Fish predators maintain estuarine biodiversity and benefit ecosystem engineers
| dc.contributor.advisor | Smee, Delbert Lee | |
| dc.contributor.advisor | Walther, Benjamin D. | |
| dc.contributor.author | Reustle, Joseph William Newton Leo | |
| dc.contributor.committeeMember | Turner, Jeffrey W. | |
| dc.contributor.committeeMember | Conkle, Jeremy L. | |
| dc.contributor.committeeMember | Bogucki, Darek J. | |
| dc.creator.orcid | https://orcid.org/0000-0001-7307-9993 | |
| dc.creator.orcid | 0000-0001-7307-9993 | en_US |
| dc.date.accessioned | 2020-11-08T17:09:54Z | |
| dc.date.available | 2020-11-08T17:09:54Z | |
| dc.date.issued | 2020-05 | |
| dc.description.abstract | Loss of top predators may lead to the proliferation of mesopredators (i.e., intermediate consumers), with significant consequences for entire food webs. Termed mesopredator release, this process is typically attributed to a decline in the abundance of top predators. We investigated the potential for moderate environmental changes, that disrupt sensing abilities, to trigger mesopredator release by diminishing the foraging ability of top predators without affecting their abundance. In estuaries, fishes occupy the upper trophic levels and many species rely on visual cues to forage. We hypothesized that increased turbidity would attenuate fish foraging ability, increase the abundance of crabs and other mesopredators, and significantly alter coastal food webs. In oyster reef communities, turbidity triggered mesopredator release in 2016 and 2017, even though freshwater inflow and ambient salinity varied significantly between years, suggesting that turbidity’s effects on estuarine food webs are robust. Following experiments in 2017, our field site was struck by Hurricane Harvey, a category 4 storm. Oyster mortality was high following Harvey due to low salinity and trophic reliance on oysters as a basal resource. Hurricane Harvey removed human fishing pressure, causing fish populations to increase dramatically, resulting in stronger top-down control on crabs that are the primary predator of newly settled oysters. We also investigated the potential for barnacles as accessible and biologically relevant flow indicators since hydrodynamics are key regulators of speciesinteractions. In summary, fish predators are important components of oyster reef ecosystems, enhancing biodiversity and, at times, benefiting oysters through a trophic cascade depending on the environmental context. Turbidity and fishing reduce top down control by fishes, leading to increases in the abundance of intermediate consumers, less diverse reef communities, and often damaging juvenile oysters. | en_US |
| dc.description.college | College of Science and Engineering | en_US |
| dc.description.department | Life Sciences | en_US |
| dc.format.extent | 168 pages | en_US |
| dc.identifier.uri | https://hdl.handle.net/1969.6/89109 | |
| dc.language.iso | en_US | en_US |
| dc.rights | Attribution 4.0 International | * |
| dc.rights | This material is made available for use in research, teaching, and private study, pursuant to U.S. Copyright law. The user assumes full responsibility for any use of the materials, including but not limited to, infringement of copyright and publication rights of reproduced materials. Any materials used should be fully credited with its source. All rights are reserved and retained regardless of current or future development or laws that may apply to fair use standards. Permission for publication of this material, in part or in full, must be secured with the author and/or publisher. | en_US |
| dc.rights.holder | Reustle, Joseph William Newton Leo | |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | * |
| dc.subject | mesopredator | en_US |
| dc.subject | oyster reefs | en_US |
| dc.subject | phenotypic plasticity | en_US |
| dc.subject | salinity | en_US |
| dc.subject | top-down | en_US |
| dc.subject | turbidity | en_US |
| dc.subject.lcsh | ecology | en_US |
| dc.subject.lcsh | aquatic sciences | en_US |
| dc.title | Fish predators maintain estuarine biodiversity and benefit ecosystem engineers | en_US |
| dc.type | Text | en_US |
| dc.type.genre | Dissertation | en_US |
| dcterms.type | Text | |
| thesis.degree.discipline | Marine Biology | en_US |
| thesis.degree.grantor | Texas A & M University--Corpus Christi | en_US |
| thesis.degree.level | Doctoral | en_US |
| thesis.degree.name | Doctor of Philosophy | en_US |