1
|
Raoult V, Phillips AA, Nelson J, Niella Y, Skinner C, Tilcock MB, Burke PJ, Szpak P, James WR, Harrod C. Why aquatic scientists should use sulfur stable isotope ratios (ẟ 34S) more often. CHEMOSPHERE 2024; 355:141816. [PMID: 38556184 DOI: 10.1016/j.chemosphere.2024.141816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 02/26/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
Over the last few decades, measurements of light stable isotope ratios have been increasingly used to answer questions across physiology, biology, ecology, and archaeology. The vast majority analyse carbon (δ13C) and nitrogen (δ15N) stable isotopes as the 'default' isotopes, omitting sulfur (δ34S) due to time, cost, or perceived lack of benefits and instrumentation capabilities. Using just carbon and nitrogen isotopic ratios can produce results that are inconclusive, uncertain, or in the worst cases, even misleading, especially for scientists that are new to the use and interpretation of stable isotope data. Using sulfur isotope values more regularly has the potential to mitigate these issues, especially given recent advancements that have lowered measurement barriers. Here we provide a review documenting case studies with real-world data, re-analysing different biological topics (i.e. niche, physiology, diet, movement and bioarchaeology) with and without sulfur isotopes to highlight the various strengths of this stable isotope for various applications. We also include a preliminary meta-analysis of the trophic discrimination factor (TDF) for sulfur isotopes, which suggest small (mean -0.4 ± 1.7 ‰ SD) but taxa-dependent mean trophic discrimination. Each case study demonstrates how the exclusion of sulfur comes at the detriment of the results, often leading to very different outputs, or missing valuable discoveries entirely. Given that studies relying on carbon and nitrogen stable isotopes currently underpin most of our understanding of various ecological processes, this has concerning implications. Collectively, these examples strongly suggest that researchers planning to use carbon and nitrogen stable isotopes for their research should incorporate sulfur where possible, and that the new 'default' isotope systems for aquatic science should now be carbon, nitrogen, and sulfur.
Collapse
Affiliation(s)
- Vincent Raoult
- Blue Carbon Lab, School of Life and Environmental Science, Deakin University, VIC, Australia; Marine Ecology Group, School of Natural Sciences, Macquarie University, NSW, Australia.
| | - Alexandra A Phillips
- National Center for Ecological Analysis and Synthesis, University of California Santa Barbara, Santa Barbara, CA, USA
| | - James Nelson
- Department of Marine Science, University of Georgia, Athens, GA, USA
| | - Yuri Niella
- Marine Ecology Group, School of Natural Sciences, Macquarie University, NSW, Australia
| | - Christina Skinner
- Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, QLD, Australia
| | | | - Patrick J Burke
- Marine Ecology Group, School of Natural Sciences, Macquarie University, NSW, Australia
| | - Paul Szpak
- Department of Anthropology, Trent University, Peterborough, Ontario, Canada
| | - W Ryan James
- Institute of Environment, Florida International University, Miami, FL, USA
| | - Chris Harrod
- Instituto Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Antofagasta, Chile; Millennium Nucleus INVASAL, Concepción, Chile; Universidad de Antofagasta Stable Isotope Facility, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| |
Collapse
|
2
|
Eglite E, Mohm C, Dierking J. Stable isotope analysis in food web research: Systematic review and a vision for the future for the Baltic Sea macro-region. AMBIO 2023; 52:319-338. [PMID: 36269552 PMCID: PMC9589642 DOI: 10.1007/s13280-022-01785-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 06/01/2022] [Accepted: 08/08/2022] [Indexed: 06/16/2023]
Abstract
Food web research provides essential insights into ecosystem functioning, but practical applications in ecosystem-based management are hampered by a current lack of knowledge synthesis. To address this gap, we provide the first systematic review of ecological studies applying stable isotope analysis, a pivotal method in food web research, in the heavily anthropogenically impacted Baltic Sea macro-region. We identified a thriving research field, with 164 publications advancing a broad range of fundamental and applied research topics, but also found structural shortcomings limiting ecosystem-level understanding. We argue that enhanced collaboration and integration, including the systematic submission of Baltic Sea primary datasets to stable isotope databases, would help to overcome many of the current shortcomings, unify the scattered knowledge base, and promote future food web research and science-based resource management. The effort undertaken here demonstrates the value of macro-regional synthesis, in enhancing access to existing data and supporting strategic planning of research agendas.
Collapse
Affiliation(s)
- Elvita Eglite
- Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907 USA
| | - Clarissa Mohm
- Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Jan Dierking
- Marine Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany
| |
Collapse
|
3
|
Riekenberg PM, van der Heide T, Holthuijsen SJ, van der Veer HW, van der Meer MTJ. Compound-specific stable isotope analysis of amino acid nitrogen reveals detrital support of microphytobenthos in the Dutch Wadden Sea benthic food web. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.951047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Wadden Sea is the world’s largest intertidal ecosystem and provides vital food resources for a large number of migratory bird and fish species during seasonal stopovers. Previous work using bulk stable isotope analysis of carbon found that microphytobenthos (MPB) was the dominant resource fueling the food web with particulate organic matter making up the remainder. However, this work was unable to account for the trophic structure of the food web or the considerable increase in δ15N values of bulk tissue throughout the benthic food web occurring in the Eastern regions of the Dutch Wadden Sea. Here, we combine compound-specific and bulk analytical stable isotope techniques to further resolve the trophic structure and resource use throughout the benthic food web in the Wadden Sea. Analysis of δ15N for trophic and source amino acids allowed for better identification of trophic relationships due to the integration of underlying variation in the nitrogen resources supporting the food web. Baseline-integrated trophic position estimates using glutamic acid (Glu) and phenylalanine (Phe) allow for disentanglement of baseline variations in underlying δ15N sources supporting the ecosystem and trophic shifts resulting from changes in ecological relationships. Through this application, we further confirmed the dominant ecosystem support by MPB-derived resources, although to a lesser extent than previously estimated. In addition to phytoplankton-derived particulate, organic matter and MPB supported from nutrients from the overlying water column there appears to be an additional resource supporting the benthic community. From the stable isotope mixing models, a subset of species appears to focus on MPB supported off recycled (porewater) N and/or detrital organic matter mainly driven by increased phenylalanine δ15N values. This additional resource within MPB may play a role in subsidizing the exceptional benthic productivity observed within the Wadden Sea ecosystem and reflect division in MPB support along green (herbivory) and brown (recycled/detrital) food web pathways.
Collapse
|
4
|
Food Sources for Benthic Grazers in Trophic Networks of Macrophyte Habitats in a Transitional Baltic Ecosystem. WATER 2022. [DOI: 10.3390/w14101565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In this study, we provide insights into that characteristics of two sites representing different conditions of productivity and salinity impact on trophic network structures of macrophyte habitats and diet of benthic grazers at the active vegetation period in the Curonian Lagoon (southeastern Baltic Sea). Regarding the epiphytic growth, macrophytes were more overgrown in the relatively less productive (northern) site with a muddy bottom and more frequent marine water inflow than in the (southern) site with higher productivity and freshwater sandy habitat. Stable isotope analysis revealed that organisms’ samples from the northern site were more enriched with the heavier carbon isotopes, but depleted in the heavier nitrogen isotopes than those from the southern site. Gastropods and amphipods mainly consumed sedimentary organic matter in the southern site, while they grazed epiphytes together with sedimentary organic matter in the northern site. Although to a low extent, gastropods consumed more charophytes than pondweeds in the southern site. This study contributes to a better understanding of the functioning and structure of lagoonal systems, highlighting the importance, often overlooked, of the benthic compartment, which, however, may have a relevant influence on the productivity of the whole system.
Collapse
|
5
|
Kahma TI, Karlson AML, Liénart C, Mörth CM, Humborg C, Norkko A, Rodil IF. Food-web comparisons between two shallow vegetated habitat types in the Baltic Sea. MARINE ENVIRONMENTAL RESEARCH 2021; 169:105402. [PMID: 34246890 DOI: 10.1016/j.marenvres.2021.105402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Coastal vegetated habitats maintain highly diverse communities, where the contribution of macrophyte production is significant for macroinvertebrate primary consumers. In the brackish-waters of the Baltic Sea, the taxonomical diversity of different macrophytes includes both marine and limnic species. To study the basal food-web differences of two key vegetated habitat types, either dominated by a perennial brown macroalgae (Fucus vesiculosus) or by angiosperm plants, 13C and 15N compositions of different primary producers and macroinvertebrate consumers were examined, and their diets were estimated by Bayesian mixing models. Carbon isotope diversity of primary producers was high especially in the hard-bottom Fucus-dominated habitats, which was also reflected in a larger consumer isotope niche. However, consumer isotope niche among sites was similar within the same habitat type. Our models indicated that the perennial macrophyte dietary median contribution was about 25% for deposit feeders and omnivores in both habitat types, while epigrazers preferred filamentous algae (30-60%). The niche positions of the abundant clams L. balthica, M. arenaria and C. glaucum differed between the two habitats, but they showed only small (<10% units) differences in their macrophyte dietary contributions. The isotopic compositions of the dominating primary producer assemblage reflected significantly in the isotope niche structure of the associated primary consumers.
Collapse
Affiliation(s)
- T I Kahma
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland.
| | - A M L Karlson
- Department of Ecology, Environment and Plant Science, Stockholm University, Stockholm, Sweden; Baltic Sea Centre, Stockholm University, Stockholm, Sweden.
| | - C Liénart
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland; Baltic Sea Centre, Stockholm University, Stockholm, Sweden.
| | - C-M Mörth
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
| | - C Humborg
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland; Baltic Sea Centre, Stockholm University, Stockholm, Sweden.
| | - A Norkko
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland; Baltic Sea Centre, Stockholm University, Stockholm, Sweden.
| | - I F Rodil
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland; Baltic Sea Centre, Stockholm University, Stockholm, Sweden; Departamento de Biología, Instituto Universitario de Investigación Marina (INMAR), University of Cádiz, Spain.
| |
Collapse
|
6
|
Rodríguez MA. Measurement error models reveal the scale of consumer movements along an isoscape gradient. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Marco A. Rodríguez
- Département des sciences de l'environnement and Centre de Recherche sur les Interactions Bassins Versants – Écosystèmes Aquatiques (RIVE) Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada
| |
Collapse
|