as a way to hopefully stave off our planet’s sixth mass extinction.

But there are a few tiny problems: we don't know exactly how many species exist, how many

are facing extinction, and how many we could actually save.

The reason?

There's no standard way to measure biodiversity and we’re missing a lot of data.

In recent years, reports on extinction and biodiversity loss have pointed toward a global

drop in species.

Back in 2019, hundreds of researchers from a UN-backed international organization found

that one million species of fauna and flora are at risk of extinction.

Experts estimate that today’s extinction rate is between 1,000 and 10,000 times higher

than the background rate.

Measuring biodiversity losses is incredibly complicated, especially because there’s

no standard way to do it.

-There isn't like a one size fits all metric that we could use that we can always know

that will always be appropriate.

-The most common way to track biodiversity is to measure species richness, or count the

number of species in a particular place and time.

Another metric is species evenness, which tracks the population levels of different

species, just to name a few.

-It's a good idea to actually look at multiple metrics...because these metrics

of biodiversity are not fully independent.

-And they also only capture certain facets of biodiversity.

Depending on what metric you use, you could get completely different results.

When it comes to conservation efforts or biodiversity offsets, like when developers measure biodiversity

loss for a project,how we measure biodiversity can really make a difference.

On top of that, global averages don’t always reflect biodiversity variation on a local

scale.

It's important to look locally since biodiversity affects how ecosystems impact water supply,

fuel, pollination, food, and more for their surrounding regions.

And what researchers are finding is pretty surprising.

Turns out, local biodiversity measures are incredibly mixed and some ecosystems are doing

even better than we might expect.

-Instead of seeing biodiversity loss everywhere, we saw a bit of a balance of losses and gains.

-But don’t get TOO excited yet.

-What we also see pretty much everywhere, is a shuffling of species.

By shuffling, we mean that some species are dying out or leaving ecosystems, while others

are entering them, changing the composition.

-We think that this shuffling of species is partly responsible for this disconnection

of how biodiversity is changing at different scales.

-Researchers from the University of Hawai’i simulated local coral reefs over two years

and found that species shuffled but did not collapse despite warmer temperatures and ocean

acidification.

That’s great news right?

Well, maybe…what that means for the health of the reef is not entirely clear yet.

Species shuffling can happen in a number of ways.

One study found that over the past 29 years, fish assemblages in the North Atlantic were

becoming more similar to each other—a.k.a homogenized.

Over time, southern species moved north to warming waters caused by the climate crisis.

In some cases these new arrivals are generalist species, which thanks to their ability to

thrive in various environments, can increase competition for resources.

For example, cane toads are one of the world’s most widespread invasive species.

In Australia, their introduction led to the rapid population decline of native endangered

species like northern quolls.

To get a clearer picture of what’s going on, we need data, a lot of it.

Most of the current research is concentrated in Europe and North America.

We’re also sorely lacking information from the tropics, where half of the Earth’s known

species reside.

Luckily, there are several efforts working to fill in those gaps.

Maria is part of BioTime, an open access database of studies in the same ecosystems over a number

of years.

The database now has 12 million entries for about 50,000 species.

Another notable project is EuropaBON, which hopes to use sensors, drones,

and citizen scientists to create a more complete picture of Europe’s species makeup in the

coming years.

All this data could have a huge impact on policies and goals to conserve as much biodiversity

as possible.

Many studies show that we’re still on track to lose almost half the world’s known species

by 2100, so if we want to course correct, we’re going to need all the help we can

get!

One of the coolest things about biodiversity research is that a lot of it is done by regular

citizens surveying their local habitats.

And this is where we come in: -I would strongly encourage people to engage

with these kinds of efforts because not only are they helping science.

They might be surprised by all the diversity that's at their doorstep.

-If you want to learn more about conservation efforts going on right now, check out our

series Rewild.

So what else do you want to know about the 6th mass extinction?

Let us know down in the comments, don’t forget to subscribe, and I’ll see you next

time on Seeker.