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https://theconversation.com/friday-essay-can-rewilding-offer-us-a-brighter-greener-future-281647>
"I’ve been fortunate to dive in Tasmania’s giant kelp forests over the past
three decades, launching into chilly waters. When diving in these forests,
light filters through the golden ribbon-like fronds in beams, lighting the
array of fish that sail through like birds in a rainforest. On the seabed,
pearlescent abalone shells shine and sunset-orange crayfish prowl, eyes agog.
Kelp forms a foundational part of the Great Southern Reef, which extends 8,000
kilometres around southern Australia from Kalbarri in Western Australia to
Coolangatta in Queensland. Here, for certain groups of organisms – seaweeds,
sponges, crustaceans, chordates, bryozoans, echinoderms and molluscs – as many
as 30–80% of species are found nowhere else on Earth. Think the weedy sea
dragon, for instance, with its leaf-like fins.
The region is a biodiversity hotspot, lesser known than the Great Barrier Reef,
but equally worthy. There are also commercially important species such as rock
lobsters and abalone that rely on healthy reefs for shelter and food.
Giant kelp is found in the southeastern corner of the Great Southern Reef. It
has historically been a tourism drawcard. Diving in giant kelp forests is like
being transported into the Jack and the Beanstalk fable – which is not really
an exaggeration, given its almost miraculous growth rate. Giant kelp can grow
50 centimetres a day in ideal conditions, reaching more than 30 metres from the
seafloor.
It used to choke boat propellers, hampering anchoring around Tasmania, but in
recent decades giant kelp has declined by 95% along the island’s east coast.
The reason for its demise: warmer, nutrient-poor waters extending further down
the Australian coastline than they once did, as well as the arrival of the
invasive long-spined sea urchin, which grazes on kelp and other seaweeds,
causing marine deserts called barrens.
In 2012, the giant kelp marine forests of southeast Australia became the first
marine community to be listed as endangered under the federal government’s
Environment Protection and Biodiversity Conservation Act.
My husband, Craig Johnson, a marine biologist, was one of the first to document
the decline and to think of rearing warm-tolerant giant kelp varieties and
reseeding them in the wild, through his work at the University of Tasmania’s
Institute for Marine and Antarctic Science.
Now, teams of researchers are working on just this, buoyed by the possibility
of restoring Tasmania’s iconic undersea forests. Trials have shown that giant
kelp forest can return in the space of a year.
So nature can heal if given a chance. The dream is that warm-tolerant strains
could be successfully reared and replanted at scale, and that these forests
would reseed more forests. If invasive urchins could be controlled, the barrens
could again be replaced by healthy temperate reefs."
Share and enjoy,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
