Hypoxia augments edge effects of water column stratification on fish distribution

Derek W. Chamberlin; Carey Knight; Richard Kraus; Ann Marie Gorman; Wenzhao Xu; Paris D. Collingsworth

doi:10.1016/j.fishres.2020.105684

Home/Archive/USGS

USGS · 70211181

Hypoxia augments edge effects of water column stratification on fish distribution

Derek W. Chamberlin·Carey Knight·Richard Kraus·Ann Marie Gorman·Wenzhao Xu·Paris D. Collingsworth

View original source ↗Export metadata ↓

Abstract

Hypoxic conditions in both freshwater and marine habitats have a significant effect on the distribution of fish in the water column, resulting in some fishes aggregating near the edges of the hypoxic zone. These aggregations may increase fish susceptibility to fishing gears, with attendant effects on stock assessment inferences. We investigated how hypoxic conditions influenced catch rates of yellow perch ( Perca flavescens ) in both fishery independent bottom trawls and stationary commercial trap nets. Specifically, we examined how the presence of hypoxia affected trap net catch rates and how hypoxia interacted with hypolimnion thickness to modify trawl catch rates. Bottom trawl catch rates were significantly higher in hypoxic conditions than in normoxic conditions, and in each of these scenarios catch rates declined as hypolimnion thickness increased. By comparison, trap net catch rates had a dome-shaped response to the duration of hypoxia with the highest catch rates occurring at intermediate levels. Increased catch rates in hypoxic conditions potentially causes yellow perch population models, which rely on both trap net and trawl indices, to overestimate abundance and could result in overfishing.

Explore related subjects

Fisheries Research Article

Source-reported bounding extent: 41.31082388091818° to 43.11702412135048° latitude; -83.49609375° to -78.59619140625° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Derek W. Chamberlin, Carey Knight, Richard Kraus, Ann Marie Gorman, Wenzhao Xu, Paris D. Collingsworth. 2020. Hypoxia augments edge effects of water column stratification on fish distribution. https://doi.org/10.1016/j.fishres.2020.105684

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Abundance estimates for a remnant population of extirpated Lake Erie cisco Coregonus artedi (albus) in Crystal Lake, Pennsylvania

The discovery of a remnant Lake Erie cisco ( Coregonus artedi “ albus ”) population in Crystal Lake, Pennsylvania provides a unique opportunity to evaluate the status of a fish that was extirpated, with the possibility that the unique Lake Erie form was extinct. Historically, Lake Erie cisco supported the largest freshwater fishery in the world, with annual harvests exceeding 22 million kilograms — nearly equivalent to the contemporary commercial harvest of all fish species in all of the Great Lakes, combined. The loss of the ecologically and economically important albus cisco has been a major impediment to restoring native coregonine diversity and food-web function in Lake Erie. To assess this remnant population, we integrated nighttime split-beam hydroacoustic surveys with daytime remotely operated vehicle (ROV) videography during stratification to estimate abundance and characterize habitat use by cisco. Hydroacoustic detections were restricted to an oxythermal habitat band suitable for cold-water fishes and filtered to include target strengths consistent with age-2 + cisco and lake trout, while ROV footage provided species-level confirmation and informed apportionment of acoustic targets. Cold-water fishes were confined to the metalimnion and occurred at low but measurable densities. Based on combined acoustic and visual information, mean age-2 + cisco abundance was estimated at N = 815. Biomass estimates were similar to estimates from other self-sustaining inland lake populations. The presence of multiple year classes and older fish indicated high survival and ongoing recruitment. These results provided the first quantitative estimates of the only known population of Lake Erie “albus” cisco and suggests that Crystal Lake supports a viable source population for restoration efforts.

Pennsylvania↗

USGS2026

Using a temporary emigration model to estimate abundance of stream fishes from hybrid removal surveys with and without block nets

Monitoring programs are often faced with a decision to allocate resources into either robust spatiotemporal coverage to estimate a population index (e.g., not true abundance) or confirming closed sampling conditions (e.g., with block nets) for an unbiased population estimate at the cost of spatiotemporal coverage. However, making accurate and precise abundance estimates at robust spatiotemporal scales is possible when combining open and closed sampling designs with integrated modeling techniques. We used simulations and a case study of backpack electrofishing surveys in the Santa Ana River, California to test the efficacy of an integrated abundance model (temporary emigration model, TE) to estimate abundance of fishes using removal sampling methods with a hybrid sampling design (sampling with and without block nets during removal sampling). We found that the TE model performed well under most modeling scenarios (sample size, amount of closure violation, number of samples collected during closure), although at least a few samples with block nets were necessary for all parameters to be estimable. When applied to fish surveys in the Santa Ana River, we found that catch of the fishes fit to the TE model (Santa Ana Sucker, Arroyo Chub, Channel Catfish, Largemouth Bass, Yellow Bullhead) showed little evidence that the closure assumption was violated when block nets were not used. Additionally, we found that the abundance of non-native fishes negatively affected the abundance of the native Santa Ana Sucker, which was also found to adversely affect the native fish’s access to critical habitat consisting of gravel and cobble substrate. Our results indicate that the TE model presents a viable solution to common sampling problems that impact many monitoring programs, where precise and accurate population estimates can be made at large spatiotemporal scales even when most samples violate the closure assumption.

California↗

USGS2026

Strength of depensation not influenced by fish population productivity

A long-held assumption in the management of exploited fisheries is that fish populations will compensate with increased recruit survival to replenish the population when adult stock size is reduced through harvest. Observations of depensatory recruitment (reduced recruit survival at low adult stock size) and critical depensatory thresholds have challenged the compensation assumption. Post et al. (2002) postulated that critical depensatory thresholds were related to fish population productivity. Walleye Sander vitreus are a culturally, economically, and recreationally important sportfish whose persistence is being challenged by natural recruitment declines throughout much of its native range. Depensation, among other abiotic and biotic stressors, has been implicated in walleye natural recruitment declines. If walleye population productivity is related to critical depensatory thresholds, then population productivity benchmarks could be established to reduce the probability of crossing them. We used empirically-derived and model predicted depensation values ( q ) and empirical estimates of walleye population productivity to test for relationships between these variables in northern Wisconsin lakes. We found little evidence for a relationship between q and walleye population productivity across all lakes examined. Our finding failed to support the theoretical postulation of a relationship between these variables by Post et al. (2002) for walleye. Little evidence for a relationship between q and population productivity suggests that depensatory thresholds may differ among individual walleye populations and that walleye populations may transition abruptly between compensatory and depensatory states. Given our findings, conservation efforts for walleye that solely focus on low productivity populations may miss other trends because population productivity may not be considered a broad predictor of crossing a critical depensatory threshold.

Fisheries Research↗