Shoalwater Islands

Shoalwater Islands Marine Park is a 6,824-hectare marine protected area in the Rockingham region, 40 km south of Perth, encompassing the waters surrounding Penguin Island, Seal Island, Bird Island, Buller Island, Carnac Island, and adjacent shallow marine habitats. The marine park protects one of the most biologically productive and accessible marine environments near a major Australian city, supporting little penguins, Australian sea lions, bottlenose dolphins, and diverse coastal marine communities. The park is managed by DBCA.

Shoalwater Islands Marine Park supports a remarkable concentration of marine wildlife. Australian sea lions (Neophoca cinerea) — a species endemic to Australia and classified as endangered — haul out on Seal Island and adjacent sandbars. Little penguins (Eudyptula minor) breed on Penguin Island. Indo-Pacific bottlenose dolphins (Tursiops aduncus) are year-round residents and are famous for their interactions with visitors. Humpback whales pass through during migration (September–November). Osprey nest on island trees. The seagrass meadows (Posidonia australis) support dugongs, cuttlefish, and juvenile fish. Weedy sea dragons are present in the kelp and seagrass communities.

Posidonia australis and P. sinuosa seagrass form extensive meadows on the shallow Rottnest Shelf, providing the primary food for dugongs and critical nursery habitat for fish. Kelp and fucoid algal communities develop on rocky reefs. Crustose coralline algae carpet reef surfaces. Island vegetation is low coastal scrub of saltbush and native grasses.

The Rottnest Shelf — Holocene and Pleistocene Tamala Limestone — creates the shallow reef and island systems of the marine park. The islands are remnant limestone platforms exposed as sea levels fell after the last interglacial. Sandy seabed in shallow water between islands supports seagrass. Beachrock (cemented beach sand) occurs on island beaches.

Warm Mediterranean climate. Water temperatures 17–24°C, influenced by the south-flowing Leeuwin Current. Summer Fremantle Doctor (afternoon sea breeze) creates choppy conditions offshore. Little penguin breeding occurs in winter-spring. Sea lion pups are born in January–March.

The Shoalwater Islands are within Bindjareb Noongar sea country. Noongar people harvested coastal marine resources from this area over thousands of years. Rockingham was an early European settlement site on the WA coast (1830s).

Shoalwater Islands Marine Park was established in 1990 to protect the exceptional marine wildlife and habitats of the Rockingham coast. Management has focused on regulating vessel traffic near sea lion and penguin colonies, controlling fishing in sensitive areas, and managing dolphin interaction programs.

Sea lion snorkelling tours at Seal Island — a world-class marine wildlife experience. Penguin Island tours (by ferry from Rockingham). Dolphin Swim Eco Tours with the resident bottlenose dolphin pod. Kayaking and snorkelling in the clear shallow waters. Whale watching in spring. Scenic boat tours.

Departures from Rockingham Jetty (approximately 40 km south of Perth via Kwinana Freeway). Multiple commercial tour operators offer sea lion, penguin, and dolphin encounters. Day trips only. Rockingham provides accommodation and full services.

The Australian sea lion population is declining nationally. On-water vessel regulations around Seal Island are critical to preventing disturbance to hauled-out sea lions. Dolphin interaction tourism requires strict protocols to prevent habituation-related harm. Phytoplankton blooms from nutrient enrichment can reduce water quality. The little penguin colony on Penguin Island requires fox and cat control on the adjacent mainland where birds forage.