Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nutrient pollution causes a long-term effect on Chesapeake Bay ecosystem

29.11.2005


A team of scientists has determined that the growing worldwide problem of increased nutrient pollution, primarily nitrogen and phosphorous, on coastal waterways has altered the ecology of Chesapeake Bay as reported in the most recent issue of Marine Ecology Progress Series.



During the last 50 years, nutrient enrichment has reduced the size of sea grass beds and lowered dissolved oxygen concentrations, both contributing to the degradation of bottom habitats. Excess nutrients can cause large algae blooms which cloud the water. When the algae bloom dies it sinks to the bottom and decays through bacterial processes that rapidly deplete dissolved oxygen. Significant increases in the organic content of 200 year-old sediment suggest stimulation of algae blooms during pre-industrial times. Lead author Dr. W. Michael Kemp, of the University of Maryland Center for Environmental Science, said "By studying long-term effects of nutrient enrichment and detailed processes by which coastal ecosystems have been altered, we will be far better positioned to effect restoration of the estuary’s valuable resources."

These trends have been made even worse by declines in oyster beds, caused by overfishing and disease. The oyster was considered one of the Bay’s dominant bottom feeders consuming vast amounts of algae. Extensive tidal marshes, which serve as effective nutrient buffers, are now being lost due to rising sea levels thus making the problems of nutrient loading even worse.


While the total fish production in the Bay is not believed to have declined, the type of fish have changed. Fish populations have shifted from species living near the seabed to those living in the upper waters. This shift may lead to food chain inefficiencies that favor production of bacteria and small invertebrates.

Even in some Chesapeake Bay tributaries such as the Potomac and Patuxent Rivers, where significant nutrient pollution reductions have occurred, complex ecological relationships have not been fully restored. For example, while algae blooms decreased in the Patuxent River with decreasing nutrients in the last fifteen years, the bottom water dissolved oxygen levels are still very low. Sea grass beds have not increased even with replanting.

The authors cited that an important component of the Chesapeake restoration effort is to revitalize its habitats. Kemp stated, "Even small increases in sea grass beds, oyster reefs, and tidal marshes may lead to substantial benefits toward recovery from nutrient enrichment due to their secondary effects. These habitats filter nutrients out of the system as well as trap and bind fine sediment particles. They support positive-feedback mechanisms that tend to accelerate Bay restoration once the reversal has been set in motion."

David Nemazie | EurekAlert!
Further information:
http://www.chesapeakebay.net/
http://www.umces.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Extensive Funding for Research on Chromatin, Adrenal Gland, and Cancer Therapy

28.06.2017 | Awards Funding

Predicting eruptions using satellites and math

28.06.2017 | Earth Sciences

Extremely fine measurements of motion in orbiting supermassive black holes

28.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>