Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes
Abstract Large‐scale ecosystem disturbances can alter the flow of energy through food webs, but such processes are not well defined for Gulf of Mexico saltmarsh ecosystems vulnerable to multiple interacting stressors. The 2010 Deepwater Horizon (DWH) oil spill significantly affected the composition...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2017-07-01
|
| Series: | Ecosphere |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ecs2.1878 |
| _version_ | 1811167122611503104 |
|---|---|
| author | Jill A. Olin Christine M. Bergeon Burns Stefan Woltmann Sabrina S. Taylor Philip C. Stouffer Wokil Bam Linda Hooper‐Bui R. Eugene Turner |
| author_facet | Jill A. Olin Christine M. Bergeon Burns Stefan Woltmann Sabrina S. Taylor Philip C. Stouffer Wokil Bam Linda Hooper‐Bui R. Eugene Turner |
| author_sort | Jill A. Olin |
| collection | DOAJ |
| description | Abstract Large‐scale ecosystem disturbances can alter the flow of energy through food webs, but such processes are not well defined for Gulf of Mexico saltmarsh ecosystems vulnerable to multiple interacting stressors. The 2010 Deepwater Horizon (DWH) oil spill significantly affected the composition of terrestrial saltmarsh communities in Louisiana, and thus had the potential to alter energy pathways through terrestrial and aquatic food webs, with direct consequences for higher trophic‐level species restricted to these habitats. The Seaside Sparrow (Ammodramus maritimus) is endemic to saltmarshes and relies completely on the habitat and resources they provide; thus, the sparrows can serve as indicators of ecological change in response to disturbances. We analyzed food web pathways for birds residing in oiled and unoiled saltmarshes for the four years following the oil spill by quantifying the bulk carbon and nitrogen stable isotopes and fatty acid profiles of liver tissues, in addition to primary producers (e.g., marsh grasses) and invertebrate consumers representing the major energy resources in these systems. The stable isotope values of primary producers and most invertebrate consumers did not differ between oiled and unoiled sites, suggesting that the energy pathways within the food web were stable in spite of observed declines in these populations following the spill. The tracer profiles of the Seaside Sparrows confirmed that there was a nominal effect of oil on resource use or trophic position (TP). However, we detected significant inter‐annual variation in resource use by these birds; the sparrows occupied a lower TP and exhibited greater assimilation of resources derived from benthic–aquatic relative to terrestrial pathways in 2013 compared to other years. This distinction is likely attributable to the effects of Hurricane Isaac in 2012, whose significant storm surge extensively inundated the saltmarsh landscape. Despite widespread concern for the saltmarsh ecosystem after the DWH event, the significant effects noted at the population level translated into only subtle differences to the flow of energy through this food web. These results demonstrate varying responses to different degrees of landscape‐level disturbance, such as oil and hurricanes, and establish the need to better understand food web dynamics in these saltmarsh ecosystems. |
| first_indexed | 2024-04-10T16:03:47Z |
| format | Article |
| id | doaj.art-817e8820a9be4e02ab7031fc633aa1ca |
| institution | Directory Open Access Journal |
| issn | 2150-8925 |
| language | English |
| last_indexed | 2024-04-10T16:03:47Z |
| publishDate | 2017-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecosphere |
| spelling | doaj.art-817e8820a9be4e02ab7031fc633aa1ca2023-02-10T07:33:12ZengWileyEcosphere2150-89252017-07-0187n/an/a10.1002/ecs2.1878Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshesJill A. Olin0Christine M. Bergeon Burns1Stefan Woltmann2Sabrina S. Taylor3Philip C. Stouffer4Wokil Bam5Linda Hooper‐Bui6R. Eugene Turner7Department of Oceanography and Coastal Sciences Louisiana State University Baton Rouge Louisiana 70803 USASchool of Renewable Natural Resources Louisiana State University AgCenter Baton Rouge Louisiana 70803 USADepartment of Biology and Center of Excellence for Field Biology Austin Peay State University Clarksville Tennessee 37044 USASchool of Renewable Natural Resources Louisiana State University AgCenter Baton Rouge Louisiana 70803 USASchool of Renewable Natural Resources Louisiana State University AgCenter Baton Rouge Louisiana 70803 USADepartment of Oceanography and Coastal Sciences Louisiana State University Baton Rouge Louisiana 70803 USADepartment of Environmental Sciences Louisiana State University Baton Rouge Louisiana 70803 USADepartment of Oceanography and Coastal Sciences Louisiana State University Baton Rouge Louisiana 70803 USAAbstract Large‐scale ecosystem disturbances can alter the flow of energy through food webs, but such processes are not well defined for Gulf of Mexico saltmarsh ecosystems vulnerable to multiple interacting stressors. The 2010 Deepwater Horizon (DWH) oil spill significantly affected the composition of terrestrial saltmarsh communities in Louisiana, and thus had the potential to alter energy pathways through terrestrial and aquatic food webs, with direct consequences for higher trophic‐level species restricted to these habitats. The Seaside Sparrow (Ammodramus maritimus) is endemic to saltmarshes and relies completely on the habitat and resources they provide; thus, the sparrows can serve as indicators of ecological change in response to disturbances. We analyzed food web pathways for birds residing in oiled and unoiled saltmarshes for the four years following the oil spill by quantifying the bulk carbon and nitrogen stable isotopes and fatty acid profiles of liver tissues, in addition to primary producers (e.g., marsh grasses) and invertebrate consumers representing the major energy resources in these systems. The stable isotope values of primary producers and most invertebrate consumers did not differ between oiled and unoiled sites, suggesting that the energy pathways within the food web were stable in spite of observed declines in these populations following the spill. The tracer profiles of the Seaside Sparrows confirmed that there was a nominal effect of oil on resource use or trophic position (TP). However, we detected significant inter‐annual variation in resource use by these birds; the sparrows occupied a lower TP and exhibited greater assimilation of resources derived from benthic–aquatic relative to terrestrial pathways in 2013 compared to other years. This distinction is likely attributable to the effects of Hurricane Isaac in 2012, whose significant storm surge extensively inundated the saltmarsh landscape. Despite widespread concern for the saltmarsh ecosystem after the DWH event, the significant effects noted at the population level translated into only subtle differences to the flow of energy through this food web. These results demonstrate varying responses to different degrees of landscape‐level disturbance, such as oil and hurricanes, and establish the need to better understand food web dynamics in these saltmarsh ecosystems.https://doi.org/10.1002/ecs2.1878Ammodramus maritimusarthropodsDeepwater Horizon oil spillfatty acidshurricanestable isotopes |
| spellingShingle | Jill A. Olin Christine M. Bergeon Burns Stefan Woltmann Sabrina S. Taylor Philip C. Stouffer Wokil Bam Linda Hooper‐Bui R. Eugene Turner Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes Ecosphere Ammodramus maritimus arthropods Deepwater Horizon oil spill fatty acids hurricane stable isotopes |
| title | Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes |
| title_full | Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes |
| title_fullStr | Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes |
| title_full_unstemmed | Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes |
| title_short | Seaside Sparrows reveal contrasting food web responses to large‐scale stressors in coastal Louisiana saltmarshes |
| title_sort | seaside sparrows reveal contrasting food web responses to large scale stressors in coastal louisiana saltmarshes |
| topic | Ammodramus maritimus arthropods Deepwater Horizon oil spill fatty acids hurricane stable isotopes |
| url | https://doi.org/10.1002/ecs2.1878 |
| work_keys_str_mv | AT jillaolin seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT christinembergeonburns seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT stefanwoltmann seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT sabrinastaylor seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT philipcstouffer seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT wokilbam seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT lindahooperbui seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes AT reugeneturner seasidesparrowsrevealcontrastingfoodwebresponsestolargescalestressorsincoastallouisianasaltmarshes |