Strange, leathery capsules sometimes wash up along Bayside's shoreline. Often mistaken for seaweed or seed pods, these objects are actually shark eggcases, also known as mermaid's purses.
Recording these finds is the focus of the Great Shark Eggcase Hunt, a global citizen science project helping researchers learn where egg‑laying sharks, skates and rays live and reproduce. Results from the 2025 hunt recorded thousands of eggcases worldwide, including many from Australian waters.
One species commonly found locally is the Port Jackson shark, which lays distinctive spiral‑shaped eggcases that are often wedged into rocky crevices. These sharks are known to inhabit Port Phillip Bay, including reef areas such as Ricketts Point Marine Sanctuary.
Even empty eggcases provide valuable data, helping scientists map breeding areas and better understand marine ecosystems.
Take part by keeping an eye out while walking along the beach or snorkelling. If you find an eggcase, take a photo and upload your sighting.
