Coralline red algae as high-resolution climate recorders
Abstract
Most high-resolution, proxy-based paleoclimate research hasconcentrated on tropical oceans, while mid- and high-latitudemarine regions have received less attention, despite their importancein the global climate system. At present, sclerochronologicalanalyses of bivalve mollusks supply the bulk of annual- to subannual-resolutionextratropical marine climate data, even though interpretationis complicated by a slowdown of growth with increasing shellage. Hence, in order to address the need for additional high-resolutionproxy climate data from extratropical regions, we conductedthe first year-long in situ field calibration of the corallinered alga Clathromorphum compactum in the Gulf of Maine, UnitedStates. Coralline red algae are widely distributed in coastalregions worldwide, and individual calcified plants can livecontinuously for several centuries in temperate and subarcticoceans. Stable oxygen isotopes extracted at subannual resolutionfrom growth increments of monitored specimens of C. compactumrelate well to in situ-measured sea-surface temperaturesduring the May to December calcification period, highlightingthe suitability of coralline red algae as an extratropical climatearchive. Furthermore, there is a strong correlation betweena 30 yr <IMG SRC="/math/sigma.gif" ALT="{sigma}" BORDER="0">18O record of C. compactum and an instrumental sea-surfacetemperature record (r = -0.58, p = 0.0008) and a proxyreconstruction derived from the bivalve Arctica islandica collectedin the central Gulf of Maine (r = 0.54, p = 0.002).
- Publication:
-
Geology
- Pub Date:
- June 2008
- DOI:
- 10.1130/G24635A.1
- Bibcode:
- 2008Geo....36..463H