Скачать с ютуб "Subterranean fauna and carbon reservoirs in a subterranean estuary" David Brankovitz(Pres 21:5ISAE) в хорошем качестве

"Subterranean fauna and carbon reservoirs in a subterranean estuary" David Brankovitz(Pres 21:5ISAE)

This presentation was a part of the 5th International Symposium on Anchialine Ecosystems (5ISAE), held in Kailua-Kona November 3-5, 2022, and was shared virtually. Presentation 21: "Radiocarbon ages of subterranean fauna and carbon reservoirs in a subterranean estuary ecosystem suggests rapid transfer of organic carbon into the food web through heterotrophic and chemoautotrophic pathways." (abbreviated version) Session 5: Europe - Earth Sciences Presentation Authors: David Brankovits (1,2), John W. Pohlman (3), Mark H. Garnett (4), Joshua F. Dean (5) Affiliation: (1) Water Research Institute (IRSA), National Research Council of Italy (CNR), Verbania, Italy; (2) Woods Hole Oceanographic Institution, Woods Hole, MA, USA; (3) U.S. Geological Survey, Woods Hole Coastal and Marine Science Center, Woods Hole, MA, USA; (4) NERC Radiocarbon Facility, East Kilbride, UK; (5) School of Environmental Sciences, University of Liverpool, Liverpool, UK Presentation Abstract: Microbial processing of methane and dissolved organic carbon (DOC), originating from overlying tropical soils, is the critical link for shuttling food and energy to higher trophic levels of the food web within the Yucatan Peninsula’s coastal aquifer in Mexico. To further constrain pathways and rates of organic matter transformations in this habitat, we collected samples for stable and radiocarbon isotopic analyses targeting the biotic and abiotic components of the carbon cycle. In the freshwater, modern radiocarbon (14C) ages for terrestrial-origin DOC and microbial methane suggests the carbon comprising these food resources transferred rapidly from plants at the land surface to the subterranean realm. By contrast, DOC in the deeper saline groundwater is drastically lower in concentration and substantially older (radiocarbon signature equates to 6010 ± 95 14C yrs), implying long-term storage and transport of marine-derived DOC in the saline portion of the aquifer. Based on these properties, organic matter from the saline groundwater is not expected to support the food web. However, stable and radiocarbon isotopic values of the resident fauna indicate that carbon substantially older than the terrestrial-origin DOC in the freshwater also accumulates in the biomass of subterranean fauna, presumably through an in-site chemoautotrophic process that assimilates older carbon in the groundwater. These findings demonstrate that important sources of nutrition for the food web are intimately linked to the overlying subaerial habitat through multiple biogeochemical pathways, including chemoautotrophic and heterotrophic microbial processes that recycle 14C-depleted carbon into the food web. Furthermore, this study has implications for carbon turnover and organic matter transformation before the discharge of dissolved constituents with groundwater from the aquifer into the coastal sea.