Aug 31

A staggering one fifth of the world’s invertebrates could be at risk of extinction, according to a new report published today by the Zoological Society of London (ZSL), in conjunction with IUCN and the IUCN Species Survival Commission.

The culmination of a review of an incredible 12,000 invertebrate species on the IUCN Red List, ‘Spineless: Status and Trends of the World’s Invertebrates’ presents the findings of global, regional and national assessments, and paints a sombre picture of the current status of our planet’s spineless residents.

Long-horned beetle image

The long-horned beetle is classified as Vulnerable on the IUCN Red List

Essential invertebrates

While invertebrates are frequently met with disinterest, or even active dislike, they form the basis of many of the essential services that nature provides. From crop pollination by bees to water filtration by freshwater molluscs, humans rely on invertebrates for survival. However, with the ever-growing demand for resources, invertebrates are being placed under increasing pressure.

Invertebrates constitute almost 80 percent of the world’s species, and a staggering one in five species could be at risk of extinction. While the cost of saving them will be expensive, the cost of ignorance to their plight appears to be even greater,” said Dr Ben Collen, head of the Indicators and Assessments Unit at ZSL.

Elegance coral image

Many corals, such as the elegance coral, are under threat

Status and Trends

The recent report set out to evaluate what is known about the status and trends of marine, freshwater and terrestrial invertebrate populations, and to assess the importance of these species to human beings. This latest research has led scientists to the worrying discovery that invertebrates are just as threatened as vertebrates and plants, with freshwater species faring least well.

Professor Jonathan Baillie, ZSL’s Director of Conservation, explained, “We knew that roughly one fifth of vertebrates and plants were threatened with extinction, but it was not clear if this was representative of the small spineless creatures that make up the majority of life on the planet. The initial findings in this report indicate that 20 percent of all species may be threatened.  This is particularly concerning as we are dependent on these spineless creatures for our very survival.”


Noble crayfish image

Invasive species and diseases are placing extreme pressure on invertebrates such as the noble crayfish


Invertebrates are facing a variety of threats, with species such as the noble crayfish being placed under extreme pressure from the impacts of disease and invasive species. Freshwater invertebrates in particular are at risk from pollution from dam construction and agricultural sources, which affects the water quality of their natural habitat.

The report indicates that the highest risk of extinction tends to be associated with those species that are less mobile and that are only found in a small area, as their ability to disperse to regions of more suitable habitat is extremely limited. For example, one tenth of more mobile species such as dragonflies and butterflies are at risk, whereas a staggering one third of freshwater mollusc species are considered to be threatened.

By understanding the threats to invertebrates, and recognising the growing pressures being placed on them, it is hoped that positive action can be taken.

I very much hope that the expansion of conservation-related information on invertebrates will give invertebrates a much higher conservation profile in future,” said Dr Simon Stuart, Chair of the IUCN Species Survival Commission.

Swallowtail butterfly image

Swallowtail butterfly

Looking to the future

The report paints a clear picture of how invertebrate biodiversity is faring, and it is hoped that the findings will enable conservationists and other experts to develop and implement effective conservation plans for the many invertebrate species which are currently struggling to survive.

We need to successfully communicate the significance and value of invertebrate life, if we are to rescue the many thousands of threatened species from the brink of extinction,” said Richard Edwards, Chief Executive of Wildscreen. “This important report highlights the impact we are having on the world’s invertebrate biodiversity, species we all rely on for healthy natural systems, sustainable livelihoods and human well-being.”


Read the full report on ZSL’s website.

Explore invertebrate species on ARKive.


Kathryn Pintus, ARKive Species Text Author