Mairi Best

Current area of research:

Skeletal carbonate is our primary source of paleo-biological information, and the primary means by which carbon is transferred from the atmosphere-ocean to the lithosphere. As such, processes which control its preservation and fidelity (i.e. taphonomy) are of primary importance to interpreting the skeletal record and the carbon cycle. My research quantifies taphonomic processes and potential preservation (mega-) biases at scales ranging from within individual environments to across latitudes, with a focus on coastal settings as the main locus of global elemental exchange and anthropogenic impact. I use integrated datasets on A) the macroscopic, microstructural, and chemical transformation of experimentally deployed shell material, B) the macroscopic and microscopic postmortem condition and the age distribution of naturally occurring death assemblages, and C) the environment of deposition in order to:

• Document patterns, agents, and rates of skeletal modification with the goal of testing for megabias
• Test the fidelity of skeletal carbonate chemical signatures to original water masses and link chemistry to microstructural changes
• Determine scales of time averaging in recent shelf sediments to assess temporal resolution and stratigraphic disorder
• Document controls on carbonate burial and model predictions for global patterns of carbonate preservation
• Develop the use of skeletal death assemblages in environmental assessment employing A) live/dead fidelity, B) correlations of shell damage with environmental variables, and C) invasive species

Over the past 18 years I have built up expertise, samples and data from the following locations as a foundation for these latitudinal comparisons: Tropical: PNG, Australia, Seychelles, Panama, St Lucia, Barbados, Nicaragua, Bahamas; Temperate: Bay of Fundy, Scotian Shelf, Long Island Sound, Vancouver Island (Rupert Inlet, Bamfield, and Saanich Inlet), Northern Ontario; Polar: Canadian Arctic (Resolute and Beaufort) and Antarctica (McMurdo Sound). This gives me a privileged perspective and the means to test for global trends in skeletal carbonate preservation in modern environments.

Megabias along latitudes or other environmental gradients has significant implications for how we interpret changes in biodiversity for example during past climate changes, with a view of forecasting biotic response to future changes. It also is key to assembling a global model of carbonate burial in shelf environments, currently poorly constrained but estimated to control half of the total carbonate burial, the main carbon sink of the carbon cycle. As this model will be based on environmental variability, it can also predict the response to large scale environmental change associated with climate change. This is particularly important in the face of ocean acidification, and for arctic regions, where the greatest climate fluctuation is predicted.

Selected publications:

Best, M.M.R. in press. Contrast in preservation of bivalve death assemblages in siliciclastic and carbonate tropical shelf settings. Palaios.

Best, M.M.R., B. D. Bornhold, S. K. Juniper and C. R. Barnes 2007. NEPTUNE Canada Regional Cabled Observatory: Science Plan. Proceedings of the Oceans 2007 International meeting of the Marine Technology Society and the Institute of Electrical and Electronics Engineers, October 2007.

Best, M.M.R., Ku, T.C.W., Kidwell, S.M., and Walter, L.M. 2007. Carbonate preservation in shelf environments: Unexpected role of tropical siliciclastics. Journal of Geology, 115: 437-456.

Kidwell, S.M., Best, M.M.R., and Kaufman, D.S. 2005. Taphonomic tradeoffs in tropical marine death assemblages: Differential time-averaging, shell loss, and probable bias in siliciclastic versus carbonate facies. Geology 33(9): 729-732.

Best, M.M.R., Burniaux, P., and Pandolfi, J.M. 2004. Experimental Bivalve Taphonomy in Reefs of Madang Lagoon, Papua New Guinea. In Best, M.M.R., and Caron, J.-B. 2004. eds. Canadian Paleontology Conference Proceedings No. 2, GAC publications, p.8-12.

Chmura, G.L., Best, M.M.R., and Noel, P. 2004. Intertidal environments at Dipper Harbour, Bay of Fundy. In Caron, J.-B. and Best, M.M.R. 2004. eds. Canadian Paleontology Conference Field Trip Guidebook No. 10, GAC publications, p.4-15.

Kidwell, S.M., Rothfus, T.A., and Best, M.M.R., 2001. Sensitivity of taphonomic signatures to sample size, sieve size, damage scoring system, and target taxa. Palaios 16(1).

Edinger, E.N. and Best, M.M.R., 2001. Environmental impacts of nickel mining in Soroako, Sulawesi, Indonesia. Report to Miningwatch Canada, 20p.+ maps & plates.

Best, M.M.R. and Kidwell, S.M. 2000a. Bivalve taphonomy in tropical mixed siliciclastic-carbonate settings: I. Environmental variation in shell condition. Paleobiology 26(1):80-102.

Best, M.M.R. and Kidwell, S.M. 2000b. Bivalve taphonomy in tropical mixed siliciclastic-carbonate settings: II. Effect of bivalve life habits and shell types. Paleobiology 26(1):103-115.

D'Croz, L., Jackson, J.B.C., and Best, M.M.R. 1998. Siliciclastic-carbonate transitions along shelf transects through the Cayos Cochinos Archipelago, Honduras. Revista de Biologia Tropical 46 Supl.(4):57-66.

Pandolfi, J.M., Best, M.M.R., and Murray, S.P. 1994. Coseismic Event of May 15, 1992, Huon Peninsula, Papua New Guinea: Comparison with Quaternary Tectonic History. Geology 22:239-242.