If you look closely, the shores of the slough are crawling! Look for crabs and snails living on the shoreline. Crabs are crustaceans, who have an outer exoskeleton that they shed as they grow bigger.  Snails are mollusks, but these snails don’t look like those in your garden. They have long, skinny spiral shells and can be found both on the shore and affixed to plant stems. And there’s more, the water of the slough contains a host of plankton-size and larger invertebrate animals swimming around.