Up to 75 percent of the offspring of small crustaceans that feed on a common brown seaweed, for example, are killed when they are exposed to copper at levels found in some parts of the harbour, UNSW laboratory and field experiments have shown.
The UNSW study sampled seaweed from 10 bays within the harbour, ranging from 3km to 11km from Sydney Heads. Concentrations of copper, lead and zinc in a species of brown seaweed found in Woolloomooloo Bay, Balls Head Bay and Rushcutters Bay equal or exceed levels found in the Hong Kong Islands and Brazil's Sepetiba Bay, which are among the world's most heavy metal-contaminated waterways.
Heavy metals such as copper, lead and zinc find their way into Sydney Harbour from stormwater runoff, industrial waters and motorised watercraft. These seaweeds "bioaccumulate" metals inside their tissues and scientists use them to monitor environmental pollutants.
Published in an upcoming issue of the journal Environmental Pollution, it is the first investigation of the geographic relationship between metal contamination in seaweeds and the crustaceans that feed on them.
The study reveals that high concentrations of copper in one seaweed species (Padinacrassa) were associated with a low abundance of grazing amphipods - small shrimp-like creatures - that feed on algae. These creatures are highly abundant in all marine habitats: on average there are some 6,000 animals per square metre of algal bed in Sydney Harbour.
"The habitats that we sampled within Sydney Harbour contain among the highest concentrations of metals yet identified in brown seaweeds," says study lead author, Dr David Roberts.
"In seven of the 10 sample harbour sites, we measured copper concentrations in one seaweed species that exceeded levels known to threaten small crustaceans. These concentrations exceed all previously scientifically reported levels."
David Roberts | EurekAlert!
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Value from wastewater
16.08.2017 | Hochschule Landshut
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences