1
|
Olmstead ARB, Mathieson OL, McLellan WA, Pabst DA, Keenan TF, Goldstein T, Erwin PM. Gut bacterial communities in Atlantic bottlenose dolphins (Tursiops truncatus) throughout a disease-driven (Morbillivirus) unusual mortality event. FEMS Microbiol Ecol 2023; 99:fiad097. [PMID: 37591660 DOI: 10.1093/femsec/fiad097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 08/19/2023] Open
Abstract
Gut microbiomes are important determinants of animal health. In sentinel marine mammals where animal and ocean health are connected, microbiome impacts can scale to ecosystem-level importance. Mass mortality events affect cetacean populations worldwide, yet little is known about the contributory role of their gut bacterial communities to disease susceptibility and progression. Here, we characterized bacterial communities from fecal samples of common bottlenose dolphins, Tursiops truncatus, across an unusual mortality event (UME) caused by dolphin Morbillivirus (DMV). 16S rRNA gene sequence analysis revealed similar diversity and structure of bacterial communities in individuals stranding before, during, and after the 2013-2015 Mid-Atlantic Bottlenose Dolphin UME and these trends held in a subset of dolphins tested by PCR for DMV infection. Fine-scale shifts related to the UME were not common (10 of 968 bacterial taxa) though potential biomarkers for health monitoring were identified within the complex bacterial communities. Accordingly, acute DMV infection was not associated with a distinct gut bacterial community signature in T. truncatus. However, temporal stratification of DMV-positive dolphins did reveal changes in bacterial community composition between early and late outbreak periods, suggesting that gut community disruptions may be amplified by the indirect effects of accumulating health burdens associated with chronic morbidity.
Collapse
Affiliation(s)
- Alyssa R B Olmstead
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| | - Olivia L Mathieson
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| | - William A McLellan
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| | - D Ann Pabst
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| | - Tiffany F Keenan
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| | - Tracey Goldstein
- Zoological Pathology Program, University of Illinois at Urbana-Champaign, 3300 Golf Road, Brookfield, IL 60513, United States
| | - Patrick M Erwin
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, United States
| |
Collapse
|
2
|
Keenan TF, Luo X, De Kauwe MG, Medlyn BE, Prentice IC, Stocker BD, Smith NG, Terrer C, Wang H, Zhang Y, Zhou S. A constraint on historic growth in global photosynthesis due to increasing CO 2. Nature 2021; 600:253-258. [PMID: 34880429 DOI: 10.1038/s41586-021-04096-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/05/2021] [Indexed: 11/09/2022]
Abstract
The global terrestrial carbon sink is increasing1-3, offsetting roughly a third of anthropogenic CO2 released into the atmosphere each decade1, and thus serving to slow4 the growth of atmospheric CO2. It has been suggested that a CO2-induced long-term increase in global photosynthesis, a process known as CO2 fertilization, is responsible for a large proportion of the current terrestrial carbon sink4-7. The estimated magnitude of the historic increase in photosynthesis as result of increasing atmospheric CO2 concentrations, however, differs by an order of magnitude between long-term proxies and terrestrial biosphere models7-13. Here we quantify the historic effect of CO2 on global photosynthesis by identifying an emergent constraint14-16 that combines terrestrial biosphere models with global carbon budget estimates. Our analysis suggests that CO2 fertilization increased global annual photosynthesis by 11.85 ± 1.4%, or 13.98 ± 1.63 petagrams carbon (mean ± 95% confidence interval) between 1981 and 2020. Our results help resolve conflicting estimates of the historic sensitivity of global photosynthesis to CO2, and highlight the large impact anthropogenic emissions have had on ecosystems worldwide.
Collapse
Affiliation(s)
- T F Keenan
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, USA. .,Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - X Luo
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, USA.,Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Department of Geography, National University of, Singapore, Singapore
| | - M G De Kauwe
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia.,Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia.,School of Biological Sciences, University of Bristol, Bristol, UK
| | - B E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - I C Prentice
- Department of Life Sciences, Imperial College London, Ascot, UK.,Department of Biological Sciences, Macquarie University, North Ryde, New South Wales, Australia.,Department of Earth System Science, Tsinghua University, Haidian, Beijing, China
| | - B D Stocker
- Department of Environmental Systems Science, ETH, Zurich, Switzerland.,Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - N G Smith
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - C Terrer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Boston, MA, USA
| | - H Wang
- Department of Earth System Science, Tsinghua University, Haidian, Beijing, China
| | - Y Zhang
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, USA.,Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - S Zhou
- Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, USA.,Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA.,Earth Institute, Columbia University, New York, NY, USA.,Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA.,State Key Laboratory of Earth Surface Processes and Resources Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China
| |
Collapse
|
3
|
Keenan TF, McLellan WA, Rommel SA, Costidis AM, Harms CA, Thewissen 'HJ, Rotstein DS, Gay MD, Potter CW, Taylor AR, Wang Y, Pabst DA. Gross and histological morphology of the cervical gill slit gland of the pygmy sperm whale (Kogia breviceps). Anat Rec (Hoboken) 2021; 305:688-703. [PMID: 34288509 DOI: 10.1002/ar.24707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/14/2021] [Indexed: 11/11/2022]
Abstract
Odontocete cetaceans have undergone profound modifications to their integument and sensory systems and are generally thought to lack specialized exocrine glands that in terrestrial mammals function to produce chemical signals (Thewissen & Nummela, 2008). Keenan-Bateman et al. (2016, 2018), though, introduced an enigmatic exocrine gland, associated with the false gill slit pigmentation pattern in Kogia breviceps. These authors provided a preliminary description of this cervical gill slit gland in their helminthological studies of the parasitic nematode, Crassicauda magna. This study offers the first detailed gross and histological description of this gland and reports upon key differences between immature and mature individuals. Investigation reveals it is a complex, compound tubuloalveolar gland with a well-defined duct that leads to a large, and expandable central chamber, which in turn leads to two caudally projecting diverticula. All regions of the gland contain branched tubular and alveolar secretory regions, although most are found in the caudal diverticula, where the secretory process is holocrine. The gland lies between slips of cutaneous muscle, and is innervated by lamellar corpuscles, resembling Pacinian's corpuscles, suggesting that its secretory product may be actively expressed into the environment. Mature K. breviceps display larger gland size, and increased functional activity in glandular tissues, as compared to immature individuals. These results demonstrate that the cervical gill slit gland of K. breviceps shares morphological features of the specialized, chemical signaling, exocrine glands of terrestrial members of the Cetartiodactyla.
Collapse
Affiliation(s)
- Tiffany F Keenan
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina
| | - William A McLellan
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina
| | - Sentiel A Rommel
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina
| | | | - Craig A Harms
- Center for Marine Sciences and Technology, North Carolina State University, Morehead City, North Carolina
| | - 'Hans' Jgm Thewissen
- Department of Anatomy/Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio
| | | | - Mark D Gay
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina
| | - Charles W Potter
- Department of Vertebrate Zoology, Smithsonian Institution, National Museum of Natural History, Washington, District of Columbia, USA
| | - Alison R Taylor
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina
| | - Ying Wang
- University of North Carolina Wilmington, Department of Chemistry and Biochemistry, Wilmington, North Carolina
| | - D Ann Pabst
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina
| |
Collapse
|
4
|
Keenan TF, Darby B, Felts E, Sonnentag O, Friedl MA, Hufkens K, O'Keef J, Klosterman S, Munger JW, Toome M, Richardson AD. Tracking forest phenology and seasonal physiology using digital repeat photography: a critical assessment. Ecol Appl 2014; 24:1478-89. [PMID: 29160668 DOI: 10.1890/13-0652.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Digital repeat photography is becoming widely used for near-surface remote sensing of vegetation. Canopy greenness, which has been used extensively for phenological applications, can be readily quantified from camera images. Important questions remain, however, as to whether the observed changes in canopy greenness are directly related to changes in leaf-level traits, changes in canopy structure, or some combination thereof. We investigated relationships between canopy greenness and various metrics of canopy structure and function, using five years (2008–2012) of automated digital imagery, ground observations of phenological transitions, leaf area index (LAI) measurements, and eddy covariance estimates of gross ecosystem photosynthesis from the Harvard Forest, a temperate deciduous forest in the northeastern United States. Additionally, we sampled canopy sunlit leaves on a weekly basis throughout the growing season of 2011. We measured physiological and morphological traits including leaf size, mass (wet/dry), nitrogen content, chlorophyll fluorescence, and spectral reflectance and characterized individual leaf color with flatbed scanner imagery. Our results show that observed spring and autumn phenological transition dates are well captured by information extracted from digital repeat photography. However, spring development of both LAI and the measured physiological and morphological traits are shown to lag behind spring increases in canopy greenness, which rises very quickly to its maximum value before leaves are even half their final size. Based on the hypothesis that changes in canopy greenness represent the aggregate effect of changes in both leaf-level properties (specifically, leaf color) and changes in canopy structure (specifically, LAI), we developed a two end-member mixing model. With just a single free parameter, the model was able to reproduce the observed seasonal trajectory of canopy greenness. This analysis shows that canopy greenness is relatively insensitive to changes in LAI at high LAI levels, which we further demonstrate by assessing the impact of an ice storm on both LAI and canopy greenness. Our study provides new insights into the mechanisms driving seasonal changes in canopy greenness retrieved from digital camera imagery. The nonlinear relationship between canopy greenness and canopy LAI has important implications both for phenological research applications and for assessing responses of vegetation to disturbances.
Collapse
|