Algae

Algae in Victoria: Cultural Use, Ecology, and Environmental Change

MLA Educational Series — Water, Ecology, and Culture

Algae — encompassing microscopic phytoplankton to towering seaweeds — are ancient life forms central to Victoria’s aquatic ecosystems. For Indigenous peoples, algae were not simply plants, but part of a living aquatic network connecting water, food, and spirit. Before colonisation, rivers, wetlands, and coasts thrived in balance, with algae sustaining eels, fish, waterfowl, and human communities. These systems provided both nourishment and ecological indicators that guided seasonal movement and ceremony. Colonisation, however, disrupted this equilibrium through deforestation, river regulation, and pollution, producing algal blooms and degrading ecosystems that once sustained Indigenous life.

Algae and Indigenous Knowledge in Victoria

Food and Medicine

Along the coastlines of Wadawurrung, Boon Wurrung, Gunditjmara, and Gunaikurnai Country, certain seaweeds and green algae were eaten fresh, dried, or added to stews as nutrient supplements rich in minerals such as iodine and calcium (Clarke 2009). Laminaria and other kelps, collected during low tide, were occasionally used as food and to treat skin and digestive conditions.

In inland areas — including Wurundjeri and Taungurung Country — green algal mats and aquatic plants were gathered from river margins and billabongs, sometimes dried or boiled as medicinal infusions. Algae also formed part of larger aquatic systems that sustained culturally important plants such as cumbungi (Typha spp.), water ribbons (Triglochin spp.), and nardoo (Marsilea drummondii) (Gott 2019; Museums Victoria 2023). Together these species provided carbohydrates, fibre, and nutrients that underpinned Indigenous food economies.

Technology, Ceremony, and Cultural Roles

Dried seaweed and algal mats served multiple purposes — insulation for coolamons, wrapping material for food storage, and packing for shellfish preservation on coastal journeys. In ceremony, aquatic vegetation signified renewal and fertility, reflecting the constant movement of water and life.

Algal patterns and water clarity were also read as spiritual messages. A sudden bloom or discolouration could indicate ecological imbalance or the displeasure of ancestral water beings, guiding communities to observe cleansing or offering rituals. Seasonal changes in algal growth marked the times for eel migration, shellfish collection, and fish spawning, forming part of cyclical calendars across Victoria (Howitt 1904).

Wadawurrung and Victorian Indigenous Examples

Across Wadawurrung Country — from the Moorabool and Barwon Rivers to Lake Connewarre and the Bellarine wetlands — algae were part of a living aquatic economy. Green and filamentous forms grew alongside eel channels and water-ribbon beds, supporting the productivity of seasonal fish and eel harvests.

On Gunditjmara Country, at Budj Bim, algae sustained the eels within the aquaculture systems, forming the base of a complex, engineered food web that operated for millennia. For Wurundjeri peoples along the Birrarung (Yarra River), clear, balanced water with moderate algal growth indicated ecological health and was tied to ceremonial obligations of care for waterways. Among Gunaikurnai peoples, kelp and seaweed were used in both practical and symbolic ways along the Gippsland coast — dried for wrapping fish and referenced in stories of sea spirits and tides.

These interwoven relationships reveal that algae were understood not as passive vegetation, but as living signs of Country’s well-being.

Ecological Role of Algae

Algae form the foundation of aquatic life in Victoria:

• Primary producers: Through photosynthesis, algae generate oxygen and convert sunlight into the energy that sustains aquatic food chains.

• Habitat and shelter: Kelp forests along Victoria’s southern coast provide refuge for abalone, fish, and crayfish (CSIRO 2020).

• Nutrient cycling: Freshwater algae recycle nutrients in rivers and wetlands, balancing ecosystems that support culturally important species such as short-finned eel (Anguilla australis).

• Biodiversity and aquaculture: The Budj Bim eel traps, among the oldest engineered systems on Earth, relied on healthy algal growth to sustain food webs and maintain water quality.

In essence, algae connected light, water, and life — their presence ensuring the productivity of ecosystems that nourished both nature and people.

Environmental Change After Colonisation

River Regulation and Habitat Loss

Colonisation brought massive ecological change. Dams, drainage, and channelisation destroyed wetlands that once filtered water and maintained algal balance. The clearing of riparian vegetation allowed sediment and nutrients to flood waterways, creating conditions for eutrophication and toxic cyanobacterial blooms (MDBA 2021).

Agriculture and Urbanisation

Runoff from fertilisers and wastewater accelerated nutrient loading, turning rivers like the Murray, Loddon, and Campaspe into bloom-prone systems. Blooms depleted oxygen, suffocated fish, and made water unsafe for cultural use and ceremony.

Marine Decline

Along the Victorian coast, climate change and invasive species (particularly sea urchins) have devastated giant kelp forests, with more than 90% lost in some regions (CSIRO 2020; Victorian Fisheries Authority 2022). The collapse of kelp beds disrupted shellfish populations, damaging both ecosystems and traditional harvesting practices of coastal Indigenous communities.

Cultural Disconnection

As waterways became polluted and blocked, Indigenous communities lost physical and spiritual access to eel and fish grounds. The seasonal cues once read in algal patterns faded under altered flow regimes and water quality decline, fracturing ancient systems of ecological knowledge.

Revival, Research, and Restoration

Ecological Renewal

Wetland rehabilitation projects — such as those at Western Treatment Plant, Lower Yarra wetlands, and Gippsland Lakes — are rebalancing nutrient levels and re-establishing algal diversity. These efforts restore not just water quality, but the ecological foundations of Country.

Cultural Renewal

Indigenous-led waterway management programs increasingly integrate cultural perspectives. Traditional Owners Corporations across Victoria — including Wadawurrung, Wurundjeri, Gunaikurnai, and Gunditjmara — are reasserting roles in river and coastal management, reconnecting community, ecology, and spirit.

Science and Indigenous Knowledge

Modern ecology now recognises what Indigenous systems long understood: algae are keystone producers that balance aquatic life. Collaborative research between Traditional Owners and scientists explores the potential of sustainable seaweed harvesting for food, medicine, and blue-carbon capture, positioning Indigenous communities at the forefront of ethical environmental enterprise (CSIRO 2020).

The Future of Algae in Victoria

Algae embody both fragility and power. When ecosystems are healthy, they sustain abundance; when disturbed, they signal imbalance. Protecting algal diversity requires reducing nutrient runoff, restoring wetland buffers, and adapting to climate change. Culturally, reviving Indigenous ecological knowledge ensures that algae regain their rightful place within Country’s living systems — as indicators, teachers, and ancestors of water. The future lies in uniting science and story, law and ecology, to restore balance to Victoria’s rivers, wetlands, and coasts.

Conclusion

In Victoria’s Indigenous cultures, algae were never separate from life — they were part of the cycle of nourishment, ceremony, and observation that sustained Country. They fed eels, stabilised wetlands, and mirrored the rhythm of seasons. Colonisation disturbed this harmony, but today’s restoration and cultural renewal efforts reaffirm the wisdom that balance begins with the smallest forms of life. Protecting algae is not only about water quality; it is about respecting the deep-time relationships between light, water, and living Country.

References

Clarke, PA 2009, Australian Aboriginal Ethnobotany: An Overview, CSIRO Publishing, Melbourne.
CSIRO 2020, The State of Australia’s Kelp Forests, CSIRO Oceans & Atmosphere, Hobart.
Gott, B 2019, The Yam Daisy: A History of Aboriginal Plant Use in Victoria, Aboriginal Studies Press, Canberra.
Howitt, AW 1904, The Native Tribes of South-East Australia, Macmillan, London.
MDBA (Murray–Darling Basin Authority) 2021, Blue-Green Algae in the Murray–Darling Basin, Canberra.
Museums Victoria 2023, Aboriginal Plant and Waterways Collections, Museums Victoria, Melbourne.
Victorian Fisheries Authority 2022, Coastal and Marine Ecosystems of Victoria, VFA, Melbourne.

Written, Researched and Directed by James Vegter (22 September 2025)

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Magic Lands Alliance acknowledges the Traditional Owners, Custodians, and First Nations communities across Australia and internationally. We honour their enduring connection to the sky, land, waters, language, and culture. We pay respect to Elders past, present, and emerging, and to all First Peoples’ communities and language groups. This article draws only on publicly available information; many cultural practices remain the intellectual property of their respective communities.