<
https://www.sciencealert.com/scientists-discover-a-giant-manta-ray-population-10-times-bigger-than-any-other>
'With so many species under threat due to human activity and climate change,
it's encouraging to hear about one population that's doing very well for
itself: a group of more than 22,000 oceanic manta rays (
Mobula birostris) off
the coast of Ecuador.
That estimated population size is more than 10 times the numbers thought to be
in other regions, and conservationists are hoping that this "unprecedented"
community of manta rays can offer some clues about the conditions that the fish
find favorable.
In 2019, oceanic manta rays were reclassified as endangered on the IUCN Red
List of Threatened Species, with commercial fishing the largest threat to the
species – whether that's through direct targeting or unintentional bycatch.
"It's clear that something different is happening here," says quantitative
ecologist Joshua Stewart, from Oregon State University. "This is a rare story
of ocean optimism. In other regions, we typically have population estimates of
1,000 to 2,000 animals, which makes this species very vulnerable."
While it's clear oceanic manta rays are vulnerable, it's not easy to study and
monitor these animals: they spend a lot of time in hard-to-access offshore
locations, and their patterns of movement can be unpredictable as well.
Since the late 1990s, scientists have been keeping tabs on this particular
group of manta rays in coastal Ecuador. For this latest estimate, researchers
used more than a decade's worth of photos and observations taken out in the
field between 2005 and 2018 to estimate a current population of above 22,000.'
Via Rixty Dixet.
Cheers,
*** 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
