile that they seldom venture a few inches above the bottom.
    Similar behavior has been observed at Yellowstone National Park after the reintroduction of wolves. Deer do not venture as much as before in the open meadows, and they spend more time watching for wolves. Their grazing impact on the forest is, therefore, greatly reduced. But we still do not know how the putative reduced activity of the smaller fishes affects the functioning of the Kingman reef ecosystem.
    When we were counting fishes yesterday before dusk, a dozen gray reef sharks came to inspect us and swam too close for our comfort. The landscape of fear also has an impact on us. In order to accomplish our scientific goals, we should ignore the sharks and focus. However, it is difficult to ignore such formidable animals while they swim effortlessly through the water. Whatever we do, we will also keep a low profile.

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