Our directory of things of interest

University Directory

Against the flow: halting invasive carp

The Chicago river is one of the region’s major sources of clean water, but it’s now threatened by Asian carp The Chicago river is one of the region’s major sources of clean water, but it’s now threatened by Asian carp Pigprox
06 May
2017
As one of America’s biggest cities, supplying clean drinking water to Chicago has been a top priority. But the grand infrastructure visions are providing opportunities for invasive Asian carp 

Residents of Chicago, Illinois, have the collective efforts of the Illinois-Michigan Canal, the Chicago Sanitary and Ship Canal, the Cal-Sag Canal, and the phenomenal effort of reversing the flow of the Chicago river in 1892, to thank for their regular supply of clean water. Since their construction over a century ago, these waterways have connected Lake Michigan and the Mississippi river network and ensured a regular flow of fresh water to keep the city well hydrated.

However, there have been some less predictable – and less desirable – consequences of this hydrological merging. Asian carp, also known as silver or flying carp, are threatened in their native habitat in the Chinese Heilongjiang, Yangtze, and Pearl River basins, but have become increasingly successful at populating the Mississippi river network since first being introduced into Arkansas catfish farms in the 1970s to control algae. Through latching onto the canals as a way of spreading their domain further across the country, there are now substantial fears that this invasive species may be able to access Lake Michigan and the wider Great Lakes – which store an incredible 21 per cent of the entire world’s fresh water.

‘The actual impact of Asian carp on the Great Lakes has yet to be defined clearly, and we think this uncertainty is part of the reason why they are such a prominent issue,’ says Dr Cory Suski, Associate Professor in the Department of Natural Resources and Environmental Sciences at the University of Illinois. He points out that adult Asian carp are too large to have any local predators, that they have a ‘prolific’ reproduction rate, and they can outcompete native species for food. ‘Could they survive in the Great Lakes or is there not enough food for them?’ he asks.

‘Would they move into and take over tributaries? No one is predicting positive benefits should Asian carp enter the Great Lakes, hence the impetus on keeping them contained.’

Halting the exploratory activities of the fish has therefore become a key concern for local lawmakers, who have undertaken efforts such as installing electric fences in the Chicago Sanitary and Ship Canal. However, any large-scale efforts to create obstacles for the carp – such as allowing the Chicago river to once again flow in its original direction – would in turn threaten the security of the city’s water supply, replacing one substantial problem with another.

This was published in the May 2017 edition of Geographical magazine.

Related items

Geographical Week

Get the best of Geographical delivered straight to your inbox every Friday.

Subscribe to Geographical!

Adventure Canada

EDUCATION PARTNERS

Aberystwyth University University of Greenwich The University of Winchester

TRAVEL PARTNERS

Ponant

Silversea

Travel the Unknown

DOSSIERS

Like longer reads? Try our in-depth dossiers that provide a comprehensive view of each topic

  • National Clean Air Day
    For National Clean Air Day, Geographical brings together stories about air pollution and the kind of solutions needed to tackle it ...
    The Air That We Breathe
    Cities the world over are struggling to improve air quality as scandals surrounding diesel car emissions come to light and the huge health costs of po...
    Hung out to dry
    Wetlands are vital storehouses of biodiversity and important bulwarks against the effects of climate change, while also providing livelihoods for mill...
    When the wind blows
    With 1,200 wind turbines due to be built in the UK this year, Mark Rowe explores the continuing controversy surrounding wind power and discusses the e...
    Mexico City: boom town
    Twenty years ago, Mexico City was considered the ultimate urban disaster. But, recent political and economic reforms have transformed it into a hub of...

MORE DOSSIERS

NEVER MISS A STORY - Follow Geographical on Social

Want to stay up to date with breaking Geographical stories? Join the thousands following us on Twitter, Facebook and Instagram and stay informed about the world.

More articles in PLACES...

Mountains

In this extract from his new book, Tides, mountain climber…

Cities

New data from the World Health Organization reveals that nine…

Water

In the wake of the water crisis in Flint, Michigan,…

Mapping

Benjamin Hennig maps out the global production and distribution levels…

Water

Millions of Americans are living in areas at high-risk of…

Mapping

New interactive maps combine precipitation and temperature to show climate…

Cities

Public transport in India could be on the verge of…

Water

To retrace the route of the fur voyageurs on the waterways…

Cities

IPCC Cities and Climate Change Conference: Alberta host dresses non-renewable…

Water

Increased carbon dioxide is affecting freshwater ecosystems

Forests

The latest laser scanning technology reveals new insights into the…

Forests

Deforestation is having an unexpected effect in the Amazon: fewer…

Forests

The iconic Douglas fir tree, familiar to fans of the…

Forests

Rocky Mountain forests are not regenerating after wildfires

Cities

Cape Town is edging closer to ‘Day Zero’, the long-feared…

Water

Ongoing restoration projects are breathing new life into Florida’s Everglades

Cities

Despite protests, an experimental pedestrianisation system is proving to be…

Mapping

National Archives map historian, Rose Mitchell, highlights some of the…

Water

An expedition into the Jordanian desert is helping teachers and…

Mountains

Trivia fans take note, Mount Hope in the British Antarctic…