Age matters when it comes to adapting to the effects of climate change

April 18, 2013

A new study of Antarctic clams reveals that age matters when it comes to adapting to the effects of climate change. The research provides new insight and understanding of the likely impact of predicted environmental change on future ocean biodiversity.

Reporting this week in the journal Global Change Biology scientists from British Antarctic Survey (BAS) and from Germany's University of Kiel and the Alfred Wegener Institute reveal that when it comes to environmental change the reaction of Antarctic clams (laternula elliptica) – a long-lived and abundant species that lives in cold, oxygen-rich Antarctic waters – is different depending on how old the animal is.

The study showed that whilst young clams (average of three years old) try to move to a better area in the sea-bed sediments when they sense warmer temperature or reduced , the older (18 years old) more sedentary clams stay put. This has implications for future clam populations because it is the older animals that reproduce. Scientists anticipate that future oceans will be slightly warmer and contains less oxygen (a condition known as hypoxia).

Lead Author Dr of said, "Antarctic clams play a vital role in the . They draw down carbon into sea-bed sediments and circulate ocean nutrients. We know that they are extremely sensitive to their environment. Our study suggests that the numbers of clams that will survive a will reduce.

"The Polar Regions are the Earth's and Antarctica is a great natural laboratory to study to future global change. These small and rather uncharismatic animals can tell us a lot about age and survival in a changing world – they are one of the 'engines of the ocean'."

Co-author, Eva Phillip, from the University of Kiel, says: "The study shows that it is important to investigate different ages of a population to understand population wide changes and responses. In respect to Antarctic clams it has been indicated in previous studies that older individuals may suffer more severely in a changing environment and the new study corroborates this assumption. Only the investigation of population-wide effects makes it possible to draw conclusions for coastal ecosystems."

Like humans, clams' muscle mass decreases as they get older. This means they get more sedentary. So when changes are introduced into their habitat, the older clams tend to just sit it out until conditions revert back to normal.

Doris Abele of the Alfred Wegener Institute in Germany says: "Our study shows that the physiological flexibility of young clams diminishes as they get older. However, the species has evolved in such a way that the fittest animals, that can tolerate life in an extreme environment, survive to reproduce into old age. Climatic change, affecting primarily the older clams, may interfere with this evolutionary strategy, with unpredictable consequences for ecosystems all around Antarctica."

Explore further: Ancient clams yield new information about greenhouse effect on climate

More information: The paper Hypoxia impacts large adults first: consequences in a warming world, is published by Global Change Biology on 18 April 2013.

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1.8 / 5 (10) Apr 18, 2013
The doomsday wishes of those making a living off hypothetical AGW, e.g. Melody Clark et al, are not coming true. The actual satellite (RSS and UAH) temperature measurements, i.e. real, hard data, have been flat for >10 yrs while 44 climate models are still predicting varying degrees of ever increasing temperatures.

Bottom line: the models grossly over estimate the positive feedback sensitivity of Earths temperature to trace gas CO2 and also use an "aerosol" negative feedback to arbitrarily dampen that effect, in spite of extensive evidence that CO2 feedback is actually negative.

So, if young clams are resilient enough to w/stand large environmental changes the species is not is danger from hypothetical AGW.
4.3 / 5 (6) Apr 18, 2013
3.7 / 5 (6) Apr 18, 2013
Yet higher and higher the UAH temps go...

Contrary to deaTard's denialist fantasies.


"The actual satellite (RSS and UAH) temperature measurements, i.e. real, hard data, have been flat for >10 yrs" - deaTard
3.9 / 5 (7) Apr 18, 2013
Bottom line is that deaTard just can't accept the fact tht UAH doesn't measure atmospheric temperaturs well due in large part due to the fact that the sensors can only measure an integrated emission from the surface of the earth to the sensor.

Surface temperatures are not measured by UAH, and neither are ocean temperatures.

"Bottom line: the models grossly over estimate the positive feedback sensitivity of Earths temperature to trace gas" - deaTard
1.7 / 5 (11) Apr 18, 2013
vandicarE is either the biggest troll or biggest retard......possibly BOTH
4.3 / 5 (6) Apr 18, 2013
VendiTard needs to educate itself.


As usual, Vendicar has his information correct.
4.4 / 5 (7) Apr 18, 2013
VENDiTARD is just an ignorant troll, not worth responding to.

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