Mangrove forests are among the world’s most productive ecosystems and healthy mangroves are a precious, almost priceless resource. Mangroves can quite literally save lives during storms and extreme weather events but losing mangroves also means losing livelihoods, food security, valuable timber production, coastal erosion defence and one of the most efficient and important carbon stores on the planet.
Pacific Reef Fisheries’ story…
In Australia’s tropical north Queensland adjacent to the sparkling waters of the Great Barrier Reef marine park, lies Pacific Reef Fisheries. The Australian owned and operated business focuses on the sustainable production of more than 1000 tonnes of farmed black tiger prawns each year.
But the real success story of Pacific Reef Fisheries is two fold; the way in which it has used the abundance of naturally occurring mangroves that surround the farm to sustainably and naturally filter water, and through the development of macroalgae technology used to clean aquaculture wastewater.
Natural filtration system
Wayne Di Bartolo is the farm’s Product Operations Manager and said Pacific Reef Fisheries worked to establish 23 hectares of mangrove forest on the farm site in order to naturally clean the water used in the shrimp ponds before it flows back to the Great Barrier Reef marine park.
“Our wetland is in its twentieth generation and was established as part of Pacific Reef Fisheries bioremediation system,” Mr Di Bartolo said.
“This system not only helps remove nutrients and solids from our discharge waters, it is a valuable ecosystem nursery for many native fish and crustacea. It is also home to many native birdlife and a stopover for many migratory bird species.”
The filtration system works in four stages to sustainably treat wastewater; water leaves the production ponds, passes through a settlement system and finally through the constructed mangrove wetland before entering the environment.
The farm’s parent company Pacific Biotechnologies, together with James Cook University, have developed world-leading water treatment technology, RegenAqua, that uses macroalgae and sand filtration to naturally remove nutrients from wastewater, allowing water to be released back into the environment with no net impact. It is this technology that sets Pacific Reef Fisheries apart from all other aquaculture operations.
“We also use this breakthrough technology to create nutrient rich products for plants and animals,” Mr Di Bartolo said.
The entire farm site spans 370 hectares of which 98 hectares is licensed for production. When establishing the wetland system, Mr Di Bartolo said the farm was granted a permit by the local government to remove some plants and, more importantly, collect cuttings from the surrounding environment for planting in the constructed bioremediation system.
Such is the success of the project that internal studies by the farm have revealed there is approximately 4000 tonnes of biomass in the constructed wetland and self-seeding means it will continue to naturally flourish into the future.
By using the mangroves that thrive in abundance on the site, Pacific Reef is able to release water back into the environment that meets regulatory requirements which is especially important given the adjacent marine park. Such is the efficiency of the mangroves as a water filtration system that Mr Di Bartolo said it is not unusual for the water leaving the farm site to be of better quality than when it entered the site.
- This is part of a series of blogs exploring how ASC certified farms are helping protect vital mangroves. Read the first blog, about Omarsa in Ecuador.