red feather algae with finely divided fronds in the surge zone
- Size
- Height: 10–25 cm
- Lifespan
- 1–3 years
- Diet
- Grows on rocky reefs in low intertidal and shallow subtidal zones of clear, sheltered waters. Requires clean water, stable rock surfaces, and good water flow. Tolerates sun, moderate wave action, and temperature fluctuations. Forms fine, feathery, branching fronds that look like tiny red feathers or delicate plumes. Beautiful, but not from here. Slightly invasive, and definitely persistent.
- Habitat
- The red feather algae grows on rocky reefs throughout New Zealand – from the Three Kings Islands down to Stewart Island, in the low intertidal and shallow subtidal zones. It is a creature of the clear water, the sun-dappled reefs, the places where the light filters through. It forms fine, feathery, branching fronds that look like tiny red feathers or delicate plumes. It is beautiful, but it is not from here. It is slightly invasive, and it is definitely persistent.
- Range
- New Zealand - found throughout the North and South Islands on rocky reefs in low intertidal and shallow subtidal zones of clear, sheltered waters. Most common in the North Island and northern South Island. Native to Australia and New Zealand (some debate), but has spread to other parts of the world where it is considered invasive. Forms fine, feathery, branching fronds that look like tiny red feathers or delicate plumes.
- Endemism
- Native
- Main Threats
- None significant - this species is common and widespread. Localised threats include coastal development, pollution, and climate change affecting water temperature. Classified as Not Threatened, but potentially problematic as it has spread to other parts of the world where it is considered invasive. Native to Australia and New Zealand (some debate), beautiful but definitely persistent.
- Population
- Not Threatened, but potentially problematic. Red feather algae is native to Australia and New Zealand, but it has spread to other parts of the world, where it is considered invasive. In New Zealand, it is common on rocky reefs throughout the country. It is not rare. It is just very, very feathery and very, very persistent.
- Conservation Status
- Not Threatened
The beautiful one. An alga that looks like a feather.
Its fronds are fine, feathery, and branching – like tiny red feathers or delicate plumes. The colour is a bright pinkish-red, sometimes with purple highlights. The fronds are soft and flexible, waving gently in the current. It looks like something that might be worn in hair, not something that grows on a rock. An alga that belongs in a craft shop.
What makes it special? The persistence. The red feather algae is a survivor. It grows on rocky reefs, on shells, on other seaweeds. It can tolerate a wide range of conditions – from sheltered bays to exposed coasts, from low light to bright sun. It reproduces by releasing spores and by fragmentation. A tiny piece broken off can grow into a whole new plant. It is the weed of the reef, the one that keeps coming back. An alga that refuses to die.
The red feather algae has a secret weapon. It produces chemicals that deter grazing by fish and sea urchins. These chemicals also have anti-bacterial and anti-fungal properties. The algae is being studied for its potential use in medicine and agriculture.
Biologically, the red feather algae is a red alga. It has a complex life cycle, alternating between a large, feathery stage and a small, crustose stage that grows on the surface of shells.
The reef is shallow. The red feather waves in the current, pinkish-red and delicate. A sea urchin approaches, then turns away. The chemicals warn it off. The alga does not know it is being studied for medicine.
It just wants to not be eaten.