Glacial–interglacial surface water variations in the Caribbean Sea during the last 300 ky based on calcareous nannofossil analysis

Kameo, Koji; Shearer, Michelle C.; Droxler, André W.; Mita, Isao; Watanabe, Rika; Sato, Tokiyuki

doi:10.1016/j.palaeo.2004.05.017

Cited by 21 publications

(15 citation statements)

References 23 publications

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“…The salinity maximum at mid-depth is indicative of the Subtropical Underwater layer, formed when evaporation increases salinity in Sargasso Sea surface water. This layer is relatively nutrient rich (Kameo et al, 2004). Because of its higher density, this intermediate water mass sinks below the surface water and overlays fresher but colder water below (Worthington, 1982;O'Connor et al, 2005).…”

Section: Resultsmentioning

confidence: 99%

Composition and enzymatic function of particle-associated and free-living bacteria: a coastal/offshore comparison

et al. 2014

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We compared the function and composition of free-living and particle-associated microbial communities at an inshore site in coastal North Carolina and across a depth profile on the Blake Ridge (offshore). Hydrolysis rates of six different polysaccharide substrates were compared for particle-associated (43 lm) and free-living (o3 to 0.2 lm) microbial communities. The 16S rRNA-and rDNA-based clone libraries were produced from the same filters used to measure hydrolysis rates. Particle-associated and free-living communities resembled one another; they also showed similar enzymatic hydrolysis rates and substrate preferences. All six polysaccharides were hydrolyzed inshore. Offshore, only a subset was hydrolyzed in surface water and at depths of 146 and 505 m; just three polysaccharides were hydrolyzed at 505 m. The spectrum of bacterial taxa changed more subtly between inshore and offshore surface waters, but changed greatly with depth offshore. None of the OTUs occurred at all sites: 27 out of the 28 major OTUs defined in this study were found either exclusively in a surface or in a mid-depth/bottom water sample. This distinction was evident with both 16S rRNA and rDNA analyses. At the offshore site, despite the low community overlap, bacterial communities maintained a degree of functional redundancy on the whole bacterial community level with respect to hydrolysis of high-molecular-weight substrates.

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Section: Resultsmentioning

confidence: 99%

Composition and enzymatic function of particle-associated and free-living bacteria: a coastal/offshore comparison

et al. 2014

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“…During low sea levels the Cariaco Basin was isolated from the open Caribbean by the shallower sills, restricting the import of nutrient-rich subsurface waters (i.e., Subtropical Underwater [cf. Kameo et al, 2004]), and keeping the MIS 4 productivity levels below those of MIS 3. However, the intensity of upwelling-favorable winds during sea level highstands would have had an additional effect on the productivity intensity and the establishment of bottom water anoxia at shorter time scales.…”

Section: Mis 3/mis 4 and Orbital-scale Variabilitymentioning

confidence: 99%

“…In spite of the significant role that the Caribbean Sea plays in the heat and mass transport from the tropics to higher latitudes [e.g., Gordon, 1967;Metcalf, 1976;Mooers and Maul, 1998;Schmidt et al, 2004], studies on late Quaternary paleoproductivity in this region are scarce [J. I. Kameo et al, 2004]. The Caribbean Sea is generally characterized by nutrientdepleted surface waters.…”

Section: Introductionmentioning

confidence: 99%

Reconstructing marine productivity of the Cariaco Basin during marine isotope stages 3 and 4 using organic‐walled dinoflagellate cysts

et al. 2008

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[1] An organic-walled dinoflagellate cyst analysis was carried out on sediment core MD03-2622, retrieved from the Cariaco Basin. The core comprises the 73-30 ka interval. Down core changes in cyst abundance, accumulation rate, and composition of cyst assemblages were used to identify climatic and oceanographic changes at orbital and millennial time scales in this near-equatorial seasonal upwelling area. Throughout the sequence, dinoflagellate cyst assemblages were dominated by heterotrophic dinocysts (mainly Brigantedinium spp.), with the exception of four autotrophic-dominated (mainly Spiniferites ramosus) intervals around 58, 53, 46, and 37 ka. At orbital time scales, changes in the dinoflagellate productivity seem to follow low-latitude insolation, with the highest productivities coinciding with maximum February insolation (47-38 ka). At millennial scales, cyst accumulation rates appeared to coincide with Dansgaard-Oeschger (D-O) variability, with significant increments occurring during warm interstadials. The opposite was true during stadials. Short periods of high nutrient availability and stratified conditions followed Heinrich events H4, H5, H5a, and H6 and concurred with enhanced river runoff. Spectral analyses confirm the existence of these and other higherfrequency periodicities and support the idea of a tightly coupled terrestrial/marine and tropical/high-latitude climate system during the last glacial period.Citation: González, C., L. M. Dupont, K. Mertens, and G. Wefer (2008), Reconstructing marine productivity of the Cariaco Basin during marine isotope stages 3 and 4 using organic-walled dinoflagellate cysts, Paleoceanography, 23, PA3215,

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“…Core 999A was raised from the Kogi Rise at a depth of 2,827 m, about 1000 m above the turbidite-laden floor of the Colombian Basin [Mutti, 2000]. The site is directly influenced by the warm Caribbean Current and is ideally suited to reconstruct changes in southern Caribbean surface water hydrography as demonstrated by the recent study of calcareous nannofossil populations over the same interval at Site 999A [Kameo et al, 2004].…”

Section: Study Area and Itcz Variationmentioning

confidence: 99%

Western Caribbean sea surface temperatures during the late Quaternary

Schmidt

Vautravers

Spero

2006

Geochem Geophys Geosyst

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[1] Mg/Ca ratios in the planktonic foraminifera Globigerinoides ruber from Colombian Basin core ODP 999A suggest that Caribbean sea surface temperatures (SSTs) were from 2.1 to 2.7°C colder than the present during the last three glacial maximums. In comparison, faunal derived SSTs (SIMMAX method) show that August SSTs in the Caribbean varied <2°C over the past 360 kyr, whereas February SSTs varied between 21.0°C and 26.5°C. Changes in the Mg/Ca-SST record contain a strong 23 kyr periodicity, suggesting the Mg/Ca-SST record reflects a warm season weighted SST average rather than an annual mean SST. Combining several dissolution indices, we identify brief periods of decreased carbonate preservation in our record and show that MIS 11 stands out as the most intensive dissolution cycle in the Caribbean over the last 460 kyr. Comparison of Caribbean SST change with a similar estimate of tropical SST variability in the western Pacific over the past 360 kyr reveals shifts in the east-west tropical SST gradient that are coeval with glacial-interglacial climate change and consistent both with a southward migration of the glacial ITCZ and with a glacial El Niño-like mode of tropical circulation.

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Glacial–interglacial surface water variations in the Caribbean Sea during the last 300 ky based on calcareous nannofossil analysis

Cited by 21 publications

References 23 publications

Composition and enzymatic function of particle-associated and free-living bacteria: a coastal/offshore comparison

Composition and enzymatic function of particle-associated and free-living bacteria: a coastal/offshore comparison

Reconstructing marine productivity of the Cariaco Basin during marine isotope stages 3 and 4 using organic‐walled dinoflagellate cysts

Western Caribbean sea surface temperatures during the late Quaternary

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