The Grass Could Be Greener

Seagrasses are specialised marine plants critical to nearshore coastal environments.

They are vital sources of food and shelter and contribute to water quality through oxygenation, nutrient recycling and trapping of sediment and sand. Seagrass meadows are important breeding and nursery habitats for many marine organisms.

Seagrasses are flowering plants and their seeds are fertilised by pollen that is carried through the water. They may also reproduce by sprouting rhizome roots, meaning a single plant is capable of creating an entire meadow.

Seagrass meadows...

• Reduce the erosive impacts of wind and waves by stabilising the seabed
• Provide shelter for eggs and larvae to attach to, making them safe nursery areas
• Are critical food sources through not only their leaves and stems, but also the algae and bacteria that grow
• Improve water quality by absorbing nutrients and trapping sediments
• Provide food when they die for decomposers such as sea cucumbers, crabs, and worms, and help in stabilising sediment with their mattes and roots

It is important to know that these meadows actively reduce the effects of climate change and are shown to capture and store carbon 35 times more efficiently than tropical rainforests.

Seagrasses are often referred to as the 'lungs of the ocean', as just one square metre can produce up to 10 litres of oxygen per day through photosynthesis.

There are natural processes impacting seagrass survival, such as storms and sting-rays digging up roots while foraging, however the impacts of human activities account for the majority of the degradation.

The leading cause of seagrass death can be attributed to agriculture and industry in the high levels of nutrients in sewage and run off. Toxins and an excess of nutrients cause algal blooms and suffocation of the seagrasses due to insufficient light availability and poor water quality.

Other activities adding to decline include climate change, coastal development, dredging, anchorages, boat propellers, and the dragging effect of mooring chains.

In Derbal Nara (Cockburn Sound), around 85% of seagrass has been lost since 1967. Until relatively recently, industries had been continually dredging and discharging waste into the Sound. Oil refineries, sewage treatment, fertiliser production, and construction have had a colossal impact.

The Sound was once home to over 4000 hectares, but now less than a quarter of this remains.

The death of seagrass beds are far more than an aesthetic issue. The process releases large amounts of harmful carbon into the ocean and atmosphere, resulting in devastating impacts on marine habitat and food sources.

In short, local fish, mammals, turtles, and molluscs, either die or are forced to move away in search of new homes.

The ecosystem collapses.

Given that seagrass is being lost at a far higher rate than it is being restored, conservation is a difficult but essential and productive task. Basically, something that is conserved does not need to be restored. Natural recovery is slow due to poor conditions or degraded environment and human intervention is key to countering the damage humans have caused. Seagrasses take decades to be restored after destruction, so there is a great need for increased funding and active support to avoid the reality or even perception of failure in the process.

"Restoration of seagrasses is not a quick fix, thus not a politically acceptable fix." - Professor Gary Kendrick, UWA

Now, scientists have turned to the local community.

A collaboration between the University of Western Australia and  OzFish   has seen the development of the community-based seagrass restoration project  Seeds For Snapper  . The project relies on volunteers from the local community in the collection and dispersal of seeds to empower the regrowth of disturbed or destroyed seagrass meadows.

The initiative reinforces the crucial link between seagrasses and marine fauna – that we cannot have one without the other. Bringing together scientists, snorkelers, recreational fishers, divers and beachgoers, raises awareness and cultivates a sense of community and ownership, encouraging public engagement in the conservation and protection of life in local waters.

The results are promising!

Well over a million seeds have been collected by  Seeds For Snapper  participants, with growing numbers of participants donating their time and effort at all stages.

Professor Gary Kendrick and his team from the University of Western Australia are currently facilitating programs in Gathaagudu in which Malgana youth and community members are provided with the skills to promote successful seagrass restoration in the region. He emphasises the importance of supporting Indigenous communities in their growth, and seeking – from a conservation perspective – active involvement in the hands-on work and decision-making from community members.

Western methods have much to gain by partnering with Traditional land management methods, with historical insights and interpretations adding to our understanding of the biological, physical, and spiritual environments in which we live.

While some community-based restoration projects are up and running, there is still much to do.

You can volunteer your time to collect and disperse seagrass seeds with projects such as  Seeds For Snapper , and get involved with other events in your community. Tell your family and friends! Share this story and talk about marine habitats in your local area and what is being done to conserve them.

If you live in Perth, follow  Seeds For Snapper  for updates on how you can be involved.