Seascapes and foraging success: movement and resource discovery by a benthic marine herbivore

We examined the process of resource discovery in the context of a heterogeneous seascape using sea urchins and drift kelp in urchin barrens as a model system. Under field conditions, we manipulated both the presence of a highly valuable resource (drift kelp) and a barrier to movement (sandy substratum) to test the interacting influence of these two factors on the process of resource discovery in barren grounds by urchins. We removed all foraging urchins from replicate areas and monitored urchin recolonization and kelp consumption under the different treatments. We tested two hypotheses: 1) unstable substratum is a barrier to urchin movement and 2) the movement behaviour of sea urchins is modified by the presence of drift kelp.  

All data used for analysis and presentation of the results are included here (experimental clearing data, kelp consumption in experimental units, clod card dissolution during experimental manipulations, and size-frequency of urchin populations at study sites).