Vital invertebrates decline by 45 per cent, study finds

Decline in insect, worm and other populations will affect our health, water quality and food supply

Science Editor

A A A

Insects, worms and other small animals that carry out vital functions for life on earth have declined by 45 per cent on average over 35 years, threatening human health, water quality and food supplies, a study has found.

The rapid decline in the number of invertebrates – animals without backbones – is at least as bad as the well publicised plight of the larger animals, according to scientists who said they were shocked by the findings.

Although there has has been far less research on invertebrates than on vertebrates, what little has been done suggests that they are undergoing a catastrophic fall in abundance which is having a severe impact on “ecosystem services” such a pollination of crops, water treatment and waste recycling, the scientists said.

The International Union for the Conservation of Nature (IUCN) has assessed less than one per cent of the 1.4m named species of invertebrates, yet of those studied about 40 per cent are considered threatened. Invertebrates constitute 80 per cent of the world’s species yet one in five could be at risk of extinction, scientists found.

An in-depth study by the IUCN of 203 insect species found that the vast majority of them were declining. Other studies based on numbers of individuals found that invertebrates overall had declined by 45 per cent since the 1970s.

“We were shocked to find similar losses in invertebrates as with larger animals, as we previously thought invertebrates to be more resilient,” said Ben Collen of University College London, a co-author of the study published in Science.

Some 7,784 freshwater invertebrates are on the IUCN’s Red List Some 7,784 freshwater invertebrates are on the IUCN’s Red List (Rex Features)
“While we don’t fully understand what the long-term impacts of these declining numbers will be, currently we are in the potentially dangerous position of losing integral parts of ecosystems without knowing what roles they play within it,” Dr Collen said.

Long-term studies of the distribution of moths and four other big groups of insects in the UK, for instance, show that a substantial number of them have suffered a decline in their ranges over the past few decades.

“Globally, long-term monitoring data on a sample of 452 invertebrate species indicate that there has been an overall decline in abundance of individuals since 1970,” the scientists said.

Moths and butterflies, for which the best data is available, have declined in numbers globally by 35 per cent on average over 40 years. Other groups of insects have declined considerably more over similar periods, the scientists said.

Insects, spiders, crustaceans, snails and worms form part of an often hidden world of small creatures on which other plants and animals depend. They also carry out economically important services, such as pollination – 75 per cent of the world’s crops depend on insect pollinators, valued at 10 per cent of the world’s entire food supply, the scientists said.

Marine invertebrates make up over 95 per cent of all marine animal species Marine invertebrates make up over 95 per cent of all marine animal species (EPA_
Insects, along with vertebrate animals such as birds, are also important for waste recycling in nature, especially vital nutrients needed by plants. Invertebrates also play a critical role in the natural purification of contaminated water.

“Prevention of further declines will require us to better understand what species are winning and losing in the fight for survival and from studying the winners, apply what we learn to improve conservation projects,” Dr Collen said.

“We also need to develop predictive tools for modelling the impact of changes to the ecosystem so we can prioritise conservation efforts, working with governments globally to create supportive policy to reverse the worrying trends we are seeing,” he said.

Spineless and lifeless: The species in crisis

Freshwater invertebrates

Some 7,784 freshwater invertebrates are on the IUCN’s Red List, with 34 per cent of those considered threatened. Freshwater snails are the worst off, along with river mussels, freshwater crayfish, damselflies and dragonflies, which spend their early life underwater.

Marine invertebrates

These make up over 95 per cent of all marine animal species, from microscopic nematode worms to giant squid. Reef-building corals make the biggest living structures in the ocean, visible from space. The greatest concentration is found off Asia and South America.

Terrestrial invertebrates

More than 3,600 terrestrial invertebrates have been assessed by the IUCN and 42 per cent are threatened with extinction. Those under pressure include bees, moths and buttterflies. The iconic monarch butterfly of the western US has declined by 80 per cent since 1997.

PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Life and Style
Carol O'Brien, whose son Rob suffered many years of depression
healthOne mother's story of how London charity Maytree helped her son with his depression
Life and Style
food + drink
Arts and Entertainment
The cover of Dark Side of the Moon
musicCan 'The Endless River' carry on the tradition? See for yourself
News
Rob Merrick's Lobby Journalists were playing Ed Balls' Labour Party MPs. The match is an annual event which takes place ahead of the opening of the party conference
newsRob Merrick insistes 'Ed will be hurting much more than me'
Voices
A new app has been launched that enables people to have a cuddle from a stranger
voicesMaybe the new app will make it more normal to reach out to strangers
News
Liam Payne has attacked the media for reporting his tweet of support to Willie Robertson and the subsequent backlash from fans
peopleBut One Direction star insists he is not homophobic
Life and Style
healthFor Pure-O OCD sufferers this is a reality they live in
Life and Style
Sexual health charities have campaigned for the kits to be regulated
healthAmerican woman who did tells parents there is 'nothing to be afraid of'
Life and Style
fashion
Arts and Entertainment
The John Peel Lecture has previously been given by Pete Townshend of The Who, Billy Bragg and Charlotte Church
musicGodfather of punk will speak on 'free music in a capitalist society'
News
peopleAt least it's for a worthwhile cause
News
Shoppers in Covent Garden, London, celebrate after they were the first to buy the iPhone 6, released yesterday
tech
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Pharmaceutical Computer System Validation Specialist

£300 - £350 Per Day: Clearwater People Solutions Ltd: Pharmaceutical Computer ...

High Level Teaching Assistant (HTLA)

£70 - £90 per day: Randstad Education Birmingham: Higher Level Teaching Assist...

Teaching Assistant

£50 - £80 per day: Randstad Education Birmingham: Randstad Education is the UK...

Senior Java Developer - API's / Webservices - XML, XSLT

£400 - £450 Per Day: Clearwater People Solutions Ltd: Our client is currently ...

Day In a Page

A roller-coaster tale from the 'voice of a generation'

Not That Kind of Girl:

A roller-coaster tale from 'voice of a generation' Lena Dunham
London is not bedlam or a cradle of vice. In fact it, as much as anywhere, deserves independence

London is not bedlam or a cradle of vice

In fact it, as much as anywhere, deserves independence
Vivienne Westwood 'didn’t want' relationship with Malcolm McLaren

Vivienne Westwood 'didn’t want' relationship with McLaren

Designer 'felt pressured' into going out with Sex Pistols manager
Jourdan Dunn: Model mother

Model mother

Jordan Dunn became one of the best-paid models in the world
Apple still coolest brand – despite U2 PR disaster

Apple still the coolest brand

Despite PR disaster of free U2 album
Scottish referendum: The Yes vote was the love that dared speak its name, but it was not to be

Despite the result, this is the end of the status quo

Boyd Tonkin on the fall-out from the Scottish referendum
Manolo Blahnik: The high priest of heels talks flats, Englishness, and why he loves Mary Beard

Manolo Blahnik: Flats, Englishness, and Mary Beard

The shoe designer who has been dubbed 'the patron saint of the stiletto'
The Beatles biographer reveals exclusive original manuscripts of some of the best pop songs ever written

Scrambled eggs and LSD

Behind The Beatles' lyrics - thanks to Hunter Davis's original manuscript copies
'Normcore' fashion: Blending in is the new standing out in latest catwalk non-trend

'Normcore': Blending in is the new standing out

Just when fashion was in grave danger of running out of trends, it only went and invented the non-trend. Rebecca Gonsalves investigates
Dance’s new leading ladies fight back: How female vocalists are now writing their own hits

New leading ladies of dance fight back

How female vocalists are now writing their own hits
Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments