1. Quite a few of my cousins have news on what eats urchins. Not all of their reports relate to Port Phillip Bay, but they give good clues to urchin life.

    All those spines. What’s the point? A sea urchin’s spiky outer shell would put a lot of potential predators off, but apparently some can handle the challenge. But first of all, you have to know where to look. Urchins mostly eat plant material, so a predator searchin’ for an urchin will head for the nearest seagrass bed or kelp forest. Predators include: people, cuttlefish, octopus and squid, fish (e.g. large trigger fish and wrasses), rakali, rock lobsters (Jasus edwardsii), and possibly 11 arm seastars.

    Tasmanian studies of caged sea urchins found that juveniles were more likely to be consumed by rock lobsters, but only large lobsters could take large urchins. On the other hand, studies of free roaming urchins found larger urchins were more likely to be taken by predators, probably because the younger/smaller urchins have more places to hide.