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What do rats have to do with the number of fish on coral reefs?
The Black Rat – Rattus rattus – wreaks havoc on island seabirds around the world, including in the Great Barrier Reef, where it has been harmful for over 200 years.
Animals eat breeding bird eggs and attack young, removing the number of birds on the islands that they inhabit.
An article in Nature Today shows how this triggers a series of events that not only damage the surrounding coral reefs. but also has an impact on fish and other forms of marine life.
It's all about poo.
Researchers found that fish biombad was much higher on reefs around rat-free islands.
(Provided: Nick Graham)
" So you really could not conceive of the experience much better. "
Dr. Hoey was part of a team that compared the abundance of aberrations and nitrogen levels in the soil between rat-infested and rat-free islands.
the rats were absent, they found that the abundance of seabirds was 760 times greater than on the islands with rats.
As a result, the rates of nitrogen deposition of the poop of birds, known as guano, were 251 times higher.
The impact of rats extends to external reefs
Birds are an important source of new nutrients for isolated islands
"The most important thing for seabirds is that they travel offshore and bring these ocean sources of nutrients to the islands," says Dr. Hoey
The reduction of nutrient concentrations had an effect on reef ridges
(Provided: Nick Graham)
Reduced levels of nutrients had an effect on reef ridges
Researchers have specifically studied nitrogen-delta-15, which is present in seabird droppings and can be traced back to their oceanic regime.
Rats eat eggs and young birds
(Provided: Nick Graham)
Black rats have wiped out many species of birds on Lord Howe Island
(Getty: Michael Leach)
A rat-baiting project
(Source: Sarah Oxenham)
A rat-baiting program on the island Lord Howe divided opinions
In 1964, climber and scientist David Roots discovered Lord Howe's stick-shaped insect, which we thought was extinct, on a rocky outcrop about 30 kilometers from the island
. reintroducing the stick insect, known as the Lord Howe tree lobster, is approaching a start date.
The plan would see tons of poisoned pellets dropped from the helicopter and hand-held on the almost virgin island.
Bird droppings or guano provide high levels of nitrogen to island ecosystems
(Provided: Guy Stevens)
Bird droppings or guano provide high levels of nitrogen to island ecosystems
It has been proven that the local population feared that the poison could affect them. Other native wild species.
Researchers will follow the program closely. If it works, it could serve as a model for similar projects in other Australian islands
In the case of uninhabited islands, the removal of rats should be a conservation goal in the near future, according to Dr. Hoey . "There is more and more evidence, like on the island of Macquarie, near Antarctica, where they have also managed to eradicate rats and foxes," he said.
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Tags coral fish havoc News number Rats reduce reefs Science wreak
