Temporal variation in macrobenthic diet as inferred from fatty acid biomarkers
Braeckman, U.; Provoost, P.; Sabbe, K.; Middelburg, J.J.; Soetaert, K.; Vincx, M.; Vanaverbeke, J. (2011). Temporal variation in macrobenthic diet as inferred from fatty acid biomarkers, in: Braeckman, U. Macrobenthos structuring the sea floor: importance of its functional biodiversity for the benthic ecosystem = De structurerende rol van macrobenthos in de zeebodem: belang van de functionele biodiversiteit voor het benthische ecosysteem. pp. 103-130 In: Braeckman, U. (2011). Macrobenthos structuring the sea floor: importance of its functional biodiversity for the benthic ecosystem = De structurerende rol van macrobenthos in de zeebodem: belang van de functionele biodiversiteit voor het benthische ecosysteem. PhD Thesis. Marine Biology Research Group: Gent. ISBN 9789490695590. 239 pp., more |
| Keywords | Algal blooms
Aquatic communities > Benthos
Aquatic communities > Plankton > Phytoplankton
Biomarkers
Chemical compounds > Organic compounds > Lipids
Isotopes
Lanice conchilega (Pallas, 1766) [WoRMS]; Nephtys hombergii Savigny in Lamarck, 1818 [WoRMS]
Marine/Coastal |
| Abstract | We investigated the temporal variation of pelagic and benthic food sources in the diet of two marine polychaetes: a macrobenthic omnivore (Nephtys hombergii) and a suspension-deposit feeder (Lanice conchilega) by means of fatty acid (FA) biomarkers and compound-specific stable isotope analysis (CSIA). FA biomarkers in the suspended particulate matter mirrored phytoplankton dynamics in the water column, consisting of a small diatom dominance early spring, succeeded by a mass Phaeocystis peak followed by a mixed diatom-dinoflagellate bloom. Deposition and subsequent bacterial degradation of the phytoplankton bloom were reflected in sediment FA biomarkers. The main distinction in FA biomarker concentration within macrobenthic tissue was observed at the species level (50% of variation), the diet of L. conchilega consisting of bacteria and diatoms and that of N. hombergii also of diatoms, but including more dinoflagellates and invertebrates. Temporal variation explained almost 20%: the two species retained more bacterial and Phaeocystis markers before the bloom, while they accumulated more polyunsaturated FA after the bloom. CSIA revealed increased accumulation or biosynthesis of poly-unsaturated FA from the suspended matter in L. conchilega upon bloom deposition, which is probably related to energy storage for gametogenesis. In contrast, bloom–dependent accumulation or biosynthesis of FA was not detected in N. hombergii |
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