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Ern R, Jutfelt F. The OptoReg system: a simple and inexpensive solution for regulating water oxygen. CONSERVATION PHYSIOLOGY 2024; 12:coae024. [PMID: 38737128 PMCID: PMC11087874 DOI: 10.1093/conphys/coae024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/20/2024] [Accepted: 04/09/2024] [Indexed: 05/14/2024]
Abstract
This paper describes an optocoupler-based regulation apparatus for saturation manipulation of oxygen in water (OptoReg). This system enables control of solenoid valves for oxygen and nitrogen gases using a FireSting-O2 meter, an optocoupler box and an electronic switch box. The hardware components connect to a computer through Universal Serial Bus (USB) cables. The control software is free and has a graphical user interface, making it easy to use. With the OptoReg system, any lab with a computer running Microsoft Windows operating system and a 4-channel FireSting-O2 meter can easily and cheaply set up four independently controlled systems for regulating water oxygen levels. Here, we describe how to assemble and run the OptoReg system and present a data set demonstrating the high precision and stability of the OptoReg system during static acclimation experiments and dynamic warming trials.
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Affiliation(s)
- Rasmus Ern
- Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7034 Trondheim, Norway
| | - Fredrik Jutfelt
- Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7034 Trondheim, Norway
- Department of Biology and Environmental Sciences, University of Gothenburg, Medicinaregatan 7B, 413 90 Gothenburg, Sweden
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2
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Kumala L, Thomsen M, Canfield DE. Respiration kinetics and allometric scaling in the demosponge Halichondria panicea. BMC Ecol Evol 2023; 23:53. [PMID: 37726687 PMCID: PMC10507823 DOI: 10.1186/s12862-023-02163-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 09/04/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND The aquiferous system in sponges represents one of the simplest circulatory systems used by animals for the internal uptake and distribution of oxygen and metabolic substrates. Its modular organization enables sponges to metabolically scale with size differently than animals with an internal circulatory system. In this case, metabolic rate is typically limited by surface to volume constraints to maintain an efficient supply of oxygen and food. Here, we consider the linkeage between oxygen concentration, the respiration rates of sponges and sponge size. RESULTS We explored respiration kinetics for individuals of the demosponge Halichondria panicea with varying numbers of aquiferous modules (nmodules = 1-102). From this work we establish relationships between the sponge size, module number, maximum respiration rate (Rmax) and the half-saturation constant, Km, which is the oxygen concentration producing half of the maximum respiration rate, Rmax. We found that the nmodules in H. panicea scales consistently with sponge volume (Vsp) and that Rmax increased with sponge size with a proportionality > 1. Conversly, we found a lack of correlation between Km and sponge body size suggesting that oxygen concentration does not control the size of sponges. CONCLUSIONS The present study reveals that the addition of aquiferous modules (with a mean volume of 1.59 ± 0.22 mL) enables H. panicea in particular, and likely demosponges in general, to grow far beyond constraints limiting the size of their component modules and independent of ambient oxygen levels.
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Affiliation(s)
- Lars Kumala
- Department of Biology, University of Southern Denmark, Odense M, 5230, Denmark.
- Marine Biological Research Centre, University of Southern Denmark, Kerteminde, 5300, Denmark.
- Nordcee, Department of Biology, University of Southern Denmark, Odense M, 5230, Denmark.
| | - Malte Thomsen
- Department of Biology, University of Southern Denmark, Odense M, 5230, Denmark
- Marine Biological Research Centre, University of Southern Denmark, Kerteminde, 5300, Denmark
- Nordcee, Department of Biology, University of Southern Denmark, Odense M, 5230, Denmark
| | - Donald E Canfield
- Department of Biology, University of Southern Denmark, Odense M, 5230, Denmark
- Nordcee, Department of Biology, University of Southern Denmark, Odense M, 5230, Denmark
- Danish Institute for Advanced Study (DIAS), University of Southern Denmark, Odense M, 5230, Denmark
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3
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Martins IS, Schrodt F, Blowes SA, Bates AE, Bjorkman AD, Brambilla V, Carvajal-Quintero J, Chow CFY, Daskalova GN, Edwards K, Eisenhauer N, Field R, Fontrodona-Eslava A, Henn JJ, van Klink R, Madin JS, Magurran AE, McWilliam M, Moyes F, Pugh B, Sagouis A, Trindade-Santos I, McGill BJ, Chase JM, Dornelas M. Widespread shifts in body size within populations and assemblages. Science 2023; 381:1067-1071. [PMID: 37676959 DOI: 10.1126/science.adg6006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 08/10/2023] [Indexed: 09/09/2023]
Abstract
Biotic responses to global change include directional shifts in organismal traits. Body size, an integrative trait that determines demographic rates and ecosystem functions, is thought to be shrinking in the Anthropocene. Here, we assessed the prevalence of body size change in six taxon groups across 5025 assemblage time series spanning 1960 to 2020. Using the Price equation to partition this change into within-species body size versus compositional changes, we detected prevailing decreases in body size through time driven primarily by fish, with more variable patterns in other taxa. We found that change in assemblage composition contributes more to body size changes than within-species trends, but both components show substantial variation in magnitude and direction. The biomass of assemblages remains quite stable as decreases in body size trade off with increases in abundance.
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Affiliation(s)
- Inês S Martins
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- Leverhulme Centre for Anthropocene Biodiversity, University of York, York YO10 5DD, UK
| | - Franziska Schrodt
- School of Geography, University of Nottingham, University Park, Nottingham NG7 2RD
| | - Shane A Blowes
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Amanda E Bates
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Anne D Bjorkman
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg 41319, Sweden
| | - Viviana Brambilla
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- MARE, Guia Marine Laboratory, Faculty of Sciences, University of Lisbon, Cascais 2750-374, Portugal
| | - Juan Carvajal-Quintero
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Institute of Biology, Leipzig University, Leipzig 04103, Germany
| | - Cher F Y Chow
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Gergana N Daskalova
- International Institute for Applied Systems Analysis (IIASA), Laxenburg 2361, Austria
| | - Kyle Edwards
- Department of Oceanography, University of Hawai''i at Mānoa, Honolulu, HI 96822, USA
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Institute of Biology, Leipzig University, Leipzig 04103, Germany
| | - Richard Field
- School of Geography, University of Nottingham, University Park, Nottingham NG7 2RD
| | - Ada Fontrodona-Eslava
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Jonathan J Henn
- Department of Evolution, Ecology, and Organismal Biology, University of California Riverside, Riverside, CA 92521, USA
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Roel van Klink
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Joshua S Madin
- Hawai''i Institute of Marine Biology, University of Hawai''i at Manoa, Kāne'ohe, Hawai''i 96744, USA
| | - Anne E Magurran
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Michael McWilliam
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Faye Moyes
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Brittany Pugh
- School of Geography, University of Nottingham, University Park, Nottingham NG7 2RD
- University College London, School of Geography, Gower Street, London WC1E 6AE, UK
| | - Alban Sagouis
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Isaac Trindade-Santos
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- Macroevolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1, Tancha, Onna-son, Kunigami-gun 904-0495, Okinawa, Japan
| | - Brian J McGill
- School of Biology and Ecology and Mitchell Center for Sustainability Solutions, University of Maine, Orono, ME 04469, USA
| | - Jonathan M Chase
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Maria Dornelas
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- Leverhulme Centre for Anthropocene Biodiversity, University of York, York YO10 5DD, UK
- MARE, Guia Marine Laboratory, Faculty of Sciences, University of Lisbon, Cascais 2750-374, Portugal
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Gasbarro R, Sowers D, Margolin A, Cordes EE. Distribution and predicted climatic refugia for a reef-building cold-water coral on the southeast US margin. GLOBAL CHANGE BIOLOGY 2022; 28:7108-7125. [PMID: 36054745 DOI: 10.1111/gcb.16415] [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: 05/25/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Climate change is reorganizing the planet's biodiversity, necessitating proactive management of species and habitats based on spatiotemporal predictions of distributions across climate scenarios. In marine settings, climatic changes will predominantly manifest via warming, ocean acidification, deoxygenation, and changes in hydrodynamics. Lophelia pertusa, the main reef-forming coral present throughout the deep Atlantic Ocean (>200 m), is particularly sensitive to such stressors with stark reductions in suitable habitat predicted to accrue by 2100 in a business-as-usual scenario. However, with new occurrence data for this species along with higher-resolution bathymetry and climate data, it may be possible to locate further climatic refugia. Here, we synthesize new and published biogeographic, geomorphological, and climatic data to build ensemble, multi-scale habitat suitability models for L. pertusa on the continental margin of the southeast United States (SEUS). We then project these models in two timepoints (2050, 2100) and four climate change scenarios to characterize the occurrence probability of this critical cold-water coral (CWC) habitat now and in the future. Our models reveal the extent of reef habitat in the SEUS and corroborate it as the largest currently known essentially continuous CWC reef province on earth, and also predict abundance of L. pertusa to identify key areas, including those outside areas currently protected from bottom-contact fishing. Drastic reductions in L. pertusa climatic suitability index emerged primarily after 2050 and were concentrated at the shallower end (<~550 m) of the regional distribution under the Gulf Stream main axis. Our results thus suggest a depth-driven climate refuge effect where deeper, cooler reef sites experience lesser declines. The strength of this effect increases with climate scenario severity. Taken together, our study has implications for the regional and global management of this species, portending changes in the biodiversity reliant on CWC habitats and the critical ecosystem services they provide.
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Affiliation(s)
- Ryan Gasbarro
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Derek Sowers
- NOAA Office of Ocean Exploration and Research, Durham, New Hampshire, USA
| | - Alex Margolin
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
| | - Erik E Cordes
- Department of Biology, Temple University, Philadelphia, Pennsylvania, USA
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5
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Sandra I, Verri T, Filice M, Barca A, Schiavone R, Gattuso A, Cerra MC. Shaping the cardiac response to hypoxia: NO and its partners in teleost fish. Curr Res Physiol 2022; 5:193-202. [PMID: 35434651 PMCID: PMC9010694 DOI: 10.1016/j.crphys.2022.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/14/2022] [Accepted: 03/31/2022] [Indexed: 12/12/2022] Open
Abstract
The reduced availability of dissolved oxygen is a common stressor in aquatic habitats that affects the ability of the heart to ensure tissue oxygen supply. Among key signalling molecules activated during cardiac hypoxic stress, nitric oxide (NO) has emerged as a central player involved in the related adaptive responses. Here, we outline the role of the nitrergic control in modulating tolerance and adaptation of teleost heart to hypoxia, as well as major molecular players that participate in the complex NO network. The purpose is to provide a framework in which to depict how the heart deals with limitations in oxygen supply. In this perspective, defining the relational interplay between the multiple (sets of) proteins that, due to the gene duplication events that occurred during the teleost fish evolutive radiation, do operate in parallel with similar functions in the (different) heart (districts) and other body districts under low levels of oxygen supply, represents a next goal of the comparative research in teleost fish cardiac physiology. The flexibility of the teleost heart to O2 limitations is illustrated by using cyprinids as hypoxia tolerance models. Major molecular mediators of the teleost cardiac response are discussed with a focus on the nitrergic system. A comparative analysis of gene duplication highlights conserved targets which may orchestrate the cardiac response to hypoxia.
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6
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Orio A, Heimbrand Y, Limburg K. Deoxygenation impacts on Baltic Sea cod: Dramatic declines in ecosystem services of an iconic keystone predator. AMBIO 2022; 51:626-637. [PMID: 34075555 PMCID: PMC8800964 DOI: 10.1007/s13280-021-01572-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/07/2021] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
The intensified expansion of the Baltic Sea's hypoxic zone has been proposed as one reason for the current poor status of cod (Gadus morhua) in the Baltic Sea, with repercussions throughout the food web and on ecosystem services. We examined the links between increased hypoxic areas and the decline in maximum length of Baltic cod, a demographic proxy for services generation. We analysed the effect of different predictors on maximum length of Baltic cod during 1978-2014 using a generalized additive model. The extent of minimally suitable areas for cod (oxygen concentration ≥ 1 ml l-1) is the most important predictor of decreased cod maximum length. We also show, with simulations, the potential for Baltic cod to increase its maximum length if hypoxic areal extent is reduced to levels comparable to the beginning of the 1990s. We discuss our findings in relation to ecosystem services affected by the decrease of cod maximum length.
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Affiliation(s)
- Alessandro Orio
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Turistgatan 5, 453 30 Lysekil, Sweden
| | - Yvette Heimbrand
- Department of Aquatic Resources, Institute of Coastal Research, Swedish University of Agricultural Sciences, Skolgatan 6, 742 42 Öregrund, Sweden
| | - Karin Limburg
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Turistgatan 5, 453 30 Lysekil, Sweden
- College of Environmental Science and Forestry, State University of New York, Syracuse, NY USA
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7
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Oxygen consumption during and post-hypoxia exposure in bearded fireworms (Annelida: Amphinomidae). J Comp Physiol B 2020; 190:681-689. [PMID: 32960287 DOI: 10.1007/s00360-020-01308-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/10/2020] [Accepted: 09/09/2020] [Indexed: 10/23/2022]
Abstract
Oxygen is necessary for all marine animals to support metabolic functions. When chronic low dissolved oxygen (DO) conditions occur, organisms must adjust to overcome this stressor's effect on metabolic rates. The bearded fireworm, Hermodice carunculata, is a widespread species frequently exposed to hypoxic conditions in areas within its broad distribution which may impact metabolism, wound healing, and regeneration. To study the impact of hypoxia on their metabolic rates, we exposed fireworms to two levels of lower than normal DO conditions (low 2.5 ± 0.25 mg O2 L-1 and mid 4.5 ± 0.25 mg O2 L-1) for 7 days by pumping nitrogen into their holding tanks. During a chronic hypoxia trial, we quantified oxygen consumption in each experimental group and subsequently determined post-hypoxia oxygen consumption of individuals from the lowest oxygen level. During the hypoxic exposure, the oxygen uptake rates declined in low and mid DO conditions, while remaining relatively constant for the normoxic (7.0 ± 0.25 mg O2 L-1) control. We then compared the oxygen consumption rates from the lowest DO condition to fireworms likely never exposed to hypoxia and fireworms from a location likely to be exposed to hypoxia. We found higher oxygen consumption rates in the experimentally hypoxia-exposed worms. These results suggest prolonged negative impacts of hypoxic exposure, leading to a lasting elevation of metabolic rates of these marine invertebrates. The increase in metabolic rates may lead to increased predation on their prey of choice, economically and commercially important coral, causing increased degradation of already threatened coral reef ecosystems.
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8
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Hainey MAH, Emlet RB. Gorgonocephalus eucnemis (Echinodermata: Ophiuroidea) and Bursal Ventilation. THE BIOLOGICAL BULLETIN 2020; 238:193-205. [PMID: 32597717 DOI: 10.1086/709575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The basket star Gorgonocephalus eucnemis is an aerobic organism highly dependent on dissolved oxygen in surrounding waters. Previous observations on the anatomy of Gorgonocephalus state that five pairs of ossicles (the radial shields and genital plates) regulate the position of the roof of the body disc and are responsible for flushing seawater into and out of the bursae, though this seems never to have been empirically tested. In the current study, rates of bursal ventilation were investigated in response to an increase in the availability of food and, separately, exposure to hypoxic levels of dissolved oxygen. When fed with suspended krill particles, basket stars increased rates of bursal ventilation, ranging from 13% to 155%, resulting in a similar increase in volume of water moved in and out of bursae. This rate remained elevated for an average of 25 minutes after active feeding ended. Bursal ventilation rates also increased significantly (~60% average increase) when basket stars were exposed to hypoxic conditions (dissolved oxygen ≤ 3.5 mg O2 L-1 = 2.45 mL O2 L-1). Some specimens exhibited a loss of coordination in hypoxic conditions. All specimens recovered and resumed a normal rate of bursal ventilation when returned to normoxic conditions. Measurements show that dissolved oxygen levels decreased from outside to inside bursae and suggest that dissolved oxygen is absorbed in bursae during bursal ventilations. Increasing rates of bursal ventilation may help meet the increased oxygen demands when feeding and may help animals endure some exposures to hypoxia.
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9
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Tunnicliffe V, Gasbarro R, Juanes F, Qualley J, Soderberg N, Chu JWF. An hypoxia-tolerant flatfish: consequences of sustained stress on the slender sole Lyopsetta exilis (Pleuronectidae) in the context of a changing ocean. JOURNAL OF FISH BIOLOGY 2020; 96:394-407. [PMID: 31755100 PMCID: PMC7028253 DOI: 10.1111/jfb.14212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/21/2019] [Indexed: 06/10/2023]
Abstract
Slender sole Lyopsetta exilis is an abundant groundfish on the continental shelf and inner waters of British Columbia, Canada, where it reaches a maximum standard length of 44 cm. Benthic image surveys coupled with oxygen measurements in Saanich Inlet document a dense population in bottom conditions near anoxia (0.03 ml l-1 oxygen) where diel migrating zooplankton intersect the bottom; we confirm this species is a planktivore, which limits its depth range to the base of the migration layer. In a comparison with slender sole from a nearby well-oxygenated habitat, several probable effects of living in severe hypoxia emerge: both sexes are significantly smaller in Saanich and the sex ratio is male-skewed. Otoliths from the Saanich fish were difficult to read due to many checks, but both sexes were smaller at age with the largest female (20 cm) from the hypoxia zone registering 17 years. Hypoxia appears to have a direct consequence on growth despite good food supply in this productive basin. Hyperventilation, a low metabolic rate and a very low critical oxygen tension help this fish regulate oxygen uptake in severely hypoxic conditions; it will be particularly resilient as the incidence of hypoxia increases on the continental shelf. Data from small-mesh bottom-trawl surveys over four decades reveal an increase in mean annual catch per unit effort in southern regions of the province, including the outer shelf and the Strait of Georgia. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) ichthyoplankton database records a general decline in fish larvae on the Oregon-California shelf since 1990, but slender sole larvae are increasing there, as they are in the Strait of Georgia. We project that the slender sole will gain relative benefits in the future warming, deoxygenated northeast Pacific Ocean.
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Affiliation(s)
- Verena Tunnicliffe
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
- School of Earth & Ocean SciencesUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Ryan Gasbarro
- School of Earth & Ocean SciencesUniversity of VictoriaVictoriaBritish ColumbiaCanada
- Department of BiologyTemple UniversityPhiladelphiaPennsylvaniaUSA
| | - Francis Juanes
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Jessica Qualley
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Nicole Soderberg
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
| | - Jackson W. F. Chu
- Department of BiologyUniversity of VictoriaVictoriaBritish ColumbiaCanada
- Department of Ocean SciencesMemorial University of NewfoundlandSt. John'sNewfoundlandCanada
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10
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Wang W, Zhong P, Yi JQ, Xu AX, Lin WY, Guo ZC, Wang CG, Sun CB, Chan S. Potential role for microRNA in facilitating physiological adaptation to hypoxia in the Pacific whiteleg shrimp Litopenaeus vannamei. FISH & SHELLFISH IMMUNOLOGY 2019; 84:361-369. [PMID: 30291981 DOI: 10.1016/j.fsi.2018.09.079] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/27/2018] [Accepted: 09/29/2018] [Indexed: 06/08/2023]
Abstract
Hypoxia is one of the most common physiological stressors in shrimp farming. Post-transcriptional regulation by microRNAs has been recognized as a ubiquitous strategy to enable transient phenotypic plasticity and adaptation to stressful environment, but involvement of microRNAs in hypoxia stress response of penaeid shrimp remains elusive. In this study, small RNA sequencing and comparative transcriptomic analysis was conducted to construct a comprehensive microRNA dataset for the whiteleg shrimp Litopenaeus vannamei exposed to hypoxia challenge. A total of 3324 known miRNAs and 8 putative novel miRNAs were identified, providing a valuable resource for future investigation on the functional mechanism of miRNAs in shrimp. Upon hypoxia, 1213 miRNAs showed significant differential expression, and many well-known miRNAs involved in hypoxia tolerance such as miR-210, let-7, miR-143 and miR-101 were identified. Remarkably, the vast majority of these miRNAs were up-regulated, suggesting that up-regulation of miRNAs may represent an effective strategy to inhibit protein translation under stressful hypoxic condition. The differentially expressed miRNAs were potentially targeting a wide variety of genes, including those with essential roles in hypoxia tolerance such as HIF1a and p53. GO and KEGG enrichment analysis further revealed that a broad range of biological processes and metabolic pathways were over-represented. Several GO terms associated with gene transcription and translation and KEGG pathways related to cytoskeleton remodeling, immune defense and signaling transduction were enriched, highlighting the crucial roles of these cellular events in the adaptation to hypoxia. Taken together, our study revealed that the differentially expressed miRNAs may regulate host response to hypoxia by modulating the expression of stress response genes such as HIF1a and p53 and affecting key cellular events involved in hypoxia adaptation. The findings would expand our knowledge of the biochemical and molecular underpinnings of hypoxia response strategies used by penaeid shrimp, and contribute to a better understanding of the molecular mechanisms of hypoxia tolerance in decapod crustaceans.
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Affiliation(s)
- Wei Wang
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Ping Zhong
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Jun-Qiao Yi
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Ai-Xuan Xu
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Wen-Yi Lin
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Zhen-Cong Guo
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Cheng-Gui Wang
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China
| | - Cheng-Bo Sun
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China.
| | - Siuming Chan
- College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, PR China.
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11
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Gallo ND, Levin LA, Beckwith M, Barry JP. Home sweet suboxic home: remarkable hypoxia tolerance in two demersal fish species in the Gulf of California. Ecology 2018; 100:e02539. [PMID: 30480802 DOI: 10.1002/ecy.2539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/28/2018] [Accepted: 09/10/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Natalya D Gallo
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA.,Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA
| | - Lisa A Levin
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA.,Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA
| | - Maryanne Beckwith
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, 92093, USA
| | - James P Barry
- Monterey Bay Aquarium Research Institute, Moss Landing, California, 95039, USA
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12
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Benton MJ. Hyperthermal-driven mass extinctions: killing models during the Permian-Triassic mass extinction. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:20170076. [PMID: 30177561 PMCID: PMC6127390 DOI: 10.1098/rsta.2017.0076] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/23/2018] [Indexed: 05/06/2023]
Abstract
Many mass extinctions of life in the sea and on land have been attributed to geologically rapid heating, and in the case of the Permian-Triassic and others, driven by large igneous province volcanism. The Siberian Traps eruptions raised ambient temperatures to 35-40°C. A key question is how massive eruptions during these events, and others, could have killed life in the sea and on land; proposed killers are reviewed here. In the oceans, benthos and plankton were killed by anoxia-euxinia and lethal heating, respectively, and the habitable depth zone was massively reduced. On land, the combination of extreme heating and drought reduced the habitable land area, and acid rain stripped forests and soils. Physiological experiments show that some animals can adapt to temperature rises of a few degrees, and that some can survive short episodes of increases of 10°C. However, most plants and animals suffer major physiological damage at temperatures of 35-40°C. Studies of the effects of extreme physical conditions on modern organisms, as well as assumptions about rates of environmental change, give direct evidence of likely killing effects deriving from hyperthermals of the past.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
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Affiliation(s)
- Michael J Benton
- School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK
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Krogh J, Ianson D, Hamme RC, Lowe CJ. Risks of hypoxia and acidification in the high energy coastal environment near Victoria, Canada's untreated municipal sewage outfalls. MARINE POLLUTION BULLETIN 2018; 133:517-531. [PMID: 30041345 DOI: 10.1016/j.marpolbul.2018.05.018] [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: 08/21/2017] [Revised: 05/04/2018] [Accepted: 05/10/2018] [Indexed: 06/08/2023]
Abstract
Wastewater disposal often has deleterious impacts on the receiving environment. Low dissolved oxygen levels are particularly concerning. Here, we investigate the impacts on dissolved oxygen and carbon chemistry of screened municipal wastewater in the marine waters off Victoria, Canada. We analyzed data from undersea moorings, ship-based monitoring, and remotely-operated vehicle video. We used these observations to construct a two-layer model of the nearfield receiving environment. Despite the lack of advanced treatment, dissolved oxygen levels near the outfalls were well above a 62 μmol kg-1 hypoxic threshold. Furthermore, the impact on water column oxygen at the outfall is likely <2 μmol kg-1. Dissolved inorganic carbon is not elevated and pH not depressed compared to the surrounding region. Strong tidal currents and cold, well-ventilated waters give Victoria's marine environment a high assimilative capacity for organic waste. However, declining oxygen levels offshore put water near the outfall at risk of future hypoxia.
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Affiliation(s)
- Jeremy Krogh
- School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada; Capital Regional District, Victoria, British Columbia, Canada.
| | - Debby Ianson
- School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada; Fisheries and Oceans Canada, Institute of Ocean Sciences, Sidney, British Columbia, Canada.
| | - Roberta C Hamme
- School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada.
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Fajardo M, Andrade D, Bonicelli J, Bon M, Gómez G, Riascos JM, Pacheco AS. Macrobenthic communities in a shallow normoxia to hypoxia gradient in the Humboldt upwelling ecosystem. PLoS One 2018; 13:e0200349. [PMID: 30016340 PMCID: PMC6049901 DOI: 10.1371/journal.pone.0200349] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/25/2018] [Indexed: 11/18/2022] Open
Abstract
Hypoxia is one of the most important stressors affecting the health conditions of coastal ecosystems. In highly productive ecosystems such as the Humboldt Current ecosystem, the oxygen minimum zone is an important abiotic factor modulating the structure of benthic communities over the continental shelf. Herein, we study soft-bottom macrobenthic communities along a depth gradient-at 10, 20, 30 and 50 m-for two years to understand how hypoxia affects the structure of shallow communities at two sites in Mejillones Bay (23°S) in northern Chile. We test the hypothesis that, during months with shallow hypoxic zones, community structure will be much more dissimilar, thereby depicting a clear structural gradient with depth and correlated abiotic variables (e.g. organic matter, temperature and salinity). Likewise, during conditions of deeper hypoxic zones, communities will be similar among habitats as they could develop structure via succession in conditions with less stress. Throughout the sampling period (October 2015 to October 2017), the water column was hypoxic (from 2 to 0.5ml/l O2) most of the time, reaching shallow depths of 20 to 10 m. Only one episode of oxygenation was detected in June 2016, where normoxia (>2ml/l O2) reached down to 50 m. The structure of the communities depicted a clear pattern of increasing dissimilarity from shallow normoxic and deep hypoxic habitat. This pattern was persistent throughout time despite the occurrence of an oxygenation episode. Contrasting species abundance and biomass distribution explained the gradient in structure, arguably reflecting variable levels of hypoxia adaptation, i.e. few polychaetes such as Magelona physilia and Paraprionospio pinnata were only located in low oxygen habitats. The multivariable dispersion of community composition as a proxy of beta diversity decreased significantly with depth, suggesting loss of community structure and variability when transitioning from normoxic to hypoxic conditions. Our results show the presence of semi-permanent shallow hypoxia at Mejillones Bay, constraining diverse and more variable communities at a very shallow depth (10-20 m). These results must be considered in the context of the current decline of dissolved oxygen in most oceans and coastal regions and their impact on seabed biota.
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Affiliation(s)
- Maritza Fajardo
- Magister en Ecología de Sistemas Acuáticos, Universidad de Antofagasta, Antofagasta, Chile
| | - Diego Andrade
- CENSOR Laboratory, Universidad de Antofagasta, Antofagasta, Chile
| | - Jessica Bonicelli
- Estación Costera de Investigaciones Marinas, Pontificia Universidad Católica de Chile, Santiago de Chile, Chile
- Departamento de Oceanografía y Medio Ambiente, Instituto de Fomento Pesquero, Valparaíso, Chile
| | - Melanie Bon
- Programa de Doctorado en Ciencias Aplicadas mención Sistemas Marinos Costeros, Universidad de Antofagasta, Antofagasta, Chile
| | - Gonzalo Gómez
- Magister en Ecología de Sistemas Acuáticos, Universidad de Antofagasta, Antofagasta, Chile
| | - José M. Riascos
- Estuaries & Mangroves Research group, Universidad del Valle, Cali, Colombia
| | - Aldo S. Pacheco
- CENSOR Laboratory, Instituto de Ciencias Naturales Alexander von Humboldt, Universidad de Antofagasta, Antofagasta, Chile
- * E-mail:
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15
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Chu JWF, Curkan C, Tunnicliffe V. Drivers of temporal beta diversity of a benthic community in a seasonally hypoxic fjord. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172284. [PMID: 29765677 PMCID: PMC5936942 DOI: 10.1098/rsos.172284] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/13/2018] [Indexed: 05/03/2023]
Abstract
Global expansion of oxygen-deficient (hypoxic) waters will have detrimental effects on marine life in the Northeast Pacific Ocean (NEP) where some of the largest proportional losses in aerobic habitat are predicted to occur. However, few in situ studies have accounted for the high environmental variability in this region while including natural community-assembly dynamics. Here, we present results from a 14-month deployment of a benthic camera platform tethered to the VENUS cabled observatory in the seasonally hypoxic Saanich Inlet. Our time series continuously recorded natural cycles of deoxygenation and reoxygenation that allowed us to test whether a community from the NEP showed hysteresis in its recovery compared to hypoxia-induced decline, and to address the processes driving temporal beta diversity under variable states of hypoxia. Using high-frequency ecological time series, we reveal (i) differences in the response and recovery of the epibenthic community are rate-limited by recovery of the sessile species assemblage; (ii) both environmental and biological processes influence community assembly patterns at multiple timescales; and (iii) interspecific processes can drive temporal beta diversity in seasonal hypoxia. Ultimately, our results illustrate how different timescale-dependent drivers can influence the response and recovery of a marine habitat under increasing stress from environmental change.
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Affiliation(s)
- Jackson W. F. Chu
- Department of Biology, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
- Fisheries and Oceans Canada, Institute of Ocean Sciences, Sidney, BC V8 L 4B2, Canada
- Author for correspondence: Jackson W. F. Chu e-mail:
| | - Curtis Curkan
- School of Earth & Ocean Sciences, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
| | - Verena Tunnicliffe
- Department of Biology, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
- School of Earth & Ocean Sciences, University of Victoria, PO Box 3080, Victoria, BC V8 W 2Y2, Canada
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McCormick LR, Levin LA. Physiological and ecological implications of ocean deoxygenation for vision in marine organisms. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0322. [PMID: 28784712 PMCID: PMC5559417 DOI: 10.1098/rsta.2016.0322] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/18/2017] [Indexed: 05/04/2023]
Abstract
Climate change has induced ocean deoxygenation and exacerbated eutrophication-driven hypoxia in recent decades, affecting the physiology, behaviour and ecology of marine organisms. The high oxygen demand of visual tissues and the known inhibitory effects of hypoxia on human vision raise the questions if and how ocean deoxygenation alters vision in marine organisms. This is particularly important given the rapid loss of oxygen and strong vertical gradients in oxygen concentration in many areas of the ocean. This review evaluates the potential effects of low oxygen (hypoxia) on visual function in marine animals and their implications for marine biota under current and future ocean deoxygenation based on evidence from terrestrial and a few marine organisms. Evolutionary history shows radiation of eye designs during a period of increasing ocean oxygenation. Physiological effects of hypoxia on photoreceptor function and light sensitivity, in combination with morphological changes that may occur throughout ontogeny, have the potential to alter visual behaviour and, subsequently, the ecology of marine organisms, particularly for fish, cephalopods and arthropods with 'fast' vision. Visual responses to hypoxia, including greater light requirements, offer an alternative hypothesis for observed habitat compression and shoaling vertical distributions in visual marine species subject to ocean deoxygenation, which merits further investigation.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.
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Affiliation(s)
- Lillian R McCormick
- Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA
| | - Lisa A Levin
- Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA
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17
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Klein SG, Pitt KA, Nitschke MR, Goyen S, Welsh DT, Suggett DJ, Carroll AR. Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian. GLOBAL CHANGE BIOLOGY 2017; 23:3690-3703. [PMID: 28390081 DOI: 10.1111/gcb.13718] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/28/2017] [Accepted: 04/02/2017] [Indexed: 05/23/2023]
Abstract
Anthropogenic nutrient inputs enhance microbial respiration within many coastal ecosystems, driving concurrent hypoxia and acidification. During photosynthesis, Symbiodinium spp., the microalgal endosymbionts of cnidarians and other marine phyla, produce O2 and assimilate CO2 and thus potentially mitigate the exposure of the host to these stresses. However, such a role for Symbiodinium remains untested for noncalcifying cnidarians. We therefore contrasted the fitness of symbiotic and aposymbiotic polyps of a model host jellyfish (Cassiopea sp.) under reduced O2 (~2.09 mg/L) and pH (~ 7.63) scenarios in a full-factorial experiment. Host fitness was characterized as asexual reproduction and their ability to regulate internal pH and Symbiodinium performance characterized by maximum photochemical efficiency, chla content and cell density. Acidification alone resulted in 58% more asexual reproduction of symbiotic polyps than aposymbiotic polyps (and enhanced Symbiodinium cell density) suggesting Cassiopea sp. fitness was enhanced by CO2 -stimulated Symbiodinium photosynthetic activity. Indeed, greater CO2 drawdown (elevated pH) was observed within host tissues of symbiotic polyps under acidification regardless of O2 conditions. Hypoxia alone produced 22% fewer polyps than ambient conditions regardless of acidification and symbiont status, suggesting Symbiodinium photosynthetic activity did not mitigate its effects. Combined hypoxia and acidification, however, produced similar numbers of symbiotic polyps compared with aposymbiotic kept under ambient conditions, demonstrating that the presence of Symbiodinium was key for mitigating the combined effects of hypoxia and acidification on asexual reproduction. We hypothesize that this mitigation occurred because of reduced photorespiration under elevated CO2 conditions where increased net O2 production ameliorates oxygen debt. We show that Symbiodinium play an important role in facilitating enhanced fitness of Cassiopea sp. polyps, and perhaps also other noncalcifying cnidarian hosts, to the ubiquitous effects of ocean acidification. Importantly we highlight that symbiotic, noncalcifying cnidarians may be particularly advantaged in productive coastal waters that are subject to simultaneous hypoxia and acidification.
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Affiliation(s)
- Shannon G Klein
- Australian Rivers Institute - Coasts and Estuaries, Griffith School of Environment, Griffith University, Gold Coast, Qld, Australia
- Red Sea Research Center (RSRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Kylie A Pitt
- Australian Rivers Institute - Coasts and Estuaries, Griffith School of Environment, Griffith University, Gold Coast, Qld, Australia
| | - Matthew R Nitschke
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, Australia
| | - Samantha Goyen
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, Australia
| | - David T Welsh
- Environmental Futures Research Institute, Griffith School of Environment, Griffith University, Gold Coast, Qld, Australia
| | - David J Suggett
- Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, Australia
| | - Anthony R Carroll
- Environmental Futures Research Institute, Griffith School of Environment, Griffith University, Gold Coast, Qld, Australia
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Doya C, Chatzievangelou D, Bahamon N, Purser A, De Leo FC, Juniper SK, Thomsen L, Aguzzi J. Seasonal monitoring of deep-sea megabenthos in Barkley Canyon cold seep by internet operated vehicle (IOV). PLoS One 2017; 12:e0176917. [PMID: 28557992 PMCID: PMC5448723 DOI: 10.1371/journal.pone.0176917] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 04/19/2017] [Indexed: 11/19/2022] Open
Abstract
Knowledge of the processes shaping deep-sea benthic communities at seasonal scales in cold-seep environments is incomplete. Cold seeps within highly dynamic regions, such as submarine canyons, where variable current regimes may occur, are particularly understudied. Novel Internet Operated Vehicles (IOVs), such as tracked crawlers, provide new techniques for investigating these ecosystems over prolonged periods. In this study a benthic crawler connected to the NEPTUNE cabled infrastructure operated by Ocean Networks Canada was used to monitor community changes across 60 m2 of a cold-seep area of the Barkley Canyon, North East Pacific, at ~890 m depth within an Oxygen Minimum Zone (OMZ). Short video-transects were run at 4-h intervals during the first week of successive calendar months, over a 14 month period (February 14th 2013 to April 14th 2014). Within each recorded transect video megafauna abundances were computed and changes in environmental conditions concurrently measured. The responses of fauna to environmental conditions as a proxy of seasonality were assessed through analysis of abundances in a total of 438 video-transects (over 92 h of total footage). 7698 fauna individuals from 6 phyla (Cnidaria, Ctenophora, Arthropoda, Echinodermata, Mollusca, and Chordata) were logged and patterns in abundances of the 7 most abundant taxa (i.e. rockfish Sebastidae, sablefish Anoplopoma fimbria, hagfish Eptatretus stoutii, buccinids (Buccinoidea), undefined small crabs, ctenophores Bolinopsis infundibulum, and Scyphomedusa Poralia rufescens) were identified. Patterns in the reproductive behaviour of the grooved tanner crab (Chionnecetes tanneri) were also indicated. Temporal variations in biodiversity and abundance in megabenthic fauna was significantly influenced by variabilities in flow velocity flow direction (up or down canyon), dissolved oxygen concentration and month of study. Also reported here for the first time are transient mass aggregations of grooved tanner crabs through these depths of the canyon system, in early spring and likely linked to the crab's reproductive cycle.
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Affiliation(s)
- Carolina Doya
- Instituto de Ciencias del Mar (ICM-CSIC), Barcelona, Spain
- * E-mail: (CD); (JA)
| | | | - Nixon Bahamon
- Centro de Estudios Avanzados de Blanes (CEAB-CSIC), Blanes, Spain
| | - Autun Purser
- Deep Sea Ecology and Technology group, Alfred-Wegener-Institute (AWI), Bremerhaven, Germany
| | - Fabio C. De Leo
- Ocean Networks Canada, University of Victoria, Victoria, BC, Canada
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - S. Kim Juniper
- Ocean Networks Canada, University of Victoria, Victoria, BC, Canada
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | | | - Jacopo Aguzzi
- Instituto de Ciencias del Mar (ICM-CSIC), Barcelona, Spain
- * E-mail: (CD); (JA)
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Sperling EA, Frieder CA, Levin LA. Biodiversity response to natural gradients of multiple stressors on continental margins. Proc Biol Sci 2017; 283:rspb.2016.0637. [PMID: 27122565 DOI: 10.1098/rspb.2016.0637] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/06/2016] [Indexed: 12/13/2022] Open
Abstract
Sharp increases in atmospheric CO2 are resulting in ocean warming, acidification and deoxygenation that threaten marine organisms on continental margins and their ecological functions and resulting ecosystem services. The relative influence of these stressors on biodiversity remains unclear, as well as the threshold levels for change and when secondary stressors become important. One strategy to interpret adaptation potential and predict future faunal change is to examine ecological shifts along natural gradients in the modern ocean. Here, we assess the explanatory power of temperature, oxygen and the carbonate system for macrofaunal diversity and evenness along continental upwelling margins using variance partitioning techniques. Oxygen levels have the strongest explanatory capacity for variation in species diversity. Sharp drops in diversity are seen as O2 levels decline through the 0.5-0.15 ml l(-1) (approx. 22-6 µM; approx. 21-5 matm) range, and as temperature increases through the 7-10°C range. pCO2 is the best explanatory variable in the Arabian Sea, but explains little of the variance in diversity in the eastern Pacific Ocean. By contrast, very little variation in evenness is explained by these three global change variables. The identification of sharp thresholds in ecological response are used here to predict areas of the seafloor where diversity is most at risk to future marine global change, noting that the existence of clear regional differences cautions against applying global thresholds.
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Affiliation(s)
- Erik A Sperling
- Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA
| | - Christina A Frieder
- Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA
| | - Lisa A Levin
- Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, La Jolla, CA 92093-0218, USA
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Gallo ND, Levin LA. Fish Ecology and Evolution in the World's Oxygen Minimum Zones and Implications of Ocean Deoxygenation. ADVANCES IN MARINE BIOLOGY 2016; 74:117-198. [PMID: 27573051 DOI: 10.1016/bs.amb.2016.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Oxygen minimum zones (OMZs) and oxygen limited zones (OLZs) are important oceanographic features in the Pacific, Atlantic, and Indian Ocean, and are characterized by hypoxic conditions that are physiologically challenging for demersal fish. Thickness, depth of the upper boundary, minimum oxygen levels, local temperatures, and diurnal, seasonal, and interannual oxycline variability differ regionally, with the thickest and shallowest OMZs occurring in the subtropics and tropics. Although most fish are not hypoxia-tolerant, at least 77 demersal fish species from 16 orders have evolved physiological, behavioural, and morphological adaptations that allow them to live under the severely hypoxic, hypercapnic, and at times sulphidic conditions found in OMZs. Tolerance to OMZ conditions has evolved multiple times in multiple groups with no single fish family or genus exploiting all OMZs globally. Severely hypoxic conditions in OMZs lead to decreased demersal fish diversity, but fish density trends are variable and dependent on region-specific thresholds. Some OMZ-adapted fish species are more hypoxia-tolerant than most megafaunal invertebrates and are present even when most invertebrates are excluded. Expansions and contractions of OMZs in the past have affected fish evolution and diversity. Current patterns of ocean warming are leading to ocean deoxygenation, causing the expansion and shoaling of OMZs, which is expected to decrease demersal fish diversity and alter trophic pathways on affected margins. Habitat compression is expected for hypoxia-intolerant species, causing increased susceptibility to overfishing for fisheries species. Demersal fisheries are likely to be negatively impacted overall by the expansion of OMZs in a warming world.
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Affiliation(s)
- N D Gallo
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States.
| | - L A Levin
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States
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