Report warns migratory fish, mammals and birds at risk of extinction

Risks to migrating mammals, birds and fishes are rising, a landmark report has warned.

The first State of the World's Migratory Species report found that countries aren't doing enough to save threatened species, which are in danger of falling through gaps in legal protections.

Even though they're meant to be protected, sharks, rays and sturgeon are in danger of disappearing.

The State of the World's Migratory Species report reveals that 97% of fishes listed under the Convention on Migratory Species (CMS) are threatened with extinction. Our voracious appetite is pushing many species towards the brink, with pollution and bycatch also driving the dramatic declines.

Dr. Rupert Collins, the Natural History Museum's Senior Curator of Fishes, says, "Migratory fishes are affected by almost every negative impact that humans have on the planet, not just overfishing."

"The destruction of habitats like mangroves removes important shelter for young fish to grow up in, dams obstruct their passage, while plastic and sewage pollution swamp their environment.

"Unfortunately, they don't currently have much of a chance where humans live, and that's the sobering reality of the report."

As well as fish, hundreds of other mammals and birds are also at risk. While 14 species are now in a better position than they were in the 1970s, such as the humpback whale, these successes are outweighed by the 70 animals which are now more endangered than ever.

Inger Andersen, Executive Director of the United Nations Environment Program, says, "Migratory species act not only as indicators of environmental change but play an integral role in maintaining the function and resilience of our planet's complex ecosystems."

"Today's report clearly shows us that unsustainable human activities are jeopardizing the future of these creatures. The global community has an opportunity to translate this latest science of the pressures facing migratory species into concrete conservation action."

The report was launched on the first day of CMS COP14, an international meeting that hopes to provide additional protections for migratory species.

Why are fishes under threat?

Many animals live their life on the move, walking, swimming or flying across the world as part of regular migrations as they travel seasonally to breed and feed.

As they move around, migratory species can help to spread seeds, cycle nutrients, and sequester carbon dioxide. They're also a vital part of food webs, feeding on and being fed on by many other species.

By their very nature, these animals end up crossing borders, which can cause problems. What may be considered a protected species in one country might not be in another, meaning animal may never reach their intended destination.

To try and address this, in 1979 many of the world's nations signed up to the CMS pledging to conserve the species listed. Today, over 130 states have signed the convention, although there are some notable absences such as the U.S., Japan and China.

Under the convention migratory species considered at risk are put into one of two categories. Appendix I is for species threatened with extinction, and Appendix II for those with an "unfavorable" conservation status.

The new report reveals that many species on both lists are in decline. Over three-quarters of Appendix I species are in decline, while the populations of 42% of species in Appendix II are falling.

Of the species listed, fishes are the most threatened. Species like giant manta rays, whale sharks and the European eel have seen an average population decline of 90% since 1970. In part, this is likely because the large ranges of these species make their habitat difficult to protect.

"Fish that are born and die in the same place are easier to conserve, as protected areas can cover their entire range," Rupert says. "Migratory fishes are much more susceptible to our impacts, as it's not easy to create protected areas that link all the different habitats they might use over their lifetime."

But of all the fish, sturgeons are the most threatened. The popularity of their meat and caviar, as well as pollution and water abstraction, has led to these animals becoming highly endangered, with some species already thought to have become extinct.

How are migratory animals doing?

The problems being faced by sturgeons are representative of wider issues for migratory species. Both habitat loss and overexploitation affect more than 70% of these animals, with pollution having the third greatest impact.

Together, these factors are estimated to have caused a 15% decline in migratory populations between 1970 and 2017.

The greatest declines are happening in biodiverse continents such as Asia and Africa, while Europe is showing slight improvement (although this may be because much of its biodiversity has already been lost).

While mammals, birds and reptiles appear to be bucking the overall trend, it may be related to a few species recovering strongly which is offsetting the losses from many others. In addition, the population trends of around a tenth of species are also unknown, making it hard to work out how they are faring.

Turning around historic declines will not be easy, but many of the actions are relatively straightforward. The report calls for the existing network of protected areas to be expanded and more effectively protected, noting that over half of sites important for migratory species are under unsustainable pressure from humans.

It also calls for better protections against illegal killings of migratory animals. For example, around the Mediterranean, it's estimated that around 25 million birds die every year from illegal hunting despite international agreements.

A more difficult task, however, is to assess the conservation status of many oceanic migratory species. The difficulty of assessing marine creatures like fish, squid and crustaceans means that, in many cases it's simply not known how well their populations are doing.

"We don't necessarily know the extent of the natural ranges for many species, how they use their habitats, and to what degree they migrate," Rupert adds. "It's a particular problem in the tropics, where there are thousands of species which are yet to be described or even studied at the most basic level."

In the meantime, the report lists 399 species that might benefit from being listed in the CMS, including the emperor penguin, the walrus, and two species of horseshoe crab.

These potential new listings will be among the topics delegates to CMS COP14 will be discussing, as they hope to close a new deal before the conference ends on 17 February.

This story is republished courtesy of Natural History Museum. Read the original story here.