Meeting Abstract
P2.43 Sunday, Jan. 5 15:30 Testing the waters: Seasonal seawater carbonate chemistry baseline to inform biological ocean acidification experiments on the western Antarctic Peninsula SCHRAM, J.B.*; SCHOENROCK, K.M; AMSLER, M.O.; AMSLER, C.D.; MCCLINTOCK, J.B.; ANGUS, R.A.; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham jbschram@uab.edu
Marine organisms in the Southern Ocean are faced with comparatively rapid ocean acidification (OA) due to the high solubility of carbon dioxide at low temperature and regional ocean circulation patterns. Moreover, most Antarctic marine invertebrates are weakly calcified making them highly vulnerable to shell dissolution. To date, experimental OA research in Antarctica has relied on setting control and experimental pH levels based on models of global ocean averages. Assessments of ambient pH and other parameters of seawater chemistry in Antarctic seas are few and those studies conducted have been performed in seasonally ice free waters (Ross Sea & Prydz Bay) or over relatively short time periods, under sea-ice during the austral spring/summer (McMurdo Sound). Here we present data collected over a full year for nearshore benthic seawater (pH, total alkalinity, temperature, and calculated carbonate chemistry) along the coast of Anvers Island on the western Antarctic Peninsula (near-shore open water with brief, transient exceptions in winter months). Seawater samples were collected at three sampling frequencies: once daily, twice daily, and weekly. Median seawater pH over the year was 8.08 and relatively stable with the exception of an increase in the austral spring/summer (median 8.21 pH). This seasonal increase in pH is likely the result of both abiotic (melting sea ice) and biotic (phytoplankton bloom) factors. The seawater chemistry established in the present study is important in contextualizing and setting parameters for laboratory OA experiments for marine organisms of the Antarctic Peninsula. Supported by NSF grant ANT-1041022.
