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Full-Text Articles in Life Sciences

Using Stable Isotope Analyses To Assess The Trophic Ecology Of Scleractinian Corals, Michael P. Lesser, Marc Slattery, Keir J. Macartney Nov 2022

Using Stable Isotope Analyses To Assess The Trophic Ecology Of Scleractinian Corals, Michael P. Lesser, Marc Slattery, Keir J. Macartney

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Studies on the trophic ecology of scleractinian corals often include stable isotope analyses of tissue and symbiont carbon and nitrogen. These approaches have provided critical insights into the trophic sources and sinks that are essential to understanding larger-scale carbon and nitrogen budgets on coral reefs. While stable isotopes have identified most shallow water (<30 m) corals as mixotrophic, with variable dependencies on autotrophic versus heterotrophic resources, corals in the mesophotic zone (~30–150 m) transition to heterotrophy with increasing depth because of decreased photosynthetic productivity. Recently, these interpretations of the stable isotope data to distinguish between autotrophy and heterotrophy have been criticized because they are confounded by increased nutrients, reverse translocation of photosynthate, and changes in irradiance that do not influence photosynthate translocation. Here we critically examine the studies that support these criticisms and show that they are contextually not relevant to interpreting the transition to heterotrophy in corals from shallow to mesophotic depths. Additionally, new data and a re-analysis of previously published data show that additional information (e.g., skeletal isotopic analysis) improves the interpretation of bulk stable isotope data in determining when a transition from primary dependence on autotrophy to heterotrophy occurs in scleractinian corals.


Investigating Trophic Interactions, Habitat Use, And Pollution Loads Of Bottlenose Dolphins (Tursiops Truncatus) In The Florida Coastal Everglades, Valeria A. Paz Jun 2022

Investigating Trophic Interactions, Habitat Use, And Pollution Loads Of Bottlenose Dolphins (Tursiops Truncatus) In The Florida Coastal Everglades, Valeria A. Paz

FIU Electronic Theses and Dissertations

Cetaceans can feed at upper trophic levels and occur from freshwater to open-ocean ecosystems. Due to their abundance, mobility, and high metabolic rates, they have the potential to affect the structure and function of ecosystems through both top-down and bottom-up pathways. To better understand what ecological roles they may play in a system, it is important to understand patterns and drivers of their abundance, habitat use, and trophic interactions. I investigated the trophic interactions, pollutant exposure, and factors influencing habitat use of common bottlenose dolphins (Tursiops truncatus) of the Florida Coastal Everglades. Based on bulk stable isotope analysis …


Favorable Spring Conditions Can Buffer The Impact Of Winter Carryover Effects On A Key Breeding Decision In An Arctic-Breeding Seabird, Rolanda J. Steenweg, Glenn T. Crossin, Holly L. Hennin, H. Grant Gilchrist, Oliver P. Love Feb 2022

Favorable Spring Conditions Can Buffer The Impact Of Winter Carryover Effects On A Key Breeding Decision In An Arctic-Breeding Seabird, Rolanda J. Steenweg, Glenn T. Crossin, Holly L. Hennin, H. Grant Gilchrist, Oliver P. Love

Great Lakes Institute for Environmental Research Publications

The availability and investment of energy among successive life-history stages is a key feature of carryover effects. In migratory organisms, examining how both winter and spring experiences carryover to affect breeding activity is difficult due to the challenges in tracking individuals through these periods without impacting their behavior, thereby biasing results. Using common eiders Somateria mollissima, we examined whether spring conditions at an Arctic breeding colony (East Bay Island, Nunavut, Canada) can buffer the impacts of winter temperatures on body mass and breeding decisions in birds that winter at different locations (Nuuk and Disko Bay, Greenland, and Newfoundland, Canada; assessed …