Spatial structure of large‐river fish populations across main‐stem and tributary habitats

Abstract

The spatial variability in demographic parameters represents fundamental information for conservation and management of large-river fish populations. We assessed demographic processes including survival and movement across macroscale habitats in a large-river network using 2 candidate large-river species with contrasting life history strategies. We used mark-recapture data and a multistate model framework to estimate survival and transition probabilities between main-stem and tributary habitats for both channel catfish and shovelnose sturgeon. Annual survival for channel catfish was similar in main-stem and tributary habitats (range in S = 0.47-0.58). Annual survival for shovelnose sturgeon was less in the tributary (S = 0.68) compared with the main stem (S = 0.83). The probability of movement among macroscale habitats differed between species. However, the greatest probability of movement occurred from the tributary to the main-stem for both channel catfish (ψ = 0.42) and shovelnose sturgeon (ψ = 0.27). Movement between main-stem and tributary rivers may be a prominent characteristic for both channel catfish and shovelnose sturgeon and could influence population demographic rates and abundance across systems. Riverine fish populations are likely structured across multiple salient scales-including tributary and main-stem habitats. Consideration of connectivity across tributary and main-stem habitats with respect to species' life history strategy and life stage may better integrate a systems' perspective for conservation and management of largeriver fish populations.

Prioritizing native migratory fish passage restoration while limiting the spread of invasive species: A case study in the Upper Mississippi River

“…These results indicate the value of reestablishing connectivity to major tributaries of the UMR and are supported by studies demonstrating the importance of tributaries in maintaining fish biodiversity within large river systems (Pracheil et al, 2013). This habitat connectivity is particularly important for migratory fishes, which often require access to habitat not only along river mainstems but also their tributaries, which provide important areas for recruitment (Pracheil et al, 2009;Spurgeon et al, 2018) and can provide important conservation targets for restoring habitat connectivity (Pracheil et al, 2019).…”

Tag Type and Location‐Dependent Retention Impart Varied Levels of Bias on Mark–Recapture Parameter Estimates

“…Mark–recapture is an important technique in fisheries management that provides quantitative estimates of fish population characteristics and dynamics, including abundance, growth, and survival (Quinn and Peterson 1996; Edwards et al 1997). When combined with spatial information, recaptures of tagged individuals offer insight into the movement of individuals and population connectivity (Spurgeon et al 2018). Mark–recapture studies typically require fisheries professionals to attach or insert tags in different anatomical locations (hereafter, “locations”; e.g., jaws, opercula, or dorsal musculature) under varying study designs (e.g., open or closed designs; Pine et al 2012).…”

Blue catfish population characteristics and dispersal along a Great Plains river gradient

“…The similarities observed in population characteristics, movement, and environmental history of Blue Catfish occupying river reaches below Bowersock Dam coupled with the limited, unidirectional connectivity this dam creates, supports differential management for Blue Catfish populations separated by this barrier. Effective management strategies below Bowersock dam would reflect those of other mobile, large‐river fishes; adopting a spatial scale reflecting the species' use of a complex river network (Pracheil et al, 2012; Spurgeon, Pegg, Hamel, & Steffensen, 2018; Tripp et al, 2019) and utilizing interjurisdictional collaboration across the defined river network to achieve management objectives (Koehn, 2015; Pope et al, 2016; Siddons et al, 2017). Applying this approach to other systems offers the flexibility required to achieve both trophy‐based objectives within Blue Catfish native range as well as population control and mitigation in non‐native watersheds.…”