Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

If we are what we eat, some lake fish are made of maple leaves

15.01.2004


Study shown fallen leaves play a role in the food web



Aquatic plants form the base of the food web. The energy they create supports aquatic life, from invertebrates to the largest sport fish. Now, a study shows that aquatic plants are receiving a little help from trees. In a paper in this week’s issue of the journal Nature, Michael Pace and Jonathan Cole of the Institute of Ecosystem Studies in Millbrook, New York, along with colleagues from Wisconsin and Sweden, indicate that a significant part of the aquatic food chain is supported by terrestrial organic matter that originates on shore.

A building block of life, organic carbon is essential to aquatic food webs. In lakes, aquatic plants produce organic carbon by harnessing the sun’s energy (photosynthesis); some of this carbon supports the growth of fish and invertebrate populations. Scientists have long suspected that organic carbon from land is also significant to aquatic life, but the idea is difficult to demonstrate.


By tracing the fate of carbon through large-scale lake manipulations, Pace, Cole, and their colleagues have revealed that in some waters terrestrial organic carbon significantly subsidizes the aquatic food web.

"These scientists have found an ingenious method of teasing apart the carbon cycle of lakes," says James Morris, program director in the National Science Foundation (NSF)’s division of environmental biology, which funded the research. "Their study reveals a surprising degree of dependence of lake food webs on sources of organic matter transported into the lakes from the surrounding watershed. These findings reinforce the concept that the ecology of lake ecosystems is tightly coupled with that of the surrounding terrestrial landscape."

That maple tree leaves many eventually become perch, and that the vegetation around a water body can have profound impacts on the animal life within the body of water blur the perceived ecological boundaries between aquatic and terrestrial systems.

The impetus behind the study, which involved manipulating two Michigan lakes, was to better understand the aquatic food chain. Pace explains, "We wanted to reveal what many ecologists have long thought- aquatic life is partly dependent on organic matter produced in the watershed." Using a chemical tracer, Pace and his colleagues set out to quantify this assumption. "The moral of the story," Pace comments, "is, yes, fish are made from algae, but fish are also partly made from maple leaves."

In Lakes Peter and Paul located at the University of Notre Dame Research Center, the scientists tested whether lake plant production was sufficient to support resident aquatic life.

They found that 40-55 percent of particulate carbon and 2250 percent of zooplankton (small animals that live in the water column) in the lakes are derived from terrestrial sources, which confirms that terrestrial carbon fuels aquatic production. The carbon in the zooplankton reflects their dependence on both lake plant production and terrestrial organic matter. Zooplankton are a dietary staple of many fish, especially in very young life stages.

"Our results," notes Cole, "tell us there is not nearly enough aquatic carbon to support these animals. They are dependent on terrestrial inputs."

Pace comments, "We now have direct experimental evidence that confirms that aquatic food chains are supported not just by the production of plants in the water but also by the production of plants on the land surrounding lakes and ponds. The leaves and organic matter that enter lakes are ultimately incorporated into aquatic animals." These findings challenge traditional views of the aquatic food web and may help watershed managers. "Organic matter from the watershed subsidizes lake food webs, allowing more animal life in the lakes than if they were simply isolated water bodies," Pace concludes.


###
NSF program contact: James Morris, jmorris@nsf.gov.
Media contact: Cheryl Dybas, 703-292-7734, cdybas@nsf.gov.

Cheryl Dybas | NSF
Further information:
http://www.nsf.gov
http://www.nsf.gov/home/news.html

More articles from Ecology, The Environment and Conservation:

nachricht Species may appear deceptively resilient to climate change
24.11.2017 | University of California - Davis

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

IceCube experiment finds Earth can block high-energy particles from nuclear reactions

24.11.2017 | Physics and Astronomy

A 'half-hearted' solution to one-sided heart failure

24.11.2017 | Health and Medicine

Heidelberg Researchers Study Unique Underwater Stalactites

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>