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Interannual variability of pteropod shell weights in the high-CO2 Southern Ocean
Citation
Roberts, D and Howard, W and Moy, AD and Roberts, JL and Trull, T and Bray, SG and Hopcroft, RR, Interannual variability of pteropod shell weights in the high-CO2 Southern Ocean, Biosciences Discussions, 5, (Special Issue 43) pp. 4453-4480. ISSN 1810-6277 (2008) [Non Refereed Article]
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Copyright Statement
© Author(s) 2008. This work is distributed under the Creative Commons Attribution 3.0 License.
Official URL: http://www.biogeosciences.net/
Abstract
Anthropogenic inputs of CO2 are altering ocean chemistry and may alter the role of
marine calcifiers in ocean ecosystems. CO2 emissions over the coming centuries may
produce changes in ocean pH not seen for millions of years. Laboratory evidence
5 has shown decreased calcification in some species of coccolithophores, foraminifera,
corals and pteropods in response to CO2 enrichment. However, in situ observations
of calcification in marine organisms are limited, especially for the aragonitic pteropods.
This group of pelagic molluscs are likely to be more sensitive to changes in carbonate
chemistry than calcite producers such as foraminifera and coccolithophores. Here
10 we present observations of pteropod shell-weight and flux from 19972006 in sediment
traps deployed at 47 S, 142 E at 2000 meters below sea surface in the Southern
Ocean. A decadal trend of 1.17±0.47 μg yr−1 (P =0.02) in mean shell weight in the
pteropod Limacina helicina antarctica forma antarctica suggests a small but detectable
reduction in calcification. Gaps in the data make it difficult to state with certainty the
15 significance of the trend. However, this data set represents the first attempt to estimate
interannual variations in pteropod calcification and establish a benchmark against
which future impacts of ocean acidification may be detected. Contributions of Limacina
helicina antarctica morphotypes to the total pteropod flux were also reduced over the
decade. We suggest these small though discernible trends are due to changing car20
bonate chemistry in the Subantarctic, as other oceanographic variables show no clear
decadal trends. With CO2 continuing to enter the ocean such impacts on pteropods
and other marine calcifiers could result in changes to the distribution of species and
the structure of Southern Ocean ecosystems.
Item Details
| Item Type: | Non Refereed Article |
|---|---|
| Research Division: | Earth Sciences |
| Research Group: | Atmospheric Sciences |
| Research Field: | Climate Change Processes |
| Objective Division: | Environment |
| Objective Group: | Climate and Climate Change |
| Objective Field: | Climate and Climate Change not elsewhere classified |
| UTAS Author: | Roberts, D (Dr Donna Roberts) |
| UTAS Author: | Howard, W (Associate Professor William Howard) |
| UTAS Author: | Moy, AD (Dr Andrew Moy) |
| UTAS Author: | Roberts, JL (Dr Jason Roberts) |
| UTAS Author: | Trull, T (Professor Thomas Trull) |
| UTAS Author: | Bray, SG (Mr Stephen Bray) |
| ID Code: | 56332 |
| Year Published: | 2008 |
| Deposited By: | IASOS |
| Deposited On: | 2009-04-22 |
| Last Modified: | 2011-09-06 |
| Downloads: | 497 View Download Statistics |
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