Cluster Sampling: A Pervasive, Yet Little Recognized Survey Design in Fisheries Research

Nelson, Gary A.

doi:10.1080/00028487.2014.901252

Cited by 37 publications

(19 citation statements)

References 36 publications

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“…Models that were assumed to follow a Poisson distribution were evaluated with deviance/df, and models that were assumed to follow a binomial distribution were evaluated with the Hosmer–Lemeshow test. Individual platforms were treated as clusters to account for sampling the same platform multiple times (Nelson ), and platform was the experimental unit. An alpha of 0.05 was used, and the reported measure of dispersion was 1 SD unless otherwise noted.…”

Section: Methodsmentioning

confidence: 99%

Sheepshead Foraging Patterns at Oil and Gas Platforms in the Northern Gulf of Mexico

Reeves

Chesney

Munnelly

et al. 2018

N American J Fish Manag

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In the northern Gulf of Mexico, there are over 2,000 oil and gas platforms (hereafter, "platforms") that are de facto artificial reefs. The ecological importance of platforms is the subject of debate, but little information exists on the extent to which fish feed on platform-dwelling benthic organisms. We used a camera array to characterize the frequency and duration of incidents in which Sheepshead Archosargus probatocephalus foraged on platformdwelling benthic organisms. We also characterized abundances and distributions of select platform-dwelling benthic organisms (barnacles, blennies, and stone crabs). Sheepshead foraging was more strongly associated with dissolved oxygen (DO, mg/L; measured at each camera) and time to slack tide (high or low) than other biological (prey densities), physiochemical, locational, or temporal variables. The number of Sheepshead foraging incidents increased by 18.9 incidents·m −2 ·h −1 (95% confidence interval [CI] = 4.6-33.3) when DO increased by 1.0 mg/L; foraging incidents increased by 4.5 incidents·m −2 ·h −1 (95% CI = 1.6-7.4) when time to slack tide increased by 1.0 h. The time Sheepshead spent foraging increased by 245.4 s·m −2 ·h −1 ( 95% CI = 144.1-346.7) when DO increased by 1.0 mg/L, and time spent foraging increased by 78.0 s·m −2 ·h −1 (95% CI = 60.5-95.5) when time to slack tide increased by 1.0 h. Abundances of barnacles and blennies decreased with increasing depth. The presence of hypoxia near the seafloor during the late summer appeared to cause barnacle mortality, which shifted barnacle depth distributions upward (i.e., 1-3 m shallower). Platform-dwelling benthic organisms persisted throughout the hypoxia season and served as prey for Sheepshead.

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Section: Methodsmentioning

confidence: 99%

Sheepshead Foraging Patterns at Oil and Gas Platforms in the Northern Gulf of Mexico

Reeves

Chesney

Munnelly

et al. 2018

N American J Fish Manag

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“…The probability of postrelease mortality was modeled using mixed-effects logistic regression models (Bolker et al 2009). A random intercept was specified for each gang because fish captured together in space and time were not independent (Nelson 2014). Based on previous field observations, we constructed 26 plausible, a priori candidate models by using combinations of deep-release treatment, gill-net trauma condition, barotrauma condition, fish length, and interactions between length and the other three covariates.…”

Section: Methodsmentioning

confidence: 99%

Effects of Gill-Net Trauma, Barotrauma, and Deep Release on Postrelease Mortality of Lake Trout

Fredericks

Quist

2015

Journal of Fish and Wildlife Management

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Unaccounted postrelease mortality violates assumptions of many fisheries studies, thereby biasing parameter estimates and reducing efficiency. We evaluated effects of gill-net trauma, barotrauma, and deep-release treatment on postrelease mortality of lake trout Salvelinus namaycush. Lake trout were captured at depths up to 65 m with gill nets in Priest Lake, Idaho, and held in a large enclosure for 10–12 d. Postrelease mortality was the same for surface-release–and deep-release–treated fish (41%). Mixed-effects logistic regression models were used to evaluate effects of intrinsic and environmental factors on the probability of mortality. Presence of gill-net trauma and degree of barotrauma were associated with increased probability of postrelease mortality. Smaller fish were also more likely to suffer postrelease mortality. On average, deep-release treatment did not reduce postrelease mortality, but effectiveness of treatment increased with fish length. Of the environmental factors evaluated, only elapsed time between lifting the first and last anchors of a gill-net gang (i.e., lift time) was significantly related to postrelease mortality. Longer lift times, which may allow ascending lake trout to acclimate to depressurization, were associated with lower postrelease mortality rates. Our study suggests that postrelease mortality may be higher than previously assumed for lake trout because mortality continues after 48 h. In future studies, postrelease mortality could be reduced by increasing gill-net lift times and increasing mesh size used to increase length of fish captured.

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“…Thus, all crabs collected from an individual platform constituted an individual cluster for population comparisons, and the two density estimates at an individual platform constituted a cluster for comparisons of densities. This prevented falsely inflating the degrees of freedom (i.e., pseudoreplication : Hurlbert 1984) and also accounted for the correlation between crabs or density estimates from the same platform (Nelson 2014). We controlled for nonindependence of density estimates and crabs from the same platform by using random effects in all ANOVA (Laird and Ware 1982) and treating platforms as clusters in the logistic regression (Stiratelli et al 1984;Zeger and Karim 1991) and proportional odds model (Hartzel et al 2001).…”

Section: Stone Crabs On Louisiana's Nearshore Platformsmentioning

confidence: 99%

Stone CrabMenippespp. Populations on Louisiana's Nearshore Oil and Gas Platforms: Higher Density and Size at Maturity on a Sand Shoal

et al. 2017

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Oil and gas platforms are common in the northern Gulf of Mexico. Platforms provide substrate for sessile organisms such as barnacles and oysters that enhance habitat for stone crabs Menippe spp. and other foulingassociated organisms. In recent years, Louisiana's small nearshore platforms (<15 m) have been subjected to a high rate of removal, but little is known about their relative value as artificial reefs. During 2014, we compared stone crab populations at platforms on and off Ship Shoal in order to evaluate habitat conditions in the two areas. We hypothesized that platforms on the shoal would provide higher quality habitat than those in the surrounding area because the shoal supports higher diversity and abundances of benthic organisms. Stone crab populations were characterized by means of visual counts and by removing subsamples for species identification, sexing, and carapace measurements. Of the 378 stone crabs collected, 368 were Gulf stone crabs M. adina and 10 were Cuban stone crabs M. nodifrons. Stone crabs colonized every platform studied, but densities were higher (mean values: 4.0 crabs/m 2 on the shoal versus 1.8 crabs/m 2 off the shoal), and carapace width at 50% maturity (CW50) was 27.1 mm larger for crabs on than off the shoal. Mean carapace width, size-class distribution, and sex ratio of crabs on and off the shoal were not significantly different. Platforms provided substrate for barnacles, which enhanced the structural complexity of platforms and were observed to be prey for stone crabs. Nevertheless, higher stone crab density and CW50 on the shoal suggested that shoal platforms are better habitat types for stone crabs. The Mississippi River watershed drains 41% of the contiguous United States (Milliman and Meade 1983; Turner and Rabalais 1991) and discharges into the northern Gulf of Mexico (nGOM) where it forms vast coastal wetlands, and

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Cluster Sampling: A Pervasive, Yet Little Recognized Survey Design in Fisheries Research

Cited by 37 publications

References 36 publications

Sheepshead Foraging Patterns at Oil and Gas Platforms in the Northern Gulf of Mexico

Sheepshead Foraging Patterns at Oil and Gas Platforms in the Northern Gulf of Mexico

Effects of Gill-Net Trauma, Barotrauma, and Deep Release on Postrelease Mortality of Lake Trout

Stone CrabMenippespp. Populations on Louisiana's Nearshore Oil and Gas Platforms: Higher Density and Size at Maturity on a Sand Shoal

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