Featured Research

from universities, journals, and other organizations

Mercury Contamination Found In Stranded Victorian Dolphins

Date:
June 11, 2008
Source:
Monash University
Summary:
Research by an honors student has revealed high mercury levels may be a contributing factor to dolphin deaths in Australia.

Monash University research into heavy metal contaminant levels in dolphins from Port Phillip Bay and the Gippsland Lakes has revealed high mercury levels may be a contributing factor to dolphin deaths.

Researchers from the School of Biological Sciences have confirmed levels of mercury found in the dolphins were within a range considered to cause negative health and mental effects and were higher than mercury levels found in populations around the world.

Supervisory researcher Dr Ross Thompson said the mercury concentrations in 20 live and eight dolphins which died after becoming stranded, collected over the last two years, were measured by Honours student Alissa Monk. Levels in the dead dolphins averaged 3.45 milligrams of mercury per kilogram of tissue compared to 1.32 mg/kg in living dolphins.

"Mercury levels detected are sufficient to cause significant health impacts and were comparable to those found in areas of the world that are considered highly polluted, including the Mediterranean Sea," Dr Thompson said.

Mercury has been shown in previous national studies to bioaccumulate in dolphins, but this is the first study to find particularly high levels in stranded animals in coastal Victoria. Bioaccumulation is the food chain process whereby smaller fish containing mercury are eaten by larger mercury contaminated fish, which are then consumed by dolphins, who can consume up to ten kilograms of fish a day. Mercury levels found in fish were considered low (<0.5 mg/kg) and were fine for human consumption.

"Dolphins may be becoming stranded as a direct consequence of mercury contamination which damages their neurological system. They become potentially confused and disorientated, and strand themselves. Even the apparently healthy dolphins had high levels of mercury which put them at risk of future health complications," Dr Thompson said.

Dr Thompson said mercury is likely to have come from the sediments of the Bay and researchers are concerned that dredging activities may increase the dolphins' exposure.

"Sediment contains mercury, which is likely to have originated from historical gold mining sites where mercury was used in gold processing, as well as from other industrial sources. Over time, the mercury has been washed down through waterways, including the Yarra River, and come to rest on the bottom of the Bay," Dr Thompson said.

Dr Thompson said it was critical that further studies were done throughout the bay dredging process to ensure any further decline in dolphin health could be identified and managed.

The School of Biological Sciences research was supported by Coastcare, West Gippsland CMA, the Gippsland Lakes Board and the Dolphin Research Institute.


Story Source:

The above story is based on materials provided by Monash University. Note: Materials may be edited for content and length.


Cite This Page:

Monash University. "Mercury Contamination Found In Stranded Victorian Dolphins." ScienceDaily. ScienceDaily, 11 June 2008. <www.sciencedaily.com/releases/2008/06/080610092720.htm>.
Monash University. (2008, June 11). Mercury Contamination Found In Stranded Victorian Dolphins. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2008/06/080610092720.htm
Monash University. "Mercury Contamination Found In Stranded Victorian Dolphins." ScienceDaily. www.sciencedaily.com/releases/2008/06/080610092720.htm (accessed April 16, 2014).

Share This



More Plants & Animals News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Couples Who Sleep Less Than An Inch Apart Might Be Happiest

Couples Who Sleep Less Than An Inch Apart Might Be Happiest

Newsy (Apr. 16, 2014) A new study by British researchers suggests couples' sleeping positions might reflect their happiness. Video provided by Newsy
Powered by NewsLook.com
Passengers Abuzz After Plane Hits Swarm of Bees

Passengers Abuzz After Plane Hits Swarm of Bees

AP (Apr. 16, 2014) An Allegiant Airlines plane from Las Vegas to Duluth, Minnesota turned around shortly after take-off, after a swarm of bees clouded the windshield and got sucked into the engines. (April 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins