<p>White croaker (<i>Genyonemus lineatus</i> family: Sciaenidae) are a benthic foraging fish associated with soft sediment and wastewater outfalls in Southern California. While they are used as a sentinel species due to their high organochlorine contaminant loads, little is known of their movements in relation to contaminated habitats. Acoustic telemetry was used to characterize the site fidelity, area use, and dispersal of 97 white croaker on the Palos Verdes Shelf, California. White croaker demonstrated generally low, but highly variable residency and recurrence to the Palos Verdes Shelf and exhibit nomadic movement patterns. Although the entire monitored shelf was visited by white croaker, habitats in proximity to wastewater outfalls and between 25&ndash;35 m depth were preferentially used. Approximately half of white croaker migrated into Los Angeles Harbor. These data are vital for understanding organochlorine contaminant exposure for planning future remediation and monitoring. </p>

<p> Between August 2010 and September 2012, acoustic telemetry was used to monitor movements of 31 Yellow Snapper and 25 Leopard Grouper at Los Islotes reserve, a small rocky reef and reported spawning site for both species in the southwest Gulf of California. Overall, both species exhibited site fidelity to Los Islotes (grouper: present 64 f 30% of days; snapper: 49 &plusmn; 30%). Both species frequented rock and wall habitats; though snapper showed greater site attachment to specific portions of the reserve, grouper exhibited greater site fidelity to the entire reserve. Approximately 30% of snapper showed indications of spawning-related migrations elsewhere in the Gulf, though no clear seasonal pattern of migration was found for grouper. The limited degree of spawning-related emigration and moderate-high levels of site fidelity indicate that if properly placed, small reserves such as Los Islotes may yet adequately protect small, resident populations of snapper and grouper.</p>

<p> Fish passage success rates through hydraulic infrastructure have been historically low due to flow field conditions that exceed the physical or behavioral capabilities of a given species. Significant efforts to design and modify hydraulic structures for enhanced passage rates have failed to achieve the desired results, with a primary reason being a poor understanding of how fish respond to complex hydraulic conditions. Many contemporary research efforts have targeted the inter-relationship between hydraulics and fish behavior in the laboratory using live fish trials in an attempt to better comprehend these interactions and ultimately provide a basis for the development of biologically-based design criteria. In this study experiments were conducted to assess the behavioral responses along swimming trajectories of western blacknose dace (<i> Rhinichthys obtusus</i>) in turbulent flow conditions. The objective was to test the hypothesis that the dace would preferentially adjust their swim paths to minimize their exposure to elevated turbulent conditions. Experimental data were collected through digital imaging of dace trajectories for fish that had been released into a shallow flume and allowed to swim through turbulence enhanced flow fields. Additionally, detailed velocity measurements were collected with an acoustic Doppler velocimeter to allow the comparison of dace trajectories to flow field conditions represented by average metrics of turbulent kinetic energy and Reynolds shear stresses. Analysis of the data consisted of the quantification of the proportion of the time that a dace's swim path selected a direction toward a lower magnitude turbulence condition when such an option existed. Fish paths were also graphically compared to turbulence contour plots to qualitatively assess the presence of swim path preferences or patterns. Lastly, video footage of each trial was evaluated to qualitatively assess the presence of novel behaviors that could have implications for the swimming trajectories observed. Results indicate that the dace did not preferentially avoid turbulence at statistically significant levels under the conditions experienced in the flume; however, data do suggest that some behavior relative to turbulence was non-random. Qualitative observations of video footage suggest that non-hydraulic factors, such as the presence of conspecifics and light intensity, also influence the swim path trajectories of the western blacknose dace. Future research will require more targeted turbulent conditions, simultaneous multivariate observations and analyses that factor in non-hydraulically-based behavior and the incorporation of coupled behavioral and hydraulic data at reduced time and length scales for primary variables. It is envisioned that the results of this study can provide guidance for future studies aimed at developing biologically based design criteria for enhanced fish passage at hydraulic infrastructure.</p>

<p> The widespread introduction of round goby (<i>Neogobius melanostomus </i>) throughout the Great Lakes basin has raised concerns regarding increased risk of egg predation on nesting fish species. Five-minute observation trials were conducted to determine the identity and number of nest predators on rock bass (<i>Ambloplites rupestris</i>), pumpkinseed (<i>Lepomis gibbosus</i>), and smallmouth bass (<i>Micropterus dolomieu</i>) nests following removal of the guarding male. Rock bass had a greater proportion of nests invaded (85.4 %) and average number of predators per nest (9.32, SE 1.7) than pumpkinseed (45.0%, 1.83, SE 0.64) in 2011. Similarly, rock bass had a greater proportion of nests invaded (52.5%) and average number of predators per nest (5.3, SE 1.7) than pumpkinseed (35.0%, 2.3, SE 1.1) and smallmouth bass (37.5%, 2.7, SE 0.94) in 2012. Principal components analysis and canonical correspondence analysis of habitat variables indicates some species are more vulnerable to nest predation due to preferred spawning habitat. </p>

Performative Landscapes examines and strategizes the production of artificial wetlands, port facilities, and recreational/commercial fishing areas by utilizing the excess dredge material generated by the Houston Ship Channel. Performative Landscapes seeks to propose a developmental tool kit and set of logics that will guide the growth of new wetlands and foster the production of integrated, not fragmented, program along Galveston Bay. The primary goal of the project then is to produce a design method, a generative seed, that can be used in the genesis of new and integrated man-made and natural systems along the coast, and in Galveston Bay. What I primarily advance in this thesis is a design analytic and a design method geared towards ecological and relational thinking. These two tools are derived and inspired by the concept of self-organization in material systems and the operational searching method of the genetic algorithm as defined by David E. Goldberg.

<p> The objectives of this study were to measure injuries and impairments directly observed from gags <i>Mycteroperca microlepis</i> caught and released within a large-scale recreational fishery, develop methods that may be used to rapidly assess the condition of reef fish discards, and estimate the total portion of discards in the fishery that suffer latent mortality. Fishery observers were placed on for-hire charter and headboat vessels operating in the Gulf of Mexico from June 2009 through December 2012 to directly observe reef fishes as they were caught by recreational anglers fishing with hook-and-line gear. Fish that were not retained by anglers were inspected and marked with conventional tags prior to release. Fish were released in multiple regions over a large geographic area throughout the year and over multiple years. The majority of recaptured fish were reported by recreational and commercial fishers, and fishing effort fluctuated both spatially and temporally over the course of this study in response to changes in recreational harvest restrictions and the Deepwater Horizon oil spill. Therefore, it could not be assumed that encounter probabilities were equal for all individual tagged fish in the population. Fish size and capture depth when fish were initially caught-and-released also varied among individuals in the study and potentially influenced recapture reporting probabilities. The Cox proportional hazards regression model was used to control for potential covariates on both the occurrence and timing of recapture reporting events so that relative survival among fish released in various conditions could be compared. A total of 3,954 gags were observed in this study, and the majority (77.26%) were released in good condition (condition category 1), defined as fish that immediately submerged without assistance from venting and had not suffered internal injuries from embedded hooks or visible damage to the gills. However, compared to gags caught in shallower depths, a greater proportion of gags caught and released from depths deeper than 30 meters were in fair or poor condition. Relative survival was significantly reduced (alpha <u>&lt;</u>0.05) for gags released in fair and poor condition after controlling for variable mark-recapture reporting rates for different sized discards among regions and across months and years when individual fish were initially captured, tagged and released. Gags released within the recreational fishery in fair and poor condition were 66.4% (95% C.I. 46.9 to 94.0%) and 50.6% (26.2 to 97.8%) as likely to be recaptured, respectively, as gags released in good condition. Overall discard mortality was calculated for gags released in all condition categories at ten meter depth intervals. There was a significant linear increase in estimated mortality from less than 15% (range of uncertainty, 0.1-25.2%) in shallow depths up to 30 meters, to 35.6% (5.6-55.7%) at depths greater than 70 meters (p &lt; 0.001, R² = 0.917). This analysis demonstrated the utility of the proportional hazards regression model for controlling for potential covariates on both the occurrence and timing of recapture events in a large-scale mark-recapture study and for detecting significant differences in the relative survival of fish released in various conditions measured under highly variable conditions within a large-scale fishery.</p>

No description available.

<p> Marine Protected Areas (MPAs) are successful place-based management tools in protecting Essential Fish Habitat (EFH) from commercial and recreational fishing pressures. In the southeast Atlantic, the morphometric environment of the seafloor has been found to be a control on Essential Fish Habitat (EFH) (Sedberry and Van Dolah 1984). To this end, modern methods of acoustic data acquisition and morphometric analysis of the seascape are promising oceanographic techniques for identifying and delineating EFH. In July, 2013, the NOAA Ship Pisces collected bathymetric, backscatter and water column data for potential habitat sites along the U.S. Southeast Atlantic continental shelf. A total of 205 km² of seafloor were mapped between Mayport, FL and Wilmington, NC, using the SIMRAD ME70 multibeam echosounder system. In addition, a total of <i>n</i> = 7410 fish presences were recorded within the water column, using the SIMRAD EK 60 split-beam echosounder system. These data were processed in CARIS HIPS, QPS Fledermaus, MATLAB and Echoview. This study provides a morphometric characterization and quantitative assessment of fish present within each survey site and identifies features of the bathymetry that help explain the presence of demersal fish. A total of 106 unique maps were created, illustrating seafloor morphometrics and fish distributions across the seascape. In ArcGIS, 14 morphometrics were generated as candidate explanatory variables for fish abundances in small (5-12 cm), medium (12-29 cm) and large (>29 cm) size classes. We explored fish-seascape interactions at two spatial scales in the GIS using a site-wide and 50 x 50 m grid scale. At the site- wide scale, <i>X&macr;</i> Slope (R² = 0.97), <i> X&macr;</i> Slope of Slope (R² = 0.90) and &sigma; Depth (R² = 0.87) provided the strongest explanatory power in a bivariate analysis and may be used to help identify EFH at a coarse scale. At a 50 x 50 m grid scale, <i>X&macr;</i> Slope, <i>X&macr;</i> Slope of Slope and <i>X&macr;</i> Backscatter emerged as the strongest contributing variables, when combined in a multivariate analysis. Overall, multivariate model R² values were low and not predictive, but allow for the identification of variables contributing to the characterization of fish-seascape interactions at a finer scale.</p>

<p>The Pacific Coastal ecoregion contains large tracts of economically important forestlands that also serve as critical stream habitat for endangered Salmonids. Excessive fine sediment deposition in streams of this region is a major environmental concern in the region but difficult to measure directly. The use of stream invertebrates to monitor fine sediment conditions in streams requires careful consideration of several important factors that complicate their use as bioindicators including high spatial and temporal variability and covariance with other environmental variables. </p><p> To evaluate the use of stream invertebrates as bioindicators of excessive fine sediment, three hypotheses were tested. The first hypothesis was that invertebrates would be related to broad-scale climate variables (Chapter 2). The second hypothesis was that functional aspects of the invertebrate community would serve as useful indicators of excessive fine sediment condition. (Chapter 3). The third hypothesis was that invertebrates in streams with naturally high levels of sediment would be tolerant to fine sediment (&lt;2 mm, Chapter 4). Hypotheses were tested using a temporal data set at two streams in western Oregon, spatial data from 214 sites across the Oregon Coast Range, and <i> in-situ</i> experiment conducted in streams with erosive or resistant geologies. </p><p> In the temporal study, both invertebrate density and functional traits were positively related to El Ni&ntilde;o strength (R² range = 0.22&ndash;0.36, &rho; range = 0.008&ndash;0.04) and air temperature (R² range = 0.32&ndash;0.49, &rho; range = 0.002&ndash;0.01). The spatial study identified several environmental and hydrological factors that exhibited strong negative controls on both fine sediment (Mantel r range 0.14&ndash;0.25, &rho; range = 0.001&ndash;0.01) and invertebrate Scrapers (R² range = 0.11&ndash;0.14, &rho; range = 0.001&ndash;0.04). The result of the experimental study provide evidence that invertebrates in streams with erosive geologies exhibit tolerance to sediment addition when compared to invertebrates in resistant geologies (mean loss=15%, &rho; &lt;0.01) and that invertebrate grazing traits were most strongly associated with fine sediment dosing frequency (&rho; &lt;0.05). </p><p> The findings of this research demonstrate the role of geology in shaping invertebrate communities and their functional response to fine sediment addition and identify functional indicators that may be useful in different geologic settings. For environmental managers in the Pacific Coastal ecoregion, these findings are of potential value in assisting with the identification of biologically-relevant changes in stream fine sediment conditions and support efforts to balance economic needs in the region while protecting critical Salmonid habitat. </p>

<p> Although dawn and dusk periods comprise a relatively small part of the day, their importance as key ecological transition periods has been recognized for some time. Previous marine investigations into this transition have focused on tropical locations and have mostly been qualitative in nature. This project focused on the dusk period in sub-tropical reef fish communities off the coasts of North and South Carolina. High-definition underwater video was collected in 2013 and 2014 at a variety of sites featuring natural live-bottom habitat. Independent samples (43 videos) were obtained on 17 sampling dates. Fishes were tallied by time relative to sunset (TRTS) in an effort to identify temporal abundance patterns and categorize taxa by temporal niche. Sufficient data were collected for statistical analysis of 27 taxa, representing 15 families. Analyses explored whether there was a relationship between time and abundance. Of the taxa analyzed, ten showed no temporal pattern during the dusk period, seven showed abundance peaks during dusk, and ten showed declines in abundance during dusk. Patterns were not always consistent within families. In particular, the Serranidae and Sparidae families featured a variety of patterns. Uncommon species and ephemeral behavioral events were also noted and described.</p>