||The purple sea urchin, Strongylocentrotus purpuratus , has a wide geographic distribution along the west coast of North America, and experiences a range of hydrodynamic forces. Understanding how this species responds to these forces will lend insight into life history studies. I conducted a field study on sea urchins collected from tide pools to determine if spine regeneration cycles correlate with relative wave exposure. I also conducted a laboratory experiment to determine if spine regeneration or microhabitat type alters resource allocation. Results indicate that spine repair is independent of somatic growth, and generally independent of reproductive growth. Microhabitat, however, affects sea urchin feeding, and therefore somatic and reproductive growth. These results suggest life history studies should consider sea urchin attachment strength and microhabitat more closely.