For example, sea urchins grazing on kelp stipes can destroy entire kelp forests that, when thriving, provide habitat for a variety of marine species.
Grazers also can inhibit recruitment, or settlement, of kelp by feeding on newly settled spore-producing plants (called sporophytes). Researchers have found that grazers measuring less than 1 inch in length, called mesograzers, may negatively impact the recruitment of kelp and other sessile, or attached, organisms.
Preliminary data collected from five sites in Kachemak Bay suggests that mesograzers such as chitons, limpets and gastropods are very abundant at those locations. Kelp forests are an important type of ecosystem in Kachemak Bay and an understanding of grazers' impacts on kelp would help researchers assess the year-to-year stability of local kelp beds.
In December 2004, I will begin field investigations in Kachemak Bay to determine 1) whether or not all grazers have a significant effect on the recruitment of sessile organisms; and 2) whether or not grazing by mesograzers in particular has a significant effect on the recruitment of sessile organisms.
These questions will be addressed by deploying and monitoring grazer exclusion cages and comparing their effect to non-caged areas at five sites in the bay for a period of 20 months.
During the study period, I will monitor how much of the caged and non-caged boulders are covered by sessile organisms. I'll also track grazer density and size, light levels, nutrient concentrations and relative current regimes at each location.
If you have questions about the Research Reserve, please visit www.kbayrr.org or call us at 235-4799.
Nick Harman is a graduate student at the University of Alaska Fairbanks School of Fisheries and Ocean Sciences.
We encourage you to add your comments. To prevent spam, comments with links are manually approved during the normal business day. Please be respectful of others with your comments, bear in mind anyone in the community may be reading your comments.
