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Comans CM, Smart SM, Kast ER, Lu Y, Lüdecke T, Leichliter JN, Sigman DM, Ikejiri T, Martínez-García A. Enameloid-bound δ 15 N reveals large trophic separation among Late Cretaceous sharks in the northern Gulf of Mexico. GEOBIOLOGY 2024; 22:e12585. [PMID: 38385603 DOI: 10.1111/gbi.12585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/21/2023] [Accepted: 01/03/2024] [Indexed: 02/23/2024]
Abstract
The nitrogen isotopic composition (15 N/14 N ratio, or δ15 N) of enameloid-bound organic matter (δ15 NEB ) in shark teeth was recently developed to investigate the biogeochemistry and trophic structures (i.e., food webs) of the ancient ocean. Using δ15 NEB , we present the first nitrogen isotopic evidence for trophic differences between shark taxa from a single fossil locality. We analyze the teeth of four taxa (Meristodonoides, Ptychodus, Scapanorhynchus, and Squalicorax) from the Late Cretaceous (83-84 Ma) Trussells Creek site in Alabama, USA, and compare the N isotopic findings with predictions from tooth morphology, the traditional method for inferring shark paleo-diets. Our δ15 NEB data indicate two distinct trophic groups, with averages separated by 6.1 ± 2.1‰. The lower group consists of Meristodonoides and Ptychodus, and the higher group consists of Scapanorhynchus and Squalicorax (i.e., lamniforms). This δ15 NEB difference indicates a 1.5 ± 0.5 trophic-level separation between the two groups, a finding that is in line with paleontological predictions of a higher trophic level for these lamniforms over Meristodonoides and Ptychodus. However, the δ15 NEB of Meristodonoides is lower than suggested by tooth morphology, although consistent with mechanical tests suggesting that higher trophic-level bony fishes were not a major component of their diet. Further, δ15 NEB indicates that the two sampled lamniform taxa fed at similar trophic levels despite their different inferred tooth functions. These two findings suggest that tooth morphology alone may not always be a sufficient indicator of dietary niche. The large trophic separation revealed by the δ15 NEB offset leaves open the possibility that higher trophic-level lamniforms, such as those measured here, preyed upon smaller, lower trophic-level sharks like Meristodonoides.
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Affiliation(s)
- Chelsea M Comans
- Department of Geological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA
| | - Sandi M Smart
- Department of Geological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA
- Max Plank Institute for Chemistry, Mainz, Germany
| | - Emma R Kast
- Department of Earth Sciences, University of Cambridge, Cambridge, UK
| | - YueHan Lu
- Department of Geological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA
| | - Tina Lüdecke
- Max Plank Institute for Chemistry, Mainz, Germany
| | | | - Daniel M Sigman
- Department of Geosciences, Princeton University, Princeton, New Jersey, USA
| | - Takehito Ikejiri
- Department of Geological Sciences, The University of Alabama, Tuscaloosa, Alabama, USA
- Alabama Museum of Natural History, The University of Alabama, Tuscaloosa, Alabama, USA
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Alma L, Fiamengo CJ, Alin SR, Jackson M, Hiromoto K, Padilla-Gamiño JL. Physiological responses of scallops and mussels to environmental variability: Implications for future shellfish aquaculture. MARINE POLLUTION BULLETIN 2023; 194:115356. [PMID: 37633025 DOI: 10.1016/j.marpolbul.2023.115356] [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: 01/18/2023] [Revised: 07/27/2023] [Accepted: 07/29/2023] [Indexed: 08/28/2023]
Abstract
Puget Sound (Washington, USA) is a large estuary, known for its profitable shellfish aquaculture industry. However, in the past decade, scientists have observed strong acidification, hypoxia, and temperature anomalies in Puget Sound. These co-occurring environmental stressors are a threat to marine ecosystems and shellfish aquaculture. Our research assesses how environmental variability in Puget Sound impacts two ecologically and economically important bivalves, the purple-hinge rock scallop (Crassodoma gigantea) and Mediterranean mussel (Mytilus galloprovincialis). Our study examines the effect of depth and seasonality on the physiology of these two important bivalves to gain insight into ideal grow-out conditions in an aquaculture setting, improving the yield and quality of this sustainable protein source. To do this, we used Hood Canal (located in Puget Sound) as a natural multiple-stressor laboratory, which allowed us to study acclimatization capacity of shellfish in their natural habitat and provide the aquaculture industry information about differences in growth rate, shell strength, and nutritional sources across depths and seasons. Bivalves were outplanted at two depths (5 and 30 m) and collected after 3.5 and 7.5 months. To maximize mussel and scallop growth potential in an aquaculture setting, our results suggest outplanting at 5 m depth, with more favorable oxygen and pH levels. Mussel shell integrity can be improved by placing out at 5 m, regardless of season, however, there were no notable differences in shell strength between depths in scallops. For both species, δ13C values were lowest at 5 m in the winter and δ15N was highest at 30 m regardless of season. Puget Sound's combination of naturally and anthropogenically acidified conditions is already proving to be a challenge for shellfish farmers. Our study provides crucial information to farmers to optimize aquaculture grow-out as we begin to navigate the impacts of climate change.
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Affiliation(s)
- Lindsay Alma
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St., Seattle, WA 98195, USA; Bodega Marine Laboratory, College of Biological Sciences, University of California, Davis, 2099 Westshore Rd., Bodega Bay, CA 94923, USA.
| | - Courtney J Fiamengo
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St., Seattle, WA 98195, USA
| | - Simone R Alin
- National Oceanic & Atmospheric Administration/Pacific Marine Environmental Laboratory (NOAA/PMEL), 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - Molly Jackson
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St., Seattle, WA 98195, USA; Taylor Shellfish Hatchery, 701 Broadspit Rd., Quilcene, WA 98376, USA
| | - Kris Hiromoto
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St., Seattle, WA 98195, USA
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Mele I, McGill RAR, Thompson J, Fennell J, Fitzer S. Ocean acidification, warming and feeding impacts on biomineralization pathways and shell material properties of Magallana gigas and Mytilus spp. MARINE ENVIRONMENTAL RESEARCH 2023; 186:105925. [PMID: 36857940 DOI: 10.1016/j.marenvres.2023.105925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 02/10/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Molluscs are among the organisms affected by ocean acidification (OA), relying on carbon for shell biomineralization. Metabolic and environmental sourcing are two pathways potentially affected by OA, but the circumstances and patterns by which they are altered are poorly understood. From previous studies, mollusc shells grown under OA appear smaller in size, brittle and thinner, suggesting an important alteration in carbon sequestration. However, supplementary feeding experiments have shown promising results in offsetting the negative consequences of OA on shell growth. Our study compared carbon uptake by δ13C tracing and deposition into mantle tissue and shell layers in Magallana gigas and Mytilus species, two economically valuable and common species. After subjecting the species to 7.7 pH, +2 °C seawater, and enhanced feeding, both species maintain shell growth and metabolic pathways under OA without benefitting from extra feeding, thus, showing effective acclimation to rapid and short-term environmental change. Mytilus spp. increases metabolic carbon into the calcite and environmental sourcing of carbon into the shell aragonite in low pH and high temperature conditions. Low pH affects M. gigas mantle nitrogen isotopes maintaining growth. Calcite biomineralization pathway differs between the two species and suggests species-specific response to OA.
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Affiliation(s)
- Isabella Mele
- Institute of Aquaculture, University of Stirling, Stirling, FK94LA, United Kingdom
| | - Rona A R McGill
- Stable Isotope Ecology Lab, Scottish Universities Environmental Research Centre, University of Glasgow, Glasgow, G75 0QF, United Kingdom
| | - Jordan Thompson
- Institute of Aquaculture, University of Stirling, Stirling, FK94LA, United Kingdom
| | - James Fennell
- Institute of Aquaculture, University of Stirling, Stirling, FK94LA, United Kingdom
| | - Susan Fitzer
- Institute of Aquaculture, University of Stirling, Stirling, FK94LA, United Kingdom.
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