The seasonal movement of sediment-associated marine-derived nutrients in a morphologically diverse riverbed: the influence of salmon in an Interior British Columbia river.

Autor: Rasmus KA; Ministry of Environment and Climate Change Strategy, 3726 Alfred Street, Smithers, BC V0J 2N0 Canada., Petticrew EL; Department of Geography, Earth and Environmental Sciences, University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 Canada., Rex J; Ministry of Forests Omineca Region, Research and Forest Health, 5th Flr. 499 George St., Prince George, BC V2L 1R5 Canada.
Jazyk: angličtina
Zdroj: Journal of soils and sediments [J Soils Sediments] 2023; Vol. 23 (10), pp. 3638-3657. Date of Electronic Publication: 2023 Jun 21.
DOI: 10.1007/s11368-023-03563-2
Abstrakt: Purpose: This study (1) investigated the extent to which flocculation and the hydrological and morphological attributes of an interior salmon-bearing river regulate the seasonal storage of marine-derived nutrients (MDN) and (2) compared the contribution of MDN to the fine bed sediment relative to other nutrient sources to the river.
Methods: Previous research has determined that the co-existence of re-suspended fine sediment, generated by salmon redd construction, with salmonid excretion and decay products in the water column creates ideal conditions for the flocculation of these inorganic and organic particles. Stored and suspended fine bed sediment was sampled from seven sites with varying morphologies and bed substrate down the length of a large spawning river in the interior of British Columbia over a 12-month period. MDN contributions to the sediment was tracked using aggregated versus dispersed particle size, carbon-to-nitrogen ratios, stable carbon and nitrogen isotopes, and MixSIAR modeling.
Results and Discussion: (1) There was a significant longitudinal spatial distinction of nutrient retention between sites upstream and downstream of a large seasonally inundated floodplain; (2) the MDN isotopic signal in the surficial stored bed sediment in this sample year was short term; and (3) upstream spawner numbers, substrate size, stream morphology, and discharge were relevant to both the magnitude and retention time of sediment-associated MDN.
Conclusion: A cumulative magnification of MDN was correlated with the distance from the headwaters and the number of upstream spawners. The relationship between MDN retention in interior rivers, and possible multi-year accumulation, was influenced by variability in channel morphology, substrate size, and the presence of an inundated floodplain halfway down the river.
Competing Interests: Conflict of interestThe authors declare no competing interests.
(© Crown 2023.)
Databáze: MEDLINE
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