Spineless creatures that rule the world

31 August 2012 | Media advisory

One-fifth of the world’s invertebrates may be threatened with extinction according to ‘Spineless,’ a report published today by the Zoological Society of London (ZSL), in conjunction with IUCN (International Union for Conservation of Nature) and the IUCN Species Survival Commission.  

Digging up earthworms, chasing butterflies and collecting clam shells could become a thing of the past if enough isn’t done to protect invertebrates. And if they disappear, humans could soon follow. These critters form the basis of many of the essential benefits that nature provides: earthworms recycle waste nutrients, coral reefs support a myriad of life forms and bees help pollinate crops.

“The IUCN Species Survival Commission is currently trying to expand the number of invertebrates species assessed for The IUCN Red List of Threatened Species™,” says Dr Simon Stuart, Chair, IUCN Species Survival Commission. “The early results of this work are included in the Spineless book. I very much hope that the expansion of conservation-related information on invertebrates will give these species a much higher conservation profile in future.”

More than 12,000 invertebrates from The IUCN Red List were reviewed by conservation scientists—who also discovered freshwater species to be under the highest risk of extinction, followed closely by terrestrial and marine invertebrates. The findings from this initial group of global, regional and national assessments provide important insight into the overall status of invertebrates. Together they indicate that the threat status of invertebrates is likely very similar to that of vertebrates and plants.

Invertebrates are at risk from a variety of threats and what starts off as a local decline could lead to a global extinction. Recognizing the growing pressures on invertebrates is critical to informing more effective conservation. Molluscs, such as the Thick Shelled River Mussels (Unio crassus), suffer from pollution from agricultural sources and dam construction, which affects the quality of the water they live in. Crayfish such as the Noble Crayfish (Astacus astacus), are at risk from the impact of invasive species and diseases.

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

The highest risk of extinction tends to be associated with species that are less mobile and are only found in small geographical areas. For example, vertebrate amphibians and invertebrate freshwater molluscs both face high levels of threat– around one-third of species are at risk. In contrast, invertebrate species which are more mobile, like dragonflies and butterflies, face a similar threat to that of birds, and around one-tenth of species are at risk.

“The ecology of vertebrates and the threats posed to them are reasonably well documented, and there is often more effort to conserve them—but the conservation attention paid to creepy crawlies lags far behind that of charismatic and well known animals like tigers, elephants and gorillas,” says Professor Jonathan Baillie, ZSL’s Director of Conservation. “We ignore the loss of invertebrates at our peril, as they provide many of the ecosystem services from which humans benefit.”

Invertebrates are the engineers of the many benefits which humans accumulate from an intact and fully functioning environment; however human demand for resources is continually increasing the pressure on invertebrate populations. This book paints a clear picture of how biodiversity is changing, and will enable experts to implement successful conservation plans for those invertebrates which are struggling to survive.

ZSL will be presenting ‘Spineless: Status and Trends of the World’s Invertebrates’ at the IUCN World Conservation Congress in Jeju on 7th September.