Current Research and Research Interests

M.S. Thesis:

Life history and ecology of a temperate, marine, herbivorous fish Girella nigricans

Herbivorous fishes are an important component of the marine environment because they have the ability to alter the composition of the community and convert primary production into fish tissue.  Grazing of algae by herbivores can alter marine communities by impacting the growth, recruitment, and mortality of algae.  By grazing algae, herbivorous fishes serve as a link between primary producers and secondary consumers.  Girella nigricans (opaleye)is one of the few herbivorous fishes in the temperate waters of Southern California.  The purpose of my study is to estimate productivity of opaleye off of Santa Catalina Island and to document the life history and ecology of these fish.  I am estimating productivity of opaleye by measuring the density of various size classes along underwater transects and combining these data with information on growth rates.  I am also determining the size and age at which the ontogenetic shift from carnivory to herbivory occurs by examining relative gut length and gut contents. Preliminary data indicate that opaleye do not become fully herbivorous until about 50mm standard length and that growth is exponential up to this length, at which point it slows.