Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

“Dead Zone” Summer Killed Billions of Ocean State Mussels

12.04.2006


A “dead zone” that formed in 2001 in Narragansett Bay left a lethal legacy, Brown University research shows. In a study of nine mussel reefs, published in Ecology, researchers report that oxygen-depleted water killed one reef and nearly wiped out the rest. A year later, only one of the nine reefs was recovering. The result was a sharp reduction in the reefs’ ability to filter phytoplankton, a process that helps control “dead zone” formation.


Dead Zone
Waves of dead mussels – researchers estimate the die-off at about 4.5 billion – washed ashore on Prudence Island, left, and elsewhere in Narragansett Bay during the summer of 2001.



Fish kills, foul odors and closed beaches hit Rhode Island’s Narragansett Bay during the summer of 2001. The culprit was hypoxia, or oxygen depletion, which literally suffocates sea life. While some evidence of this “dead zone” could be seen on the bay’s surface, Brown University ecologists went underwater and discovered a massive mussel die-off.

In a survey of nine mussel reefs located in the central bay, researchers found one reef completely wiped out. Of the remaining eight, seven were severely depleted. The ecologists estimate that the number of mussels that died was roughly 4.5 billion, or about 80 percent of the reefs’ population.


Just one month before hypoxia hit, researchers surveyed the same reefs and saw acres of healthy, densely packed mussels blanketing the estuary floor.

“What we saw was a local extinction,” said Andrew Altieri, a new Ph.D. graduate from Brown University’s Department of Ecology and Evolutionary Biology. “The mussel population was devastated. If the magnitude of this die-off was visible from the surface, there would’ve been public alarm.”

Altieri conducted the surveys with Jon Witman, a marine ecologist and an associate professor in the Department of Ecology and Evolutionary Biology. In a report on their research, published in Ecology, Altieri and Witman show that mussel die-off had a lasting effect.

In fall 2002, one year after the die-off, the pair found that only one of the nine reefs was recovering. Altieri and Witman wondered how the loss of so many mussels, which filter minute algae called phytoplankton from the water, might affect the bay’s ecosystem.

So Altieri calculated the filtering capacity of mussels in the reefs, before and after the hypoxic event. They found that the healthy mussels could filter the equivalent of the entire volume of Narragansett Bay in just 20 days. But within weeks of the die-off, that filtering capacity dropped by 75 percent.

Altieri said this is an important, and troubling, finding for water quality and sea life in the bay.

Hypoxia can start when fertilizer or sewage spills into coastal waters, carrying nitrogen, phosphorus and other nutrients. Often fueled by warm temperatures and a lack of circulation, this nutrient rush can cause algae blooms. When the algae dies, it sinks to the bottom, where it is consumed by bacteria – along with dissolved oxygen. This is what happened in Narragansett Bay in the summer of 2001 and again in the summer of 2003.

Mussels, however, can help control nutrient overload and hypoxia by consuming phytoplankton, which reduces bottom-dwelling bacteria. “When we lose mussels, we may be losing the ability to prevent future dead zones from forming,” Altieri said. “So these sorts of extinctions may trigger a downward spiral, with coastal zones less able to handle environmental degradation.”

According to a 2004 United Nations Environment Program report, the number of areas hit by hypoxia worldwide has doubled since 1990. “Dead zones” can be found along the east coast of the United States, in the seas of Europe, as well off Australia, Brazil, and Japan. One of the biggest “dead zones” is in the Gulf of Mexico, where it has grown to an area as big as New Jersey.

Altieri and Witman said lessons from Narragansett Bay could be applied to other “dead zones.”

“When you lose a foundation species such as mussels – which filter water and provide food and habitat for other organisms – you see a large and lasting effect on the ecosystem,” Witman said. Added Altieri: “We’ve already seen this in Chesapeake Bay and other coastal estuaries, where loss of filter-feeding oysters has led to runaway effects of pollution and hypoxia and prevented restoration of these shellfish.”

The National Oceanic and Atmospheric Administration, the Andrew Mellon Foundation, and Rhode Island Sea Grant funded the work.

The Ecology paper is available online.

Wendy Lawton | EurekAlert!
Further information:
http://www.brown.edu

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>