Cleaner water is one of them
University of Melbourne
Researchers have identified 12 potential ecological benefits of aquaculture including species recovery, habitat restoration, rehabilitation and protection, and removal of overabundant species.
Aquaculture,
or the farming of aquatic plants and animals, contributes to biodiversity and
habitat loss in freshwater and marine ecosystems globally, but when used
wisely, it can also be part of the solution, new
research shows.
Published
today in Conservation Biology, University of Melbourne
researchers have identified 12 potential ecological benefits of aquaculture.
These include species recovery, habitat restoration, rehabilitation and
protection, and removal of overabundant species.
Lead
author, University of Melbourne researcher Ms Kathy Overton, said the potential
environmental benefits of aquaculture have gone under the radar for many years.
“Most people around the world live near freshwater or marine ecosystems, and we rely on them as sources of food, tourism, recreation, culture, and livelihood,” Ms Overton said.
“However,
our impacts on freshwater and marine ecosystems are degrading important
habitats and causing rapid declines in biodiversity. While the negative impacts
of some types of aquaculture are well known, we can also use aquaculture as a
tool to slow or stop these negative impacts and help restore ecosystems that
have been largely lost over the last century.”
Ms
Overton explained that millions of tonnes of fish, shrimp, shellfish and
seaweed are farmed for food each year, with some of this industrial production
providing benefits to the environment when farmed in a specific way or place.
“Seaweed
and shellfish farmed in coastal waters can remove excess nutrients coming from
urban or agricultural runoff and reduce the likelihood of toxic algal blooms
that kill fish and other native organisms,” she said.
In
addition, researchers found there are a range of new ways that conservationists
are tapping into aquaculture techniques to create new ways to restore or
conserve species and habitats.
“The
world’s largest conservation organisation, The Nature Conservancy (TNC), has
pioneered the use of aquaculture to restore lost marine ecosystems,” Ms Overton
said.
TNC
Australia Dr Simon Branigan said: “Aquaculture is a key part of our process to
rebuild lost shellfish reefs through creating healthy oyster and mussel
juveniles to kick start the reef restoration process.”
“Reefs
with abundant shellfish create strong ecological benefits – they are important
habitats for a host of marine species, and they improve water quality. Without
aquaculture, we would struggle to restore these lost marine habitats and get
this important conservation work done,” Dr Branigan said.
Aquaculture
is also used to help restore vulnerable or endangered fish populations around
the world, by ‘restocking’ cultured farmed fish back into their habitats.
“Species
recovery programs for fish such as the white sturgeon in North America, the
golden mahseer in India, and the Macquarie perch in Australia, are trying to
bring back wild populations and stop extinction,” Ms Overton said.
Co-author
and University of Melbourne researcher Dr Luke Barrett said aquaculture can
also be used to replace wild harvesting of threatened animals.
“Most
freshwater aquarium species are now farmed, which means that you can stock your
home aquarium without contributing to overfishing of vulnerable wild
populations,” Dr Barrett said.
“However,
many species in marine aquariums, like clownfish and corals, are still
collected from coral reefs for the aquarium trade. Researchers around the world
are developing methods to farm these species too, and ease some of the pressure
on wild populations.”
The
research team highlights the importance of using measurable indicators of
success.
Co-author
and University of Melbourne Professor Tim Dempster said: “By requiring a high
standard of evidence to label something ‘ecologically beneficial’, this reduces
potential for ‘greenwashing’, where aquaculture industries might claim to be
providing ecological benefits that aren’t really there.”
“We
want to ensure that aquaculture practitioners monitor their ecological impact
before claiming their farm creates ecological benefits. Just because a
particular aquaculture activity does one positive thing, it doesn’t mean that
it will deliver an overall benefit to the environment. It’s important to weigh
up overall impacts when deciding if something is ecologically beneficial or
not,” Professor Dempster said.
Researchers
say that as aquaculture expands in freshwaters and the ocean, there’s an
opportunity to avoid the mistakes people have made farming on land that have
led to habitat and biodiversity loss.
“We
want people to reimagine what aquaculture is and what it can do, and to show
people how it can be used as a tool to safeguard aquatic ecosystems and
biodiversity for future generations,” Professor Dempster said.