“Urchin prisons” is what Clint (my dive buddy) calls them.
Below are pictures from our in situ (in the field) grazing assays exploring the rates and preferences of herbivorous sea urchins in Hawaii. Why do this? Urchins are important consumers of algae on tropical coral reefs. Without urchins, algae may grow unchecked and smother the corals that build reef environments; and that’d be bad.
We know uchins are important in general, but there are 6 common species of herbivorous urchins in Maui’s reefs and we’re trying to figure out whether they all serve the same functions or perform complementary functions in reef systems. So, we collect them, provide a smorgasbord of algae, and observe what and how fast they eat. Pretty simple concept, but not so easy to to execute. Assays are currently underway: