Seaweeds

Golden Kelp

Ecklonia radiata

A foundation of the Great Southern Reef, golden kelp forms underwater forests that provide food and shelter for an extraordinary variety of marine life.

Scientific Name

Ecklonia radiata

Group

Brown algae

Habitat

Temperate rocky reefs

Energy Source

Photosynthesis

Ecological Role

Habitat forming seaweed

Ecology

The living foundation of the reef

Golden kelp is one of the most widespread habitat-forming seaweeds along Australia’s temperate coastline. Its forests turn rocky seafloors into living habitat, providing shelter for fish and countless smaller animals.

As a brown alga, it captures sunlight through photosynthesis and absorbs nutrients directly from seawater. This productivity helps fuel the food webs of the Great Southern Reef.

Structure & Identification

Built for the canopy

Look for a sturdy stipe and a broad central blade edged with smaller, strap-like blades. Golden kelp’s leathery surface often has a distinctive rippled or pitted texture.

01 Holdfast

A branching anchor grips the rock. It holds the kelp in place without drawing nutrients from the reef.

02 Stipe

A strong, stem-like support connects the holdfast to the broad frond above.

03 Blades

The central blade and its flat side blades capture sunlight and absorb dissolved nutrients.

04 Texture

Golden-brown, leathery tissue often has a pitted surface and small projections along the edges.

Distribution & Habitat

Golden kelp occurs around southern Australia, including Tasmania, and extends north along both the western and eastern coasts. It grows attached to submerged rocky reefs, wherever light and local conditions support its growth.

Forests along our southern coastline

Hard surfaces give holdfasts a secure place to attach.

•Rocky Foundations

•Light Beneath the Surface

Water clarity helps determine how deep kelp can grow.

•A Changing Coastline

Forest structure varies between places and conditions.

Range and habitat: DBCA species profile; Deakin University.

Why it matters

A Forest full of life

From the holdfast to the moving canopy, golden kelp adds structure to the reef. Fish, crustaceans, molluscs and other seaweeds use the spaces it creates.

Living kelp and detached fragments support coastal food webs.

•Food for the coast

Blades and holdfasts provide habitat for animals of many sizes.

•Shelter at every scale

•Connected Communities

Healthy kelp habitats support fisheries, diving and our connection to the sea.

Threats & Resilience

When the forest disappears

Golden kelp forests face pressure from ocean warming and excessive grazing. Where kelp is lost, the change reaches the many species that depend on its habitat.

Higher temperatures and marine heatwaves can stress kelp and affect its survival.

• Warming Seas

Abundant sea urchins can strip reefs of kelp, leaving persistent barrens.

•Too Much Grazing

Recovery Takes more than Planting

Reducing the pressures that caused a forest’s decline is part of helping it return.

Research: warming and kelp recovery; Port Phillip Bay restoration report.

Restoration case study

In Port Phillip Bay, researchers and restoration teams are helping golden kelp return to degraded reefs. The work combines managing overabundant sea urchins with growing and planting young kelp.

One approach, known as green gravel, starts with cultivating kelp on small stones before placing them back on the reef. Seeded twine and transplanted kelp provide other ways to help forests re-establish.

The 2022–2025 collaboration brought together The Nature Conservancy Australia, Deakin University, the University of Melbourne and Parks Victoria. Monitoring recorded more kelp recruits and adult kelp in restored areas than in untreated barrens.

Growing the next Generation

Source: Port Phillip Bay Golden Kelp Restoration Project, summary report (2026).

Continue Exploring

  • Seaweeds

    Meet the marine algae that help shape the Great Southern Reef.

    Explore Seaweeds

  • Kelp Forests

    Kelp forests form the living foundation of the Great Southern Reef, creating food, shelter and nursery habitat for an extraordinary diversity of marine life.

    Explore Kelp Forests

  • Citizen Science

    Get involved and help researchers better understand and protect the reef.

    Find A Project

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