Does reef structure affect oyster food resources? A stable isotope assessment.
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 (δ13C, δ15N) 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 in13C (-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.
Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, TX 78412-5869, USA. Electronic address: bblomberg@disl.org.
Brittany N
BN
Blomberg
Institut du Littoral et de l'Environnement, Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France. Electronic address: benoit.lebreton@univ-lr.fr.
Benoit
B
Lebreton
Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, TX 78412-5869, USA. Electronic address: terry.palmer@tamucc.edu.
Terence A
TA
Palmer
Institut du Littoral et de l'Environnement, Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France. Electronic address: gguill01@univ-lr.fr.
Gaël
G
Guillou
Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX 78412-5800, USA. Electronic address: Jennifer.pollack@tamucc.edu.
Jennifer
J
Beseres Pollack
Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, TX 78412-5869, USA. Electronic address: paul.montagna@tamucc.edu.
Paul A
PA
Montagna
D000818:Animals; D018533:Biomass; D002247:Carbon Isotopes / Q000032:analysis; D017753:Ecosystem; D004784:Environmental Monitoring; D020387:Food Chain; D009587:Nitrogen Isotopes / Q000032:analysis; D010125:Ostreidae / Q000502:physiology*; D010839:Phytoplankton; D011157:Population Dynamics
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes
Bentho-pelagic coupling; Food source; Gulf of Mexico; Oyster reef; Sediment organic matter; Stable isotopes; Suspended particulate organic matter