Degradation rates and productivity signals of organic-walled dinoflagellate cyst species in surface sediment samples


To understand the role of the ocean within the global carbon cycle, detailed information is required on key-processes within the marine carbon cycle; bio-production in the upper ocean, export of the produced material to the deep ocean and the storage of carbon in oceanic sediments. Quantification of these processes requires the separation of signals of net primary production and the rate of organic matter decay as reflected in fossil sediments. This study examines the large differences in degradation rates of organic-walled dinoflagellate cyst species to separate these degradation and productivity signals. For this, accumulation rates of cyst species known to be resistant (R-cysts) or sensitive (S-cysts) to aerobic degradation of 62 sites are compared to mean annual chlorophyll-a, sea-surface temperature, sea-surface salinity, nitrate and phosphate concentrations of the upper waters and deep-water oxygen concentrations. Furthermore, the degradation of sensitive cysts, as expressed by the degradation constant k and reaction time t, has been related to bottom water [O2]. The studied sediments were taken from the Arabian Sea, north-western African Margin (North Atlantic), western-equatorial Atlantic Ocean/Caraibic, south-western African margin (South Atlantic) and Southern Ocean (Atlantic sector).Significant relationships are observed between (a) accumulation rates of R-cysts and upper water chlorophyll-a concentrations, (b) accumulation rates of S-cysts and bottom water [O2] and (c) degradation rates of S-cysts (kt) and bottom water [O2].Relationships that are extremely weak or are clearly insignificant on all confidence intervals are between (1) S-cyst accumulation rates and chlorophyll-a concentrations, sea-surface temperature (SST), sea-surface salinity (SSS), phosphate concentrations (P) and nitrate concentrations (N), (2) between R-cyst accumulation rates and bottom water [O2], SST, SSS, P and N, and between (3) kt and water depth. Co-variance is present between the parameters N and P, N, P and chlorophyll-a, oxygen and water depth. Correcting for this co-variance does not influence the significance of the relationship given above.The possible applicability of dinoflagellate cyst degradation to estimate past net primary production and deep ocean ventilation is discussed.

Supplement to: Zonneveld, Karin A F; Bockelmann, Frank Detlef; Holzwarth, Ulrike (2007): Selective preservation of organic-walled dinoflagellate cysts as a tool to quantify past net primary production and bottom water oxygen concentrations. Marine Geology, 237(3-4), 109-126

Related Identifier IsSupplementTo
Metadata Access
Creator Zonneveld, Karin A F ORCID logo; Bockelmann, Frank Detlef ORCID logo; Holzwarth, Ulrike
Publisher PANGAEA
Publication Year 2007
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 594 data points
Discipline Earth System Research
Spatial Coverage (-59.388W, -42.045S, 66.033E, 32.182N); Walvis Ridge; Namibia continental slope; Namibia Continental Margin; Northern Cape Basin; Northeast Brasilian Margin; Atlantic Caribbean Margin; Agadir Canyon; Central South Atlantic
Temporal Coverage Begin 1992-01-07T00:00:00Z
Temporal Coverage End 2000-03-04T02:21:00Z