Picture Climate: How We Can Learn From Corals

Friday, August 16, 2013
Coral ecosystem: Photo courtesy of NOAA

Scientists study coral reefs to learn about climate change and to make predictions – NOAA explains:

Coral reefs support one of the most diverse ecosystems in the world with thousands of species relying on the delicate reefs for survival. How can scientists learn about climate from these beautiful and essential underwater ecosystems? Many coral reefs have been around for millions of years, yet they are extremely sensitive to changes in climate conditions. Corals are affected by ocean warming (sometimes bleaching when temperatures rise or fall), by pollution and runoff, and by changes in the pH of seawater, which decreases as more carbon dioxide enters the ocean—a trend known as Ocean Acidification.

As corals grow, they form skeletons by making calcium carbonate from the ocean waters. The density of these calcium carbonate skeletons changes as the water temperature, light, and nutrient conditions change, giving coral skeletons formed in the summer a different density than those formed in the winter. These seasonal variations in density produce growth rings similar to those in trees. Scientists can study these rings and other characteristics to determine the climatic conditions during the seasons in which the coral grew. These growth bands also allow scientists to date coral samples to an exact year and season.

To gather data and information about coral growth bands, scientists jump in their scuba gear and dive down among the reefs. Once in position, they use a hollow, diamond-tipped drill bit to gather small core samples from the corals without injuring the animal. Sometimes the banding patterns in these samples are evident by visual inspection alone, but often scientists use x-ray imaging software to get a look at the patterns. The scientists then mark the varying layers by year and season and extract samples from the layers for precise chemical analysis.

Analyzing the composition of trapped oxygen atoms for example, is used to estimate seasonal temperature and rainfall and to build a record of how they have changed through time. Times of environmental stress, including disease outbreaks or bleaching— when a coral animal expels the symbiotic algae that lives within it and gives it its color—can also be identified within the banding. Such markers help scientists determine extreme climate conditions that are harmful to the reef.

By using corals to determine the past climate in the tropical oceans, scientists can also predict future trends in the climate system. The information corals provide about the tropical oceans can be very useful in examining the El Niño Southern Oscillation . El Niño, which is spawned in the Pacific Ocean, greatly affects weather from Asia and Australia to North and South America. By sampling corals in the Pacific, scientists can determine El Niño patterns over the past few hundred years and use that information to improve predictions about future episodes and changes in this natural climate pattern.

Source: NOAA


Maritime Today

The Maritime Industry's original and most viewed E-News Service

Maritime Reporter November 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds


Bill on Danish Maritime Planning Submitted

The bill is to form the basis of a maritime planning act intended to promote economic growth and development of sea areas. The Danish Maritime Authority is to head the work.

Seaspan Implements ECO Insight solution

Seaspan Ship Management Ltd. will implement the DNV GL fleet performance management solution ECO Insight to improve their fleet monitoring. ECO Insight will

New Appoitments at Becker Marine Systems USA

Becker Marine Systems USA continues growth in North America. Becker Marine Systems, the leader in rudder technology and the inventor of the Becker Mewis Duct


Plans to Create Rio Doce Fund

Vale and BHP Billiton announced today plans to work together, with Samarco, to establish a voluntary, non-profit fund to support the rescue and recuperation of the Rio Doce river system,

Canada to Aid Developing Nations Fight Climate Change

Canada will provide aid to developing countries to combat climate change, Prime Minister Justin Trudeau announced on Friday ahead of talks on global warming,

Sandra Weakens to Tropical Storm off Mexico's Coast

Hurricane Sandra weakened to a tropical storm on Friday and was expected to continue losing strength as it approached Mexico's Pacific coast, the U.S. National Hurricane Center (NHC) said.

Marine Science

Rates, Fees of Danish Maritime Authority to be Revised

A number of fee rates within the Danish Maritime Authority's area will be changed from 2016. The price schedule is available from the webpage of the Danish Maritime Authority.

Henriksen Unveils Strongest SOLAS Boat Lifting Hook

H Henriksen of Norway has received SOLAS certification for a new off-load single-point boat lifting hook capable of holding up to 22.5-tonnes. The quick release

Norwegian Escape with Biggest Scrubbers sets Sail

On a sunny October day in the German harbor-town of Hamburg, M/V Norwegian Escape, a brand new cruise ship, sets sail for the first time. On board are five Yara SOx scrubbers – one for each engine.

Maritime Contracts Maritime Security Maritime Standards Navigation Salvage Ship Electronics Ship Repair Shipbuilding / Vessel Construction Sonar Winch
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.0825 sec (12 req/sec)