Tidepool nutrient cycling manipulations

Summer number 1 of our collaborative research project with the Bracken and Martiny lab groups at UC Irvine is proceeding nicely. Our teams have been manipulating mobile grazers, such as limpets, littorine snails, chitons, and hermit crabs, in experimental tidepools in order to measure the growth responses of the photosynthetic algae in these pools (among many other variables we are measuring). Those algae need to take up nutrients from the tidepool water in order to grow, including nitrogen products, which the herbivore grazers just happen to be recycling through their urine as they eat other algae in the pools.

Censusing mobile herbivores in experimental tidepools at Corona Del Mar.

Very low tides often occur in the middle of the night during summer in southern California, so this often requires working long hours in the darkness, counting snails and measuring algae density. At least parking is easy to find at 11pm.

This work is part of a National Science Foundation sponsored project titled “Collaborative Research: Context-dependency of top-down vs. bottom-up effects of herbivores on marine primary producers” (NSF-OCE 1736891, NSF-OCE 1737065).