These "Living Planet Index" population figures are potentially confusing if you don't know how to read them and they have lead to many mistaken media stories.It does not mean that there are 88% less total numbers of large animals in our rivers and streams. We do not risk a world without salmon, hippos, beavers or crocodiles. Many outlets also ran it as a story about a greatly increased extinction risk for these animals. They did not even assess extinction risks and nothing in this report overrides the work of the IUCN red list.

This paper is using the “Living Planet Index” which is designed to emphasize the changes in small populations. It is also patchy, which is not their fault. They relied mainly on data submitted to the Living Planet Index database, and this is limited for freshwater megafauna. Though they supplemented it with other studies, they still had almost no data from South America, Africa, the Mediterranean, or the Middle East, and 28% of their time series are for just three species, the Chinook salmon, the Atlantic salmon and the brown trout, all migratory species severely impacted by hydro dam projects.

This example from the National Geographic explains how the living planet index works:

Suppose you had

  • 50 tigers decline to 5 (by 90%)
  • 200 falcons decline to 40 (by 80%)
  • 10,000 squirrels decline to 9,000 (by 10%)

Then you’d work out their Living Planet Index as:

(90 + 80 + 10)/300 = 60

So you would say that overall, the populations have declined by 60%. But the total population of squirrels is hardly affected at all.

It is the same within species. Suppose for instance we are looking at polar bears and:

  • One group has 50 individuals and declines to 5,
  • another has 200 and declines to 40
  • another is a huge population of polar bears, 10,000 and it declines to 9000.

Again you’d say the polar bears have declined by 60%. But the total population has actually declined by only 12%.

You could even have a total population increase and yet report a decline.

  • One group has 50 individuals and declines to 5,
  • another has 200 and declines to 20
  • another is a huge population of polar bears, 10,000 and it increases to 11,000.

It would still be reported as a 60% fall although the number of individuals has actually increased this time, from 10,250 to 11,025

So this way of measuring populations has had some criticism in the past. But it is perfectly okay scientifically so long as you understand what it is doing.

It is strongly biased towards showing you the effects of fluctuations in small populations of individuals over large ones and that is important to know, if the range of a population is decreasing.

As the National Geographic put it, talking about an earlier similar study from 2018, also using the Living Planet Index:

“since each distinct population makes the species more resilient, it’s still important information for biologists to capture.”

Widely misinterpreted report still shows catastrophic animal decline

The extra populations make it more resilient to local events (volcanic eruptions, wild fires etc) and also can be pockets of genetic diversity giving more resilience to the genome. To take an example, perhaps one of the small populations is adapted in ways the big population is not (e.g. to warmer conditions, or drier conditions, say). Also their genes might be useful to help avoid inbreeding, and they may be signfiicant locally, either culturally or commercially (the near extinct Yangtse soft shelled river turtle for instance is of great cultural significance in China, although there are many other species of large soft shelled river turtles worldwide).

They use an updated more complex calculation for the Living Planet Index which is diversity weighted, gives more emphasis to the under represented groups, to help compensate for the tendency for the index to have many more time series for some groups of species than others:

So with this background this is another “Living planet index” article that is getting alarming headlines.

These are the headlines I mentioned that give the mistaken impression that they were saying that we soon will have a world without beavers, hippos, crocodiles or river turtles. No, it doesn't mean that at all. It's not even what it is about.

Though it has some remarks about extinction risks, and the need for improved monitoring to assess them better, it is not itself an extinction risk assessment. For that go to the IUCN Red List, e.g. here is a red list search for Salmon and for Hippo.

This is another article I'm writing to support people we help in the Facebook Doomsday Debunked group, that find us because they get scared, sometimes to the point of feeling suicidal, by such stories.

Do share this with your friends if you find it useful, as they may be panicking too. If you are in the middle of a panic attack right now, see my

WHAT TO DO IF YOU SEE A SCARY STORY LIKE THIS AND GET A PANIC ATTACK

If you see a story like this in the news, and start panicking, here are some things to do.

  • This is not urgent - it doesn't have to be solved in this minute or hour. If you think it is try the slow breathing for ten or twenty minutes or however long it takes to get over your panic attack. This is a natural physiological response. If you breathe slowly, it calms your mind. You don't need to do anything with your mind, it's not meditation, just slow breathing. It may help to use animated gifs to pace yourself, see my page here:
    Breathe in and out slowly and deeply to calm a panic attack

    There are other things you can do to, mindfulness, chair yoga, various tips on that page and links to the UK Mind site and the Destress Monday site.
  • Almost any story like this is bound to have a lot of journalistic exaggeration - and whatever it seems to say, it doesn't mean a world without nature.

    Yes our generation’s children are headed for a world with nature and wonder in it - and their children too
  • When you panic, whatever you are scared of seems of overwhelming importance but remember previous panics (if you have had them), they also seemed so at the time. But later you normally find they are not and then all that panicking wasn't even needed.
     
  • Even if there was something concerning, it's about something that unfolds over decades and we have decades to find a way to find a solution. You may help solve it yourself, through life choices, direct action, how you vote - but it is not something has to be solved urgently as in right now, today, this hour,

You can do that with any of these scary stories. Anything else you may need to do in your life, any commitments you have to others, things you keep putting off you need to do, are far more important right now than these stories.

I so often hear from people who put off important things to spend hours on the internet getting themselves more and more scared by reading stories like this.

See also my

SO WHAT DOES IT MEAN?

A bit of grounding and common sense may help here. Many of these are animals of least concern. Look up, say, the Hippo (one of their species they studied) in the IUCN red list. Although it is listed as “Vulnerable”, the population is stable and they say there are 115,000 to 130,000 common hippos extant today. No way are they talking about the near term extinction of Hippos.

Hippotamus - the IUCN Red List of Threatened Species (for other species of Hippo see Hippo)

Or the Atlantic salmon, one of the species they have most data about in their time series, it’s of least concern. Though locally there may be problems with salmon in some rivers, there is no way that this means that globally we are looking at a possible world without salmon.

Salmon - the IUCN Red List of Threatened Species

There was an earlier report in 2018 which came to the conclusion that freshwater animals populations are declining much more than terrestrial or sea water populations, again using this Living Planet Index which emphasizes changes in small populations over large ones.

Freshwater wildlife face an uncertain future

At the end, the paper itself says that though there are many declining populations (according to this “Living Planet Index” way of measuring them), there are also many conservation successes.

They mention as an example that 13 American species are now stable or increasing due to conservation efforts (e.g., the green sturgeon, Acipenser medirostris; white sturgeon, Acipenser transmontanus; and American beaver, Castor canadensis)

I am discussing this paper:

The abstract says that globally freshwater megafauna declined by 88%.

By megafauna here, it means a creature (fish, amphibian, reptile, or mammal such as a hippo) that has an adult weight above 30 kg.

The paper focuses on the declines, but it had increases as well. Overall the mammal populations they looked at increased.

Here is their graph for mammals:

There the white line shows this averaging process I just described and the blue shows the range of all the different data sets they had, which are evaluated to give a confidence interval for the result.

Mammals according to this rather unusual type of averaging process have increased by 50%. This means that they are doing well overall, even small populations tend to increase rather than decrease, not just the big ones. Some again are likely increasing as much as three and a half times the original population.

This doesn’t mean they are all doing fine. Take the river dolphins for example. One species of river dolphin has gone extinct, and several are struggling but one is actually recovering. More on that later.

Reptiles aren’t doing so well

However it is fluctuating a lot, there was a big dip up in 2010 then a dive down. Notice that the uncertainty is very high though.

The news stories highlight the Yangtse soft shelled river turtle which is probably functionally extinct - only three left, two in the wild in Vietnam and one in captivity in China. But - it is only one of 18 species of soft shelled river turtles in the IUCN red list and although most are at some level of "threatened" in the IUCN classification scheme, there are a couple of species of least concern.

More on that later, I’ll look at those two examples of the soft shelled river turtle and river dolphin in detail at the end.

Also not all the regions showed declines. This is for Australia. The white line is more or less level and is that average biased towards small populations that I described, the Living Planet Index. This means even small fragmented populations are doing okay there.

The range is huge, so there is a lot of “uncertainty” due to some time series doing very well and others not so well but you can also see that some are likely increasing nearly 4-fold.

LIMITED COVERAGE AND PATCHY DATA

But before we get too carried away it’s worth looking at another figure, from their supplementary data. This shows how much coverage they had

Gray there means no data and light blue is only 1 - 5 time series, and next sep up is 6 - 15.

Many countries in Africa, around the Mediterranean, and in the Middle East have no data at all.

This does not mean that nobody has done any observations of numbers of freshwater fish in Spain or Italy say over the time period of interest (from 1970 to the present). It may just be that this data has not been submitted to the Living Planet Index. That is their main source of information, although they did supplement it with some other papers.

The Living Planet Index is a collaborative project that relies on researchers to contribute data to it.

It is well possible that there are many data sets worldwide that have not been uploaded to it.

Also their is more patchy even than that map suggests. That doesn’t mean 6 - 15 species. Many of the time series are for a single species e.g. in Africa there are 15 time series for the Hippo.

LEAVES OUT INVASIVE SPECIES

Another limitation is that they have intentionally not counted many invasive species outside their original range (naturally enough, especially as there would often be control programs for them).

They give the example of the wels Catfish an invasive fish in many European catchments. If this has edged out some other freshwater fish it will be registered as a decline of freshwater fish in Europe, even if the number of fish is the same, but with more catfish and less of the other fish.

So, when they talk about the ranges are all decreasing - well by leaving out invasive species they are excluding many of the ones whose range is increasing.

So, this is not in any way a systematic survey of freshwater creatures even using the Living Planet Index. It is just a first dip of a toe into the water.

THEIR CENTRAL MESSAGE - NEED FOR MORE MONITORING

Their strongest message is that we need more monitoring. They do not claim that this is a systematic survey and they mention some of its limitations in the discussion section.

Also - note that they did not do any research themselves, it’s a review, a non systematic preliminary high level review.

There are likely to be many individual databases and records of observations worldwide that have not been submitted to the Living Planet Index. There are probably many also that exist as field observations in various places that have not yet been analysed and written up in scientific papers. Also, there are surely many scientific papers that they have not covered as they did not attempt a systematic review of the scientific literature.

STRONGLY WEIGHTED TOWARDS INDIVIDUAL SPECIES, E.G. SALMON

But it’s even more patchy than that. The data they found is strongly biased towards particular individual species. Looking at the supplementary data, out of their total of 636 time series then the time series numbered 96 through to 277 cover only three species, the Chinook salmon, Atlantic Salmon and Brown Trout for a total of 182 time series. Those three species alone constitute over 28% of the data. These are migratory fish that can be severely impacted by hydro projects - even with careful design work on the dams, there is more to it than fish ladders (more on this later).

Add in the other salmonids and the sturgeon and that’s 60% of the data they have for fish although these species are only 18% of the population of fish species.

It is diversity weighted which will help prevent this overwhelming the graph, but there’s a limit to what you can do if other species are just not in the data.

107 of the time series were from Norway, or about 17% of the data. Another 153 were from the US + Canada combined or another 24% of the data making more than a third of the data from just those three countries, mainly because they have a lot of data on salmonids.

So, the data is strongly weighted towards particular species and particular countries, but they did manage a reasonable coverage of the rest, over half of all except the reptiles, but many of the species had only a few time series and they looked mainly at data for those regions coloured darker blue on the map.

Their species coverage was

  • 81 fish (62% of the total),
  • 22 mammals (73%)
  • 21 reptiles (48%)
  • and 2 amphibians (the Chinese giant salamander, Andrias davidianus; and Japanese giant salamander).

They remark on these limitations in the Discussion section. They do not claim that the study is more than it is, but the media are making it out to be more systematic than it is, as well as not understanding what the “Living Planet Index” really means.

So, as they remark in the discussion, they have very little information about Africa. They have most information of all about the US and Canada, and Norway. Also reasonable data for Australia, China and India. Other places there isn’t that much.

There are other issues as well, as we can see from looking at the example of Australia?

EXAMPLE OF AUSTRALIA

For Australia, what is behind the big recovery they show there for some time series (nearly four fold)?

Well, there are 12 time series for the saltwater crocodile all from a single paper about the recovery of saltwater crocodiles in the Northern Territory of Australia after they stopped hunting them in 1971. So it is no wonder that the upper part of their Australian time series is strongly increasing. Remember that these are 12 of the data points for Australia.

Saltwater crocodiles (Crocodylus porosus) in the Northern Territory of Australia were protected in 1971, after a severe population decline resulting from 26 yr of intense commercial hunting. By that time wild saltwater crocodiles were rarely sighted anywhere and they were commercially extinct in areas where they had once been abundant. Standardized monitoring by spotlight surveys started in 1975 and provided relative density indices over time (1975–2009) as a unique record of the post-protection recovery of a wild crocodilian population.

“Recovery of saltwater crocodiles following unregulated hunting in tidal rivers of the Northern Territory, Australia.”

Another four time series are for a paper

It reports a 77% decline in total freshwater crocodile numbers after the cane toad invasion. But the IUCN red list has a comment saying that this decline is only in the younger crocodiles and has made no difference to the number of adults. It’s common for many young in a species to die anyway in the first few years. Because of the cane toads this has changed to a population with a smaller number of young, but the same number of adults as before.

“Despite multiple reports of no detriment to mature C. johnstoni (>1.5 m) from cane toad ingestion, and thus to the effective population size, continued monitoring should be continued to ensure there is no effect on future recruitment given the large decreases in the intermediate age classes. Population surveys of C. johnstoni populations, where Cane Toads have been in existence for some time, such as in Queensland, may provide important information regarding the long-term effects on the species from Cane Toads.”

Australian Freshwater Crocodile - The IUCN Red List of Threatened Species

So, population declines don’t always capture the whole story. In this case though there was a 73% decline in the population as a whole, most likely the number of adults is unchanged though this is being monitored.

Incidentally cane toads naturally collapse after an invasion. In this study they found a 98% collapse 27 months after their invasion into their study site in tropical Australia. And

Then they have ten time series for Crocodylus porosus from ten different estuaries in Northern Australia where it has had total protection since 1972, the surprise here is that it hasn’t recovered as much as they expected:

Population Dynamics and Status of Crocodylus porosus in the Tidal Waterways of Northern Australia."

They have one for the Common carp which is actually a paper about a program to control this invasive species so of course would show a decline, maybe this was included accidentally?

And one time series for the Barramundi

Total of 28.

COMBINED PICTURE

Because of the way they combine the data together, even though mammals are doing fine on average and reptiles are doing not too badly too, they get a rapid decline like this for the overall picture once they add in the mega-fish, especially since so many of the time series were for the salmonids and other megafish. This is the result, the graph taken from the article about this research in Nature:

And for fishes

Giant freshwater fishes are in alarming decline (Nature)

But remember you can get a decline like this due to small populations declining even if there is a big population that is level or even increasing.

It does not mean our rivers are rapidly emptying of megafauna.

But it does mean that many small populations are disappearing of some species, the ones they focused on.

A lot of this is invisible because it is beneath the water and they are saying that we need a similar conservation movement for the megafauna in freshwater that we have for land and sea animals and that is the main thing,

ISSUES OF DAMS FOR MIGRATORY FISH LIKE SALMON

They talk about many issues that face the megafauna and that includes dam construction.

Most dams are now built with fish ladders and most salmon are able to swim up them.

Click to watch on YouTube

However, that’s not the only problem they face. A bigger problem is for the smolts, the young ones. They need to get down to the sea within 15 days after hatching or they will lose their downstream swimming behaviour and also lose their ability to switch to the salt water environment. Patrick McCully reported back in 2001:

During years of relatively low flow, smolts from the upper Snake River, the Columbia's main tributary, can now take up to 39 days to swim to the sea, compared with less than three days before the dams were built.

Dams and Migratory Fish

They also have to swim through the reservoirs where birds and predatory fish wait for the feeding bonanza.

This is one of the main reasons for the decline of salmon in many of our rivers:

The pattern of destruction on the Columbia and the other rivers of the US Pacific seaboard has been repeated elsewhere. The Atlantic salmon population in the United States declined from half a million in the early 18th century to a few thousand, mainly hatchery-reared, fish in the 1990s. By the end of the 19th century, dams had eliminated Atlantic salmon from France's Dordogne, Meuse and Moselle. During the 20th century salmon have disappeared from the Garonne and the Seine. The Loire and its tributary the Allier are now the only long French rivers which can sustain wild salmon.

Dams and Migratory Fish from Silenced Rivers: The Ecology and Politics of Large Dams by Patrick McCully, 2001.

By now 18 years after he wrote that, they are no longer found in the upper Columbo river.

It’s not a surprise that a study that has so many time series for salmon would find a sharp decline.

It is the same reason for declines in sturgeon, lamprey eels, and many other species:

The hilsa, a migratory fish of great commercial importance in South Asia, was deprived of 60 per cent of its previous spawning areas on the Indus by Pakistan's Gulam Mohammed Dam; while the Stanley Dam wiped out the hilsa from the Cauvery River in south India.

They also have serious effects on giant freshwater prawns and river dolphins.

They highlight dams as one of the main things we need to pay attention to in the future in the paper:

For example, approximately 3,700 additional large hydropower dams are planned or under construction, increasing the fragmentation of rivers worldwide

SEARCHING FOR SOLUTIONS - EXAMPLE OF THE SALMON CANON

But there can be solutions. Here is one of them, the “salmon canon”

Click to watch on YouTube

Going For Launch With The Salmon Cannon

That’s for hatchery fish, but it may also be useful for helping the young to get down to the sea faster.

Whooshh: No dam problem with the salmon cannon

Tribes Release 1st Salmon Into Upper Columbia Since Dam Construction

Since many of the fish impacted are these migratory salmon etc, it could be that if the dams were better designed maybe with the salmon cannon or something else someone thinks of, they can recover back to their former levels.

LONG LIVES CAN CONCEAL PROBLEMS IF THERE ARE FEW YOUNG

In the paper they talk about how the megafauna in rivers have long lives, and they may seem to be fine, because you see adults years and decades after they are functionally extinct. There are no more young ones but there are plenty of adults for a while so you do not notice what is happening. So, they say, we need a lot more careful monitoring. They see these graphs as being signs that there may be populations there that may not be doing as well as they seem to be, if we look at them more closely.

So their big message is about the need for more monitoring of freshwater megafauna and to draw them to the attention of the public.

There is still a window of ooportunity here. If this monitoring finds a population at risk there are decades of opportunity even if a population is functionally extinct, to find a way around the problem before all the adults have died.

In the paper they also warn about the risk of diverting money away for megafauna that may be needed in a more integrated approach - ie. expensive projects to save just a few species.

So with limited funding it's important to be wise about how you use it. Not just to save particular megafauna but to keep in mind the overall picture as well. They talk about using the freshwater megafauna to get people interested in conserving freshwater species generally.

Of course there are some critically endangered fresh water fish and mammals just as there are for land animals and sea animals.

EXAMPLES FROM THE NEWS STORIES ABOUT THIS STUDY - YANGTZE SOFTSHELL TURTLE

The news stories focused on a few examples and these help illustrate the problems. There are only three left of the Yangtze giant softshell turtle

It is a freshwater turtle and the largest in the world. There are a couple of wild ones left in Vietnam and one in captivity, and they are all male after the only female died.

This was their attempt to save the species.

Click to watch on YouTube

But sadly she died without laying any eggs.

Click to watch on YouTube

One of the world's rarest turtles dies

They have cryopreserved the ovarian tissue which is the main source of female gametes. They are not the same as eggs but have the potential to develop into the mature fertilizable oocytes.

Cryopreservation of ovarian tissue: an emerging technology for female germline preservation of endangered species and breeds.

There are two left in Vietnam of unknown gender.

It is functionally extinct unless a female is found. But there are many species of soft shelled turtles. It is not the last soft shell turtle in the world.

Here is another species of soft shell turtle though that is being saved from extinction in Cambodia.

Click to watch on YouTube

So, the three left is just for one particular species, the Chinese Yangtze giant softshell turtle

The IUCN red list gives 18 species of soft shell turtle, and two are of least concern, two critically endangered (including the Yangtse one), one is extinct in the wild, and the others are a mixture of vulnerable and endangered.

The IUCN Red List of Threatened Species - softshell turtle search

There those different categories are to do with it’s population size, whether it is increasing or decreasing etc. And this does not take account of any future conservation efforts, often creatures are moved e.g. from critical to endangered, endangered to vulnerable etc.

  • Critically endangered - 50% chance of extinction in the wild within 10 years or three generations , or less than 50 mature individuals.
  • Endangered - 20% chance of extinction in the wild within 20 years, or five generations, or less than 250 mature individuals
  • Vulnerable - 10% chance of extinction in 100 years, or population size less than 1000 mature individuals.
  • Near threatened - not in any of those but close to qualifying, or likely to in the near future.
  • Least concern - doesn’t qualify for any of them.

Here, when it says e.g. “within 10 years or three generations” that means, whichever is longer, ten years or three generations, where for long lived creatures (e.g. Greenland sharks with a lifespan of 500 years or so) then it’s up to 100 years instead of the number of generations given.

So, they don’t actually have to have any assessed percentage risk of extinction to count as threatened. A population of 1000 mature individuals in a stable population would count as vulnerable, because there are so few of them. There are other ways they can be threatened including being in a fragmented or geographically small area. Details here.

Here for instance are their assessments for various species of:

See also this section of my online article on the IPBES report:

EXAMPLE OF THE CHINESE BAJU RIVER DOLPHIN

For another example, there are four families of river dolphins and one of them has gone extinct with the last remaining species in that family now gone, the Chinese Baju river dolphin.

This is at least partly because of the Three Gorges Dam

The Three Gorges Dam could deal the final blow to the Yangtze river dolphin, the baiji, one of the world's most endangered species, with only 150 to 300 animals left

Dams and Migratory Fish

from Silenced Rivers: The Ecology and Politics of Large Dams by Patrick McCully, 2001.

Eighteen years later it is indeed extinct, or thought to be.

Baiji - Wikipedia

But as with the softshell river turtle it is not the end of the river dolphin generally, but it is for that particular species and family too (as it was the sole surviving species of its family).

WWF lists seven river dolphin species around the world that it is helping to conserve

IUCN lists nine species of river dolphin. Most decreasing, some unknown, ranging from critical all the way to near threatened (between vulnerable and of least concern)

The IUCN Red List of Threatened Species

So, it's not saying that your rivers won't have any fish in them any more, or that we are looking at a future world without freshwater fish. And the vulnerable species are not ones that are extinct, they can be saved.

And many of the declines are due to dams, so this is something we can work on. Maybe innovative projects like the salmon cannon can help migratory animals and ones that need a large range.

Their main conclusion is that there are large gaps in our understanding of freshwater megafauna and that we need to fill those as part of proactive conservation strategies, especially in the megafauna rich basins such as the Amazon, Congo, Mekong and Ganges river basins.

There remain large gaps in freshwater megafauna monitoring and assessment, which is the first challenge that must be tackled. To aid the establishment of proactive conservation strategies, future studies focusing on population monitoring, distributions (e.g., key habitats, migratory routes), and life‐history traits of freshwater megafauna are called for. These are particularly necessary in megafauna‐rich basins (e.g., the Amazon, Congo, Mekong, and Ganges river basins) and must account for rapidly increasing and emerging threats.

In addition, a comprehensive and regularly updated database of freshwater megafauna species is sorely needed, alongside a global initiative to combine and consolidate knowledge and data on freshwater biodiversity

SEVEN TIPS FOR DEALING WITH DOOMSDAY FEARS

If you are scared: Seven tips for dealing with doomsday fears which also talks about health professionals and how they can help.

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