In between, plant and animal communities hover in their pre-
ferred ranges in overlapping steps, slowly shifting in the same way
habitats shift as you climb a mountain, or as you look higher along a
tidal edge. Because of this broad spectrum of varied ecological zones,
California boasts some of the greatest diversity of all the fifty United
States. Its sheer length also makes it a perfect place to patiently, slowly,
and meticulously observe the way nature responds to a warming world.
An hour past dawn, the central California sun burns through the
morning haze. The waters of Monterey Bay are rising after a 6:21 a.m.
low tide. Rafe Sagarin, curly hair tousled by the unruly wind, gingerly
crosses the exposed granite tidepools like a teenager negotiating a clut-
tered bedroom floor. This intertidal tangle is a library to Sagarin, who
knows precisely where reefs of tube snails set their mucous nets,
striped sunburst anemones open their tentacles to the tides, and bar-
naclelike limpets farm algae for their supper.
Sagarin can also tell you that this tidal community is not what you
would have seen in the 1930s. In fact, it looks a lot more like southern
California. Sagarin knows because he has counted every critter along a
line between two brass bolts in the rocks, and compared them to a sim-
ilar count done 60 years earlier. That change is so big, so obvious, and
so important that an article he and colleague Sarah Gilman wrote about
it was published in the prestigious scientific journal Science while they
were still undergraduates. That research, which used their counts com-
bined with temperature and other measurements going back three-
quarters of a century, found that the most likely cause for the massive
changes in the kinds of species there was warming temperature. It is
exactly what one would expect to happen as the world’s climate
changes.
In 1993, Sagarin and Gilman were juniors at Stanford University,
among two-dozen students who took a term away from the main cam-
pus to study marine biology at the university’s Hopkins Marine Station
on the Monterey Peninsula. Upon arrival, the undergraduates were
treated to presentations about areas of research at the station, and proj-
ects they would have the opportunity to participate in.
It was not what Sagarin expected.
112 Orna Izakson