Seaweed Aquaculture in Australia

Published: 9 December 2022 Updated: 1 March 2024

Table of contents

Overview

There is increasing interest in Australian seaweeds for both ecological and commercial value.

Seaweed is a common term for aquatic marine plants that includes both seagrasses and macroalgae (as opposed to microalgae). Algae is the general term applied to types of aquatic plants.

There are three main types of macroalgae: green, red, and brown. Australia has thousands of different algal species. In Southern Australia, about 60 per cent are endemic (found only in this part of the world).

Seaweeds play an important role in marine systems. They provide food and habitat for other aquatic life, absorb nutrients, and reduce wave impacts.

Seaweeds also have commercial value. Asparagopsis (red algae), Giant Kelp (Macrocystis species), various species of Gracilaria (red algae), Ecklonia (brown algae) Ulva (green algae) and Undaria (brown algae) are currently being researched and trialled for commercial production. There are also several other species with commercial potential as part of multi-trophic aquaculture with finfish culture. There is considerable effort in restorative aquaculture to restore seagrass beds and kelp rocky reed communities. The Commonwealth Government is currently in the process of establishing Australia’s first national environmental-economic accounting focussed on blue carbon credits to demonstrate the financial values of ecosystem services and the biodiversity benefits that result from restoring blue carbon ecosystems like seagrass beds.

Seaweed aquaculture

Seaweed aquaculture in Australia is a promising industry with a wide range of potential uses such as food, animal feed, biofuels, and fertilizers. Seaweed can be grown both on land and at sea, with minimal environmental impact. Despite being historically used by Indigenous Australians, Australia's commercial seaweed production currently lags behind other countries like Asia, Europe, and America. Australia's coastal waters have thousands of native seaweed species, many of which show promise in various markets. Of particular significance is the native genus of red seaweed Asparagopsis, which can be used to reduce methane emissions when used as animal feed. There are also significant projects currently underway around Australia looking at other species for use as a food source (Ecklonia spp, Macrocystis, Ulva spp, Undaria spp, Durvillea spp), bioremediation accelerant (Ulva, Sargassum spp), restoration work (Phyllospora spp) and fertilsers (Durvillea spp).

Building the supply chain of producing, processing, and consuming seaweed products has the potential to create jobs, improve the diets of Australians, and protect Australian ecosystems.

Asparagopsis aquaculture

Asparagopsis is a red macroalgae which contains chemicals that inhibit fermentation within the gut of cattle. When fed as a supplement to cattle it can reduce their methane emissions by 90 per cent or more. This is a significant benefit to agriculture, given around 10 per cent of greenhouse gas emissions in Australia come from the digestion process of cattle.

The commercial seaweed farming industry in Australia is rapidly expanding, with companies harvesting Asparagopsis from marine and land based farms for agricultural use in Tasmania, South Australia, and Western Australia. Further rapid growth in the aquaculture of this species is being driven by the Commonwealth Government's recent commitment to reduce methane emissions by 30% below 2020 levels, leading to increased private and public investments to overcome production bottlenecks and boost output.

Research priorities

A Blueprint for the Australian Seaweed Industry (Blueprint for Australian seaweed industry | FRDC) has a number of key research and development priorities, including;

Acceleration of Asparagopsis cultivation
Developing integrated multitrophic aquaculture with kelp farming
Bioremediation/biofiltration in catchments for the GBR and on land aquaculture facilities
Expanding the variety of species of seaweeds currently being farmed to include species that are of particular interest as a human food source
Developing regional plans for the industry
Developing a National Hatchery Network
Offshore seaweed aquaculture

Research is currently co-ordinated across the following research providers FRDC, Marine Bioproducts CRC (Program 1 - MB-CRC (mbcrc.com), Blue Economy CRC (Seafood & Marine Products | BE CRC Research Program (blueeconomycrc.com.au), ACIAR (Fisheries (aciar.gov.au)) , Agrifutures and the CRC for Northern Australia (Developing Asparagopsis seaweed cultivation at scale in Northern Australia | CRCNA).

Contacts

Jo Kelly, Australian Seaweed Institute, jo.kelly@australianseaweedinstitute.com.au
Wayne Hutchinson, FRDC, Wayne.hutchinson@frdc.com.au
Catriona MacLeod, University of Tasmania (Marine Bioproducts CRC)