Picture yourself in an underwater garden in glorious technicolour: Orange and yellow sponges and sea squirts, pinkish-cream cauliflower soft coral, and ruby-hued sea fans in delicate lace clinging to the rocky reef. Octopuses and sea stars are nestled among them, while schools of silver and zebra-striped fish dart by, and wobbegongs, sea turtles and sapphire-like giant blue gropers move with slow grace. Golden kelp forests sway, sheltering weedy sea dragons, lobster and abalone.When you surface and look to the east, you might see a visiting dolphin or whale. But look to the west, and you will see the cranes and colourful shipping containers of the port of Botany.For Sydneysiders thinking about what makes their city beautiful, the Sydney Harbour and ocean beaches often spring to mind. They usually overlook Sydney’s second harbour – Botany Bay, or Gamay.ai2html:gamaybotany; size: largeYet, despite the ravages of industry and urban development, Botany Bay has retained pockets of surprising beauty.Today, a movement led by the Aboriginal community at La Perouse is bringing Gamay back to life by protecting and restoring its ecosystems and linking with similar efforts to revive the Cooks River that flows into the bay.Indigenous rangers, along with state and local government, leading scientific institutions and supportive individuals and businesses, are replanting seagrass meadows, building new oyster reefs, reintroducing seahorses, and studying marine mammals in the bay.paragraphtitle: Overlooked beautyRobert Cooley, also known as Bintar, was born in the La Perouse Aboriginal community. Growing up in the 1970s, Cooley spent nearly every day of his childhood swimming and fishing at places such as Frenchmans Beach and Yarra Bay.“What kept me sane and healthy throughout my life was knowing that I had the ocean to be in, on, around and under,” says Cooley, 59. “Over time as the ocean has become less healthy, it’s been less enticing for the kids.”There are about 300 people living in the La Perouse community, Cooley says, but 1500 people with strong connections to it, mostly living nearby in the eastern suburbs.https://thearticlestack.com/interactive/modules/multimedia-gallery/index.html?resizable=true&v=538&configUrl=https://thearticlestack.com/interactive/hub/configs/multimedia-gallery/53186.json&v=0.671407922938919; size: large;He helped found the Gamay Rangers in 2019 to give his people a voice in the management of the bay and tackle the environmental degradation that was disconnecting the young people in his community from healthy activity and cultural practice. The flathead and blue swimmer crabs that Cooley grew up catching were becoming scarce, and no one seemed to know why.Funded through the Commonwealth Indigenous Rangers program, Gamay Rangers now employs eight full-time rangers, plus one casual, and has its fingers in multiple research and restoration projects through collaborations with scientists.For example, the team is working closely with Dr Vanessa Pirotta from Macquarie University to study the whales, dolphins and seals that frequent the bay, including collecting data to recognise individual dolphins by their dorsal fins.ai2html:reserves-estuaries; size: largeThe Gamay Sea Country Plan released last year sets a course for the next decade, covering everything from stormwater management to irresponsible jetski use.Cooley often takes people – from friends to government officials – for coastal walks, and finds they are usually surprised by how lovely it is.“People are focused on Sydney Harbour … and I don’t think most people know too much about the beauty of Botany Bay,” Cooley says.“Despite our best efforts to destroy the place in the last 250 years, for whatever reason it’s hung on – not everywhere, but in patches, and we’ve got to try to protect those places that are still beautiful and natural.“We know what was and what is, but we also know what we need to do, by working with scientists, to get towards what was once here.”paragraphtitle: An impressive harbourGamay provided food, shelter and culture to its traditional owners for millennia, as evidenced by the middens, burial grounds and birthing trees scattered around the bay.The harbour also greatly impressed the British when James Cook, captain of the Endeavour, arrived in 1770 and landed on the eastern end of what is now Kurnell. The ship’s botanist, Joseph Banks, famously went on to recommend Botany Bay as the site for a colony.https://thearticlestack.com/interactive/modules/multimedia-timeline/index.html?resizable=true&v=195&configUrl=https://thearticlestack.com/interactive/hub/configs/multimedia-timeline/52142.json&v=0.4247831213109241; size: large;Cook first called the bay Sting-Ray Harbour, but Banks was so excited by the diversity of fauna and flora that they changed it to Botanist’s Bay, before eventually settling on Botany Bay. Now the traditional name of Gamay or Kamay is also officially recognised.Essentially a flooded river valley, Gamay is much shallower than Sydney Harbour, naturally between five and 14 metres deep, though there is extensive dredging to allow for shipping. There is a one-kilometre opening from Cape Banks on the north shore to Cape Solander on the south. The bay spans 40 square kilometres, fed by the heavily degraded 23-kilometre Cooks River and the larger Georges River, which runs for 96 kilometres and is under increasing pressure from urban development.paragraphtitle: Quickly industrialisedAlthough the First Fleet ultimately landed further north at Port Jackson (better known as Sydney Harbour), Botany Bay was industrialised almost immediately.“Shortly after settlement, they needed a source of lime to use as mortar, so they took a lot of the molluscs – bivalves – out of the bay in the early 1800s,” says Dr Pat Hutchings, senior principal research scientist at the Australian Museum.Later, the entrance to the Cooks River was rerouted to build Sydney Airport. The construction of Port Botany changed the direction of the waves, destroying seagrass meadows and encouraging the growth of mangroves on former salt marsh. The bay was repeatedly dredged for shipping or construction of industry such as the oil refinery in Kurnell. Industry discharged effluent into the bay and oil spills were a regular occurrence throughout the 20th century.https://thearticlestack.com/interactive/modules/multimedia-gallery/index.html?resizable=true&v=212&configUrl=https://thearticlestack.com/interactive/hub/configs/multimedia-gallery/53116.json&v=0.8405677852914074; size: large;Even now, the extent of development in south-western Sydney means the wastewater overflow site at Mill Pond frequently spills over when it rains, flooding the bay with raw sewage.Despite that, sites such as Bare Island, Henry Head and The Steps in Kurnell are prized for some of the best diving and snorkelling in Sydney, while the wetlands at Towra Point are internationally significant.Overall, Gamay-Botany Bay remains on par with Sydney Harbour for biological diversity, scientists say.paragraphtitle: Documenting diversityThe collection of the Australian Museum is vast, with 22 million items from gemstones to ancient artefacts. Only a fraction is on public display at any one time.Fortunately for Hutchings, most of the scientific collection is logged in a searchable database that includes parameters such as latitude and longitude.That allowed her to find all biological specimens from Gamay-Botany Bay going back to 1857, and answer the question: What do we already know about the ecology of Sydney’s second harbour?“Nobody had really pulled together the information that we currently have available on Gamay and yet a large part of Sydney’s population occurs around the foreshore and in the catchment of Gamay,” Hutchings says.Gamay has a wide range of habitats including seagrass meadows, kelp forests and other seaweed habitats, mangroves, salt marsh, soft sediments, sandy beaches, rocky shores and subtidal rocky reefs.Hutchings says Gamay has as much biological diversity as Sydney Harbour, with similar fauna. Yet, Sydney Harbour is two to three times deeper in parts and has more rocky shores and headlands, while Gamay favours muddy sediments, mangroves and flat, sandy beaches. Kurnell and surrounds have salt marsh, which in Sydney Harbour is only found up the Parramatta River in Homebush.Hutchings’ study, published in Australian Zoologist in 2025, focuses on marine invertebrates such as polychaetes (marine worms), crustaceans such as prawns, crabs and lobsters, molluscs such as snails, octopus, squid, mussels, oysters and clams, echinoderms such as starfish, sea urchins and sea cucumbers, and fish.Co-author Amanda Hay says there are also fish found in Gamay but not Sydney Harbour – such as red-fingered anglerfish found in rock crevices next to sponge gardens, red wide-bodied pipefish associated with a species of red algae, and also the long finger sponges.“There’s never been a record of a whale shark in Sydney Harbour, but we know that there’s a hard record of multiple sightings in Gamay,” Hay adds.paragraphtitle: Bringing back bivalvesThere is a healthy population of Sydney rock oysters at Towra Point west of Kurnell, but overall Botany Bay has lost 99 per cent of its Sydney rock oysters and 92 per cent of its flat oysters, scientists estimate. The rock oysters are submerged at high tide and exposed at low tide, while the flat oyster reefs are always underwater.“What we’ve lost there is really the kidneys of the ocean and estuaries,” says Andy Bossie, seascapes conservation officer at The Nature Conservancy. “A single mature flat oyster can filter up to a bathtub of water a day, so you can imagine, when that is scaled up to many thousands of oysters, the filtration potential is huge.”The oyster reefs also provide habitat, Bossie says. The Kurnell reefs, for example, are covered in kelp and support octopus, cuttlefish, pelagic fish such as leatherjacket and snapper, and smaller species such as shrimp and crabs.Back in 2023 the conservancy built six hectares of flat oyster reefs in Botany Bay. After a recent grant from the Australian government, the plan is to restore a further 2.5 hectares of flat oyster reef and half a hectare of rock oyster reef in the Georges River.Dr Mitch Gibbs, a senior lecturer at the University of Sydney, says it is important to also look at other bivalves such as pipis, scallops and mussels.“The whole point of ecosystem resilience is being able to have biodiversity, so when something changes, something else can take over,” Gibbs says.paragraphtitle: Releasing seahorsesAnother restoration focus is seagrass meadows, critical habitat for thousands of species. Seagrass is not a seaweed, but a flowering plant that evolved on land then moved back into the ocean.“They’re like the dolphins of the plant world, in the way that dolphins have a land ancestor and sea grasses have a land ancestor, and then they subsequently develop all the traits that allow them to survive fully on the water,” says Adriana Verges, a professor in marine ecology at UNSW and the Sydney Institute of Marine Science.Seagrass restoration makes possible the Sydney Seahorse Project, which involves the Gamay Rangers, the Sydney Institute of Marine Science, the University of Technology and the NSW government.Early this year, about 200 juvenile White’s seahorses bred in captivity will be released into Gamay, following previous releases in Sydney Harbour and Port Stephens. Special cages known as “seahorse hotels” will be installed next to the restored seagrass meadows to give the animals a structure to hold onto and protection from predators. Algae, sponges and soft corals will grow over the cages and form natural habitat as the artificial structures disintegrate.paragraphtitle: Seagrass restorationBotany Bay has lost half its historical seagrass coverage because of pollution, urban development and dredging, Verges says. Operation Posidonia aims to bring it back.At least once a week the Gamay Rangers collect fragments of seagrass that wash up on beaches. Veolia, the company that runs the desalination plant at Kurnell, has donated space for tanks where the fragments can be stored until there is enough to warrant a diving expedition to replant them.The seagrass is being replanted in Penrhyn estuary and in Kurnell, just west of Cooks landing site, and there are plans to do it in Frenchmans Bay and Yarra Bay. The long game, Verges says, is to switch to environmentally friendly boat moorings because the traditional design destroys seagrass as the chain drags on the ground.Of all the projects that the Gamay Rangers group is involved in, Cooley says the seagrass restoration is closest to his heart.“Last summer and this summer were the two biggest blue swimmer crab and flathead seasons that I can recall in three decades,” Cooley says. “I’m hoping that has something to do with the work we’re doing in restoring those seagrass meadows, given that’s their critical habitat. Time will tell and science will unlock the answer.”