Biology subjects

Tallman, R.

Publications and source records attributed to Tallman, R..

2 recordsLinked to original sources

bioRxiv2025

Conservation units for anadromous Arctic Char (Salvelinus alpinus) in the Canadian Arctic informed by genetic structure, population connectivity and adaptive genomic variation

Intraspecific genetic diversity is a crucial aspect of biodiversity conservation as it preserves evolutionary potential and enhances resilience to environmental change. Genomic-informed delineation of Conservation Units (CUs) offers ways of subdividing species into groups based on historical isolation and adaptive differentiation, to develop biologically relevant conservation and management policies. CUs have been defined in many species of harvested anadromous salmonids, but broad scale data remains lacking in the Canadian Arctic, where anadromous Arctic Char (Salvelinus alpinus) dominates catches in Indigenous-led subsistence and commercial fisheries. In this study, we use low-coverage whole-genome data from 30 Canadian populations of Arctic Char to define CUs based on population structure and connectivity, as well as adaptive genetic variation. We highlight two main genetic groups, each of which comprises three subgroups, or candidate CUs: the North (above the 67th parallel), including the North Baffin Island, Kitikmeot, and Inuvialuit Settlement Region CUs; and the South (below the 67th parallel), including the South Baffin Island, Ungava Bay, and Hudson Bay CUs. This delimitation is supported by areas of low effective migration between candidate CUs, as well as isolation-by-environment, which suggests adaptive differentiation. Finally, we discuss opportunities and caveats relating to linkage when identifying adaptive genetic variation from whole genome sequencing data through genome scans and Gene-Environment Associations.

evolutionary biology↗

bioRxiv2024

Does method of field preparation affect survival and growth of juvenile Chinook salmon in agricultural floodplains?

There is growing interest to integrate conservation initiatives into agricultural practices using a reconciliation ecology framework. In Californias Central Valley, one approach to improving crucial nursery habitat for threatened and endangered fish species is by re-creating floodplain habitats through the inundation of agricultural fields during the non-growing season. We conducted a series of field experiments in agricultural floodplains (winter-flooded rice fields that were once natural floodplains) to explore whether different field preparation methods enhanced growth and survival of floodplain-dependent fish species. Approximately 8,000 juvenile fall-run Chinook Salmon (Oncorhynchus tshawytscha) were reared for at least 28 days on eight, 0.2 ha experimental fields. Each experimental field represented one of four treatments (two replicates per treatment): addition of large wood, addition of in-field canals, addition of both large wood and in-field canals, and control-where no additional field preparations were implemented beyond standard post-growing practices: i.e., chopping rice into stubble, baling and removing excess rice straw, and discing the field with a single pass by plowing rice straw into the ground to promote decomposition. We found no significant difference in water temperature, fish growth or fish survival among habitat treatments. Across treatments, survival ranged from 50.1%-78.3% and averaged 65.75% (/- 7.89% SE). These findings suggest agricultural floodplains require no additional modifications to promote fish growth and survival. Results illustrate the benefits of integrating working landscapes with conservation initiatives by creating more accessible and beneficial habitat for native fishes.

ecology↗