Successional blooms of alkenone‐producing haptophytes in Lake George, North Dakota: Implications for continental paleoclimate reconstructions
Theroux, S.; Huang, Y.; Toney, J.L.; Andersen, R.; Nyren, P.; Bohn, R.; Salacup, J.; Murphy, L.; Amaral-Zettler, L. (2020). Successional blooms of alkenone‐producing haptophytes in Lake George, North Dakota: Implications for continental paleoclimate reconstructions. Limnol. Oceanogr. 65(2): 413-425. https://dx.doi.org/10.1002/lno.11311 In: Limnology and Oceanography. American Society of Limnology and Oceanography: Waco, Tex., etc. ISSN 0024-3590; e-ISSN 1939-5590, more |   |
| Authors | | Top | - Theroux, S.
- Huang, Y.
- Toney, J.L.
| - Andersen, R.
- Nyren, P.
- Bohn, R.
| - Salacup, J.
- Murphy, L.
- Amaral-Zettler, L., more
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| Abstract | Alkenone-derived paleotemperature reconstruction holds great promise in lake environments. However, theoccurrence of multiple species of alkenone-producing haptophyte algae in a single lake can complicate thetranslation of alkenone unsaturation to temperature if each species requires an individual temperature calibra-tion. Here, we present thefirst systematic monitoring of two alkenone-producing haptophytes throughout thecourse of a seasonal cycle in Lake George, North Dakota, using a combined approach of DNA sequencing andalkenone lipid characterization. Field sampling revealed a nonoverlapping haptophyte succession, with both anearly and late season haptophyte bloom event. Culturing experiments demonstrated that the two haptophytespecies responsible for these blooms had statistically similar alkenone-temperature responses, although theculture-based calibrations were distinct from the in situ calibration. Bloom timing of each haptophyte speciescorresponded to surface-water temperatures that differed by more than 10?C, revealing that changes in bloomintensities for each species will skew the sediment-inferred temperatures to a different stage of the growth sea-son. These results highlight the importance of accounting for bloom timing when interpreting alkenone-derivedtemperatures in sediment cores, especially in lakes that experience large seasonalfluctuations in water columntemperature and salinity. |
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