Pteropods from the Caribbean Sea: variations in calcification as an indicator of past ocean carbonate saturation (update)

The aragonite shell-bearing thecosome pteropods are an important component of the oceanic plankton. However, with increasing pCO₂ and the associated reduction in oceanic pH (ocean acidification), thecosome pteropods are thought to be particularly vulnerable to shell dissolution. The distribution and preservation of pteropods over the last 250 000 years have been investigated in marine sediment cores from the Caribbean Sea close to the island of Montserrat. Using the Limacina Dissolution Index (LDX), fluctuations in pteropod calcification through the most recent glacial/interglacial cycles are documented. By comparison to the oxygen isotope record (global ice volume), we show that pteropod calcification is closely linked to global changes in pCO₂ and pH and is, therefore, a global signal. These data are in agreement with the findings of experiments upon living pteropods, which show that variations in pH can greatly affect aragonitic shells. The results of this study provide information which may be useful in the prediction of future changes to the pteropod assemblage caused by ocean acidification.

Ocean Acidification and the Weskeag

Friends of the Weskeag will host a public informational meeting about Ocean Acidification and the Georges River and Weskeag Estuaries — what we need to know, how we can find out, and how citizens can participate. The meeting will take place at 6:30PM Thursday January 26 at the Wessaweskeag Historical Society in South Thomaston.

Jon Eaton, Georges River Tidewater Association (GRTA), and Sherm Hoyt, Fisheries Outreach Coordinator for Maine Sea Grant and Cooperative Extension, will discuss plans for a new citizen monitoring program and how this can be applied to the Weskeag. GRTA has been developing this monitoring program over the past several months with generous assistance from the Friends of Casco Bay, the Gulf of Maine Council on the Marine Environment, and the Maine Department of Environmental Protection. The advisory committee for this program includes some of Maine’s top marine scientists and shoreline stewards. Monitoring begins in spring 2012, to track pH, dissolved oxygen, total nitrogen, chlorophyll, turbidity, temperature, and salinity in the estuary.

Losing Nemo

Sometimes this blog may give the impression that it doesn’t take the threat of man-made global warming all that seriously. But today all cynicism and scepticism must come to an end.

How can any of us in all conscience drive a car or fly on holiday or even take a shower EVER again when scientists have discovered the most horrific evidence yet of the apocalyptic damage down by anthropogenic CO2: (H/T M. Potts)

It can make clownfish go a bit weird. Apparently.

 

Philip Munday and colleagues at James Cook University in Townsville, Queensland, Australia, have previously found that if you put reef fish into water with more CO₂ than normal in it – similar to the levels expected in oceans by the end of the century – they become bolder and attracted to odours they would normally avoid, including those of predators and unfavourable habitats.

Munday and his colleague Göran Nilsson at the University of Oslo, Norway, have now discovered that CO₂ leads to riskier behaviour by interfering with a neurotransmitter receptor called GABA-A.