Browsing by Subject "Fish distribution"

Now showing 1 - 1 of 1

From somatic growth to community structure of marine fishes : explaining variation with physical drivers and methodological biases at multiple scales
(2021-04-28) Bolser, Derek Gordon; Erisman, Brad E.; Esbaugh, Andrew; Fuiman, Lee; Grüss, Arnaud; Holt, Joan
The life history traits, population dynamics, and community ecology of marine fishes vary along spatio-temporal gradients in environmental conditions and habitat (i.e. physical conditions). Accordingly, incorporating physical drivers into fisheries assessments can improve fishery management advice, and thus the sustainability of fisheries. However, collective inferences on the effects that physical conditions have on fishes can be difficult to draw due to confounding effects of scale, sampling procedure, gear type, and other aspects of methodology. Here, I examined the role of physical drivers and methodological biases in explaining variation in aspects of fish populations and communities across levels of biotic organization. In the first study contained in this dissertation, I employed simulations to demonstrate the influence of sample distribution on growth parameter estimates and per-recruit assessment for the Gulf Corvina (Cynoscion othonopterus) in the Gulf of California. Sample distribution could confound growth parameter estimates in conventional assessments, and is especially important to account for when documenting spatio-temporal variation in growth, as sample distributions are rarely consistent over time and space. In the second, I described the effects – or lack thereof – of physical conditions on the distributions of common petroleum platform-associated fish species in the Gulf of Mexico through large-scale submersible camera sampling. In the third, I combined camera and hydroacoustic data to characterize water-column fish communities at petroleum platforms and identified the dominant physical drivers that shape them. In the fourth, I examined the challenges of assessing fish community size spectra with hydroacoustics in rugose marine habitats. Assessing the size spectra of fish communities over time and space is useful for understanding the effects of physical conditions and anthropogenic activities on community structure, and using hydroacoustic technology allows size spectra to be assessed more rapidly and efficiently than conventional methods. The findings and approaches described in this dissertation may be used to understand variation in fish growth, distribution, abundance, and community structure in response to physical drivers, thereby making spatial and ecosystem considerations more accessible to fisheries assessment and management frameworks