Does reef structure affect oyster food resources? A stable isotope assessment. (June 2017)

• Record Type: Journal Article
• Authors: Blomberg, Brittany N.; Lebreton, Benoit; Palmer, Terence A.; Guillou, Gaël; Beseres Pollack, Jennifer; Montagna, Paul A.
• Is Part Of: Marine environmental research. Volume 127(2017)
• Page Start: 32
• Page End: 40
• Publication Date: 2017-06
• Subjects: Food source -- Oyster reef -- Bentho-pelagic coupling -- Stable isotopes -- Suspended particulate organic matter -- Sediment organic matter -- Gulf of Mexico; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2017.03.003
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: As ecosystem engineers, oysters create and maintain structured habitat and can influence trophodynamics and benthic-pelagic coupling in the surrounding landscape. The physical reef structure and associated biotic parameters can affect the availability of food resources for oysters. Oysters and potential composite food sources — suspended particulate organic matter (SPOM) and surface sediment organic matter (SSOM) — were assessed using a dual stable isotope (δ 13 C, δ 15 N) approach at three reef types (natural, restored, and unconsolidated) seasonally for two years to determine if changes in physical and/or biotic parameters affected the relative availability and/or use of food resources by oysters. SPOM was more depleted in 13 C (−24.2 ± 0.6‰, mean ± SD) than SSOM (−21.2 ± 0.8‰). SPOM composition is likely dominated by autochthonous phytoplankton production, while SSOM includes trapped phytoplankton and benthic microalgae. SSOM was used by oysters in increasing proportions relative to SPOM over time at all reef types. This temporal trend is likely due to increased oyster biomass over time, promoting enhanced microphytobenthos growth through feedback effects related to oyster biodeposits. Structural differences between reef types observed in this study had no effect on food resource availability and use by oysters, indicating strong bentho-pelagic coupling likely due to shallow depths as well as strong and consistent winds. This study provides insights for restoration of oyster reefs as it highlights that food resources used by oysters remain similar among reef types despite changes in abiotic and biotic parameters among habitats and over time. Highlights: Food resource availability and use by oysters was examined at three reef types. Water column and sediment food sources were distinguished based on δ 13 C values. Food resource use by oysters was similar among the three reef types. Use of sediment organic matter by oysters increased over time at all reef types. Feedback effects of oysters may influence food resource availability and use.