Port Phillip Bay, in Melbourne, has been invaded by giant crabs.
Every year, hundreds upon hundreds of spider crabs flock to Melbourne’s cooler waters in order to shed their hard outer shells. Whilst their new shells are hardening, the crabs gather together, protecting themselves from predators who take advantage of their lack of shell. Some colonies stack themselves ten deep for extra protection. Once the crabs have left the bay, hundreds of thousands of empty crab shells will be left on the sea floor.
Australian aquatic scientist Stephanie Marris, captured the convergence of these spider crabs, and has published the documentary on Youtube.