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Veenhof RJ, Coleman MA, Champion C, Dworjanyn SA. Urchin grazing of kelp gametophytes in warming oceans. J Phycol 2023; 59:838-855. [PMID: 37432133 DOI: 10.1111/jpy.13364] [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] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 07/12/2023]
Abstract
Sea urchins can cause extensive damage to kelp forests, and their overgrazing can create extensive barren areas, leading to a loss of biodiversity. Barrens may persist when the recruitment of kelp, which occurs through the microscopic haploid gametophyte stage, is suppressed. However, the ecology of kelp gametophytes is poorly understood, and here we investigate if grazing by juvenile urchins on kelp gametophytes can suppress kelp recruitment and if this is exacerbated by climate change. We compared grazing of Ecklonia radiata gametophytes by two species of juvenile urchins, the tropical Tripneustes gratilla and the temperate Centrostephanus rodgersii, at winter (19°C), summer (23°C), and ocean warming (26°C) temperatures for the low-latitude range edge of E. radiata, which is vulnerable to ocean warming. We examined the rate of recovery of gametophytes following grazing and determined whether they survived and formed sporophytes after ingestion by sea urchins. Both T. gratilla and C. rodgersii grazed E. radiata gametophytes, reducing their abundance compared to no grazing controls. Surprisingly, temperature did not influence grazing rates, but gametophytes did not recover from grazing in the ocean warming (26°C) treatment. Gametophytes survived ingestion by both species of sea urchin and formed sporophytes after ingestion by T. gratilla, but not C. rodgersii. These results suggest complex grazer-gametophyte interactions, in which both negative (reduced abundance and poor recovery with warming) and positive (facilitated recruitment) effects are possible. Small grazers may play a more important role in kelp ecosystem function than previously thought and should be considered in our understanding of alternate stable states.
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Affiliation(s)
- Reina J Veenhof
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Melinda A Coleman
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
- NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, New South Wales, Australia
| | - Curtis Champion
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
- NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, New South Wales, Australia
| | - Symon A Dworjanyn
- National Marine Science Centre, Faculty of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
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Strzepek RF, Nunn BL, Bach LT, Berges JA, Young EB, Boyd PW. The ongoing need for rates: can physiology and omics come together to co-design the measurements needed to understand complex ocean biogeochemistry? J Plankton Res 2022; 44:485-495. [PMID: 35898813 PMCID: PMC9310281 DOI: 10.1093/plankt/fbac026] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/05/2022] [Indexed: 05/16/2023]
Abstract
The necessity to understand the influence of global ocean change on biota has exposed wide-ranging gaps in our knowledge of the fundamental principles that underpin marine life. Concurrently, physiological research has stagnated, in part driven by the advent and rapid evolution of molecular biological techniques, such that they now influence all lines of enquiry in biological oceanography. This dominance has led to an implicit assumption that physiology is outmoded, and advocacy that ecological and biogeochemical models can be directly informed by omics. However, the main modeling currencies are biological rates and biogeochemical fluxes. Here, we ask: how do we translate the wealth of information on physiological potential from omics-based studies to quantifiable physiological rates and, ultimately, to biogeochemical fluxes? Based on the trajectory of the state-of-the-art in biomedical sciences, along with case-studies from ocean sciences, we conclude that it is unlikely that omics can provide such rates in the coming decade. Thus, while physiological rates will continue to be central to providing projections of global change biology, we must revisit the metrics we rely upon. We advocate for the co-design of a new generation of rate measurements that better link the benefits of omics and physiology.
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Affiliation(s)
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Foege Building S113 3720 15th Ave NE, Seattle, WA 98195, USA
| | - Lennart T Bach
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia
| | - John A Berges
- Department of Biological Sciences and School of Freshwater Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, WI 53211, USA
| | - Erica B Young
- Department of Biological Sciences and School of Freshwater Sciences, University of Wisconsin-Milwaukee, 3209 N. Maryland Avenue, Milwaukee, WI 53211, USA
| | - Philip W Boyd
- Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, TAS 7004, Australia
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia
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Miloslavich P, Bax NJ, Simmons SE, Klein E, Appeltans W, Aburto-Oropeza O, Andersen Garcia M, Batten SD, Benedetti-Cecchi L, Checkley DM, Chiba S, Duffy JE, Dunn DC, Fischer A, Gunn J, Kudela R, Marsac F, Muller-Karger FE, Obura D, Shin YJ. Essential ocean variables for global sustained observations of biodiversity and ecosystem changes. Glob Chang Biol 2018; 24:2416-2433. [PMID: 29623683 DOI: 10.1111/gcb.14108] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 05/21/2023]
Abstract
Sustained observations of marine biodiversity and ecosystems focused on specific conservation and management problems are needed around the world to effectively mitigate or manage changes resulting from anthropogenic pressures. These observations, while complex and expensive, are required by the international scientific, governance and policy communities to provide baselines against which the effects of human pressures and climate change may be measured and reported, and resources allocated to implement solutions. To identify biological and ecological essential ocean variables (EOVs) for implementation within a global ocean observing system that is relevant for science, informs society, and technologically feasible, we used a driver-pressure-state-impact-response (DPSIR) model. We (1) examined relevant international agreements to identify societal drivers and pressures on marine resources and ecosystems, (2) evaluated the temporal and spatial scales of variables measured by 100+ observing programs, and (3) analysed the impact and scalability of these variables and how they contribute to address societal and scientific issues. EOVs were related to the status of ecosystem components (phytoplankton and zooplankton biomass and diversity, and abundance and distribution of fish, marine turtles, birds and mammals), and to the extent and health of ecosystems (cover and composition of hard coral, seagrass, mangrove and macroalgal canopy). Benthic invertebrate abundance and distribution and microbe diversity and biomass were identified as emerging EOVs to be developed based on emerging requirements and new technologies. The temporal scale at which any shifts in biological systems will be detected will vary across the EOVs, the properties being monitored and the length of the existing time-series. Global implementation to deliver useful products will require collaboration of the scientific and policy sectors and a significant commitment to improve human and infrastructure capacity across the globe, including the development of new, more automated observing technologies, and encouraging the application of international standards and best practices.
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Affiliation(s)
- Patricia Miloslavich
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
- Departamento de Estudios Ambientales, Universidad Simón Bolívar, Caracas, Venezuela
- Australian Institute of Marine Science, Townsville, Qld, Australia
- Oceans Institute, University of Western Australia, Crawley, WA, Australia
| | - Nicholas J Bax
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
- CSIRO, Oceans and Atmosphere, Hobart, Tas., Australia
| | | | - Eduardo Klein
- Departamento de Estudios Ambientales, Universidad Simón Bolívar, Caracas, Venezuela
| | - Ward Appeltans
- Intergovernmental Oceanographic Commission of UNESCO, IOC Project Office for IODE, Oostende, Belgium
| | - Octavio Aburto-Oropeza
- Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA, USA
| | - Melissa Andersen Garcia
- National Oceanic and Atmospheric Administration (NOAA), Office of International Affairs, Washington, DC, USA
| | - Sonia D Batten
- Sir Alister Hardy Foundation for Ocean Science (SAHFOS), Nanaimo, BC, Canada
| | | | | | - Sanae Chiba
- UN Environment-World Conservation Monitoring Centre, Cambridge, UK
- Research and Development Center for Global Change (RCGC), JAMSTEC, Yokohama, Japan
| | - J Emmett Duffy
- Tennenbaum Marine Observatories Network, Smithsonian Institution, Edgewater, MD, USA
| | - Daniel C Dunn
- Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Beaufort, NC, USA
| | - Albert Fischer
- Intergovermental Oceanographic Commission IOC/UNESCO, Paris, France
| | - John Gunn
- Australian Institute of Marine Science, Townsville, Qld, Australia
| | - Raphael Kudela
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Francis Marsac
- Institut de Recherche pour le Développement (IRD), UMR MARBEC 248, Université Montpellier, Montpellier, France
- Department of Oceanography, University of Cape Town, Rondebosch, South Africa
| | - Frank E Muller-Karger
- Institute for Marine Remote Sensing/IMaRS, College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | | | - Yunne-Jai Shin
- Institut de Recherche pour le Développement (IRD), UMR MARBEC 248, Université Montpellier, Montpellier, France
- Department of Biological Sciences, Ma-Re Institute, University of Cape Town, Rondebosch, South Africa
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