Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Mercury contamination found in stranded Victorian dolphins

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

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 (

"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.

Samantha Blair | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>