Previous research on fish-kelp relationships has found that
recruitment and the abundance of fishes is often positively related to the
abundance of kelp. Manipulations of kelp abundance, however, have
explored the distribution and abundance of fishes in the presence and absence
of kelp, but not variation in the density of kelp as a proxy for a gradient in
disturbance. Kevin conducted research at the Wrigley
Institute for Environmental Studies on Santa Catalina Island, off Los Angeles, California. The
objective of Kevin's study was to determine the effects of disturbance and the recovery
of giant kelp (Macrocystis pyrifera) on the recruitment and abundance
of fishes. He also monitored the recovery of kelp to address at what
point recovery from treatments of disturbance
was equivalent to undisturbed
kelp in terms of fish abundance. In addition, Kevin conducted experiments to determine whether
the distribution and morphology of fronds that represent mature vs. recovering kelp forests
influenced recruitment of fishes.
Although there were differences among
treatments for both recruits and older life stages of fishes, recovery of kelp
occurred within a 1-yr period, with no detectable differences in recruitment
or the abundance of older fishes among treatments thereafter. In his small-scale
experiment to determine whether there were differences between the
distribution and morphology of giant kelp that represent mature vs. recovering
kelp forests, the distribution of fronds was most important in recruitments
success of kelp bass (Paralabrax clathratus) and senorita (Oxyjulis
californica). These results demonstrate that a gradient of disturbance can
produce differences in recruitment and the abundance of older life stages that
would not be detected with the mere presence and absence of giant kelp.