New seagrass restoration project underway in Western Australia
Seagrass for Swimmers is the new seagrass restoration project on the block, looking to revitalise seagrass meadows in Leschenault Estuary and bring back essential habitat.
Environmental conditions led to significant seagrass losses in the Leschenault more than a decade ago, and although some recovery has occurred, the ecosystem is not as robust as it once was. The innovative seagrass trials aim to improve density of seagrass and in turn the estuary’s health, which will provide nursery areas, feeding grounds, and shelter for the blue swimmer crabs and fish that call it home.
Through its Seeds for Snapper program, OzFish has been deeply involved in seagrass restoration efforts in metropolitan Western Australia since 2018. Shifting our focus to regional estuaries, this initiative, in partnership with Leschenault Catchment Council, the Western Australian Department of Water and Environmental Regulation (DWER), and the University of Western Australia, aims to investigate optimal methods for cultivating Halophila ovalis in the estuary.
Halophila ovalis, commonly known as paddleweed due to its paddle-shaped leaves, is one of the smallest species of seagrass. It is a flowering plant that produces tiny fruits that can hold up to 20 seeds each. It is an ideal species to be used for the restoration trials as it exists in many estuarine and marine systems in WA, is fast-growing and can establish meadows quickly.
OzFish WA and the DWER seagrass team started the project at the end of February with the collection of Halophila samples from 5 different sites in the estuary. Local students from Manea College became citizen scientists and were recruited to help process the samples in the lab. Students identified male and female flowers, fruit, and growing tips, as well as practising their classification skills with the invertebrates found in the sediments. Data collected will help identify which sites will be best for future seed collection.
Like other flowering plants, seagrass does not produce fruit all year round, and as summer draws to a close and cooler weather sets in, there is limited fruit left to collect. The next step in this project will involve collecting seagrass fragments to investigate the viability of rhizome material in the restoration work. A few methods will likely be trialled in 2025, including seed dispersal, sediment transplants and fragment collection.
To find out more about the project, head to the Seagrass for Swimmers project page.
