This research provides a comprehensive picture of the economic status of the U.S. catfish industry through investigating several critical economic aspects such as technological progress, functional production relationships in intensive systems, regulatory costs, and economic contribution of the industry. The use of primary data is a unique aspect of this work reflecting the economic realities of catfish farms. Primary data collected through extensive in-person farm surveys covered over two-thirds of the catfish production areas in the U.S. The results of the study provided evidence of intensification in the U.S. catfish industry through increased adoption of two relatively new alternative production systems viz; intensively aerated ponds (6,315 ha) and split ponds (1,176 ha). The use of complementary technologies such as hybrid catfish on 53% of the catfish producing area and increased fixed-paddlewheel aeration rate of over 7.8 kW/ha also provided proof of technological progress on U.S. catfish farms. This study also identified critical factors contributing to productivity in increasingly adopted alternative production systems through two distinct production function models. Feed fed, as well as stocking biomass were found to be significant variables in both production functions. Results indicated further room for improvement in the use of inputs to increase production, especially in feed management. Along with identifying the nuances in the catfish industry, the study quantified regulatory costs on U.S. catfish farms at $45 million. Although faced with several hardships on the production front, the U.S. catfish industry contributes over $1.9 billion to the regional economy, supports more than 9,100 jobs, and generates over $78 million in tax revenues. The findings of the study serve a multitude of stakeholders including aquaculture farmers, researchers, Extension specialists, and policymakers who work towards improving the economic sustainability of the catfish industry as well as the U.S. aquaculture industry.

COMPARISONS OF FISH SPECIES INSIDE AND OUTSIDE OF MARINE PROTECTED AREAS OFF THE SOUTH CENTRAL COAST OF CALIFORNIA David E. Rasmussen From 2004-2008 and 2008-2009 Cal Poly University researchers conducted two separate tag and recapture studies of nearshore fish populations along California’s central coast. Three locations were sampled that have experienced different degrees of fishing pressure. Big Creek MPA has been closed to all fishing from 1993 onwards and is the farthest from port of all locations. Cambria lies closest to port of the three locations and because of this has the highest fishing pressure. Piedras Blancas lies midway between Cambria and Big Creek. Portions of Cambria and Piedras Blancas were designated as MPAs in 2007. Sampling protocols of these two different studies differed in bait used and size of commercial fish trap. An experiment was conducted to simultaneously compare the different trapping and baiting protocols from the prior studies to find a conversion factor that related catch per unit effort (CPUE), length frequency distributions and captured fish diversity between the two studies, thus providing a means to connect the two data sets for stock assessments and baseline MPA monitoring. Our sampling showed no significant difference in mean fish length or diversity between the two protocols for the five most common nearshore fish species captured, and three of the five species showed no significant difference in CPUE. Cabezon (Scorpaenichthys marmoratus), showed a significantly lower CPUE (50.5%) using the MLPA monitoring protocols compared to the commercial fishing protocol and black and yellow rockfish (Sebastes chrysomelas) had a significantly higher CPUE (310%) using the MLPA monitoring protocol. These findings provide a means of maintaining data continuity across the entire sample region and inclusion of earlier projects in the analyses of nearshore fish populations of the region. With the linkage of these two studies we provide important baseline data for the Cambria MPA from before it was established in 2007. Fish populations were compared on a year-to-year basis within each location, and between the different locations. I found several main factors helped to explain differences in size and abundance across time within individual locations, and across the three locations. These factors were inherent differences in habitat, establishment of MPAs, and changes in fishing pressure and post-larval recruitment. Cabezon were largest within Big Creek, followed by Piedras Blancas and Cambria which held the smallest fish, suggesting that fishing pressure is influencing fish size. However, cabezon were more abundant at Cambria than either other location suggesting that location is influencing abundance. Within Cambria, we are seeing an MPA effect with abundance within the MPA staying stable while the reference site is declining. Gopher rockfish (Sebastes carnatus) and black and yellow rockfish had similar trends with size and abundance between locations. Big Creek and Piedras Blancas held the largest fish, while Cambria was smaller. Both rockfish species were most abundant at Big Creek, followed by Cambria then Piedras Blancas. Size for these species is likely influenced by fishing pressure, and abundance is likely influenced by both fishing pressure and location. Both species increased in abundance 2004-2009 at Cambria, and this could be due to improved levels of post-larval recruitment. There is also a possible MPA effect for gopher rockfish at Cambria with a near significant divergence in size of fish between the MPA and reference site. Kelp greenling (Hexagrammos decagrammus) were similar in size and abundance between all sampling locations. There is a possible MPA effect at Cambria, with a significantly higher abundance than the reference site; however this difference predates the MPA’s establishment but could have been exacerbated by it. Lingcod (Ophiodon elongatus) size did not vary significantly between sites, but they were the most abundant at Cambria, followed by Piedras Blancas, then Big Creek, suggesting that habitat is influencing abundance. There was also a possible MPA effect on abundance of lingcod at Cambria with the MPA having a significantly higher abundance than the reference site. Similarly to the kelp greenling, these differences predated the MPA, but could have been exacerbated by its establishment, and abundance within the MPA has stayed stable, while the reference site was declining. Big Creek and Piedras Blancas have similar Shannon-Weiner diversity values, while Cambria has significantly lower. However, after MPA establishment at Cambria, the MPA has attained significantly higher diversity levels than the reference site. Over the short period of time that the Piedras Blancas and Cambria MPA have been established the populations within them have changed. However, there are no discernable trends in size, abundance and diversity between the MPA and reference sites at both locations. It is likely that with these slower growing, long-lived fish species that it will take more years for differences between the sites to manifest themselves.

Tomales Bay is situated in Marin County, about 40 miles north-west of San Francisco. This shallow bay averages about 1.5 miles in width and is about 12.6 miles in length, with an average depth of 12 feet (Johnson, Bryant and Hedgpeth, 1961). Oyster and herring comprise the main fishing industry, although the bay contributes a great amount of perch, smelt, halibut, and shark. Gill and seine nets are the most common gear used by fishermen. The primary objectives of this study were: (1) to determine the species composition of the bay, and the relation between seining success at different localities and such factors as tides and temperature; (2) to describe the life history of Phanerodon furcatus Girard, the most common perch of the bay.

Thais emarginata (Deshayes, 1839) and Thais canaliculata (Dulcos, 1832), are two common Pacific coast gastropods (Family: Muricidae). T. emarginata is found in semi-protected rocky areas from Alaska to Baja California, while T. canaliaulata occurs in quiet bays from Alaska to Monterey Bay, California (Ricketts and Calvin, 1966). Both species occur on rocks and jetties where they can be seen feeding upon barnacles and young mussels. Despite the abundance of these species their reproductive biology has not been examined. In the present study, the following aspects of the reproductive biology of T. emarginata and T. canalieulata are presented: Relationship of gonadal development to environmental factors; Histological changes in the reproductive organs during the gametogenic cycle; Spawning behavior; and Morphology of the egg capsules.

The world's biodiversity is concentrated in tropical ecosystems, yet tropical forests are being converted for agriculture at a rapid rate. I evaluated the potential of an alternative coffee production system known as Integrated Open Canopy (IOC) to contribute to avian conservation. This study was conducted from 2005-2010 in the Cordillera de Tilarán, Costa Rica. My results indicate that species richness of forest-dependent birds was higher in IOC farms than in shade coffee farms, and was comparable to secondary forest sites. There was no difference in species richness of Neotropical-Nearctic migrants between IOC and shade coffee farms. Overall similarity was higher between IOC farms and primary forest than between shade coffee farms and primary forest. he golden-winged warbler Vermivora chrysoptera is a declining Neotropical-Nearctic migrant bird, yet little is known about its non-breeding season ecology and demographics. I found that golden-winged warbler abundance was highest at intermediate precipitation levels found at middle elevations (1000-1200 m) of the Pacific slope, but they were absent from the dry forests at lower elevations on the Pacific slope. Abundance peaked in forests with canopy heights of 22 m, and was positively related to the quantity of hanging dead leaves. Radio-telemetry data indicated that golden-winged warblers used microhabitat features characteristic of disturbance more frequently than expected by chance. Selection of these microhabitat features was related to their highly specialized dead-leaf foraging behavior, which may also have contributed to their high degrees of site fidelity, mixed-species flock attendance, and territoriality. These behaviors have important conservation implications because they constrain density, and thus could affect carrying capacity. Population dynamics were characterized by estimating plot-level and individual-level apparent survival and recruitment rates within and among non-breeding seasons. Both levels of analysis suggested that recruitment was too low to offset mortalities within this study area. This study indicates that increasing forest cover in tropical agricultural landscapes may be the most effective way of providing habitat for bird species of high conservation concern, including the golden-winged warbler. Integrated open canopy coffee production is one option for achieving this goal because it provides a financial incentive to protect or restore forest.

Montane forests provide habitat for unique assemblages of flora and fauna that contribute significantly to a region’s biodiversity. Previous work indicates that montane forest ecosystems are exceedingly vulnerable to a host of anthropogenic stressors including climate change, atmospheric deposition, and recreation, to name a few. Montane forests and other high elevation ecosystems are considered to be among the first and most severely impacted by climate change. It is therefore, imperative to evaluate anthropogenic impacts on montane ecosystems and maintain reliable monitoring methods that are capable of tracking potential shifts in the distribution of species dependent on these systems. I surveyed birds at various distances from hiking trails in the White Mountain National Forest from 2006 - 2009 to determine whether existing monitoring programs, all of which are based on trail-centered surveys, are accurately reflecting bird abundance, abundance stability and recruitment. Contrary to previous studies, I found that recreational trails generally did not alter estimates of abundance, recruitment, abundance stability, and detection probability for five species of birds considered to be indicators of montane forest ecosystem integrity in northeastern North America. Therefore, trail-based monitoring programs for montane birds appear to accurately reflect dynamics of bird communities undisturbed by hiking trails. These conclusions were supported by my finding that the daily nest survival of a montane spruce-fir indicator species, blackpoll warbler (Steophaga striata), did not vary as a function of distance from trail. I then used data from the White Mountain National Forest’s montane bird monitoring program from 1994 through 2009 to assess potential shifts in the elevational distribution of montane birds in conjunction with documented habitat shifts in the region. My results provide evidence that low elevation forest birds have expanded their upper elevational boundary while high elevation birds have expanded their lower elevation boundary. These results highlight the complicated relationship between habitat, climate, and other anthropogenic stressors such as atmospheric deposition and that even in the face of climate change other stressors may be playing a significant role in shifts of species distributions. Understanding how climate affects the reproductive ecology of montane organisms is an important step toward unraveling the potential mechanisms by which climate change will alter the distribution of these species. I used blackpoll warbler breeding data from the Green Mountains, VT from 1994 to 2003 to determine if temporal variation in climate influenced blackpoll nesting initiation and found that years with warm Mays and typical precipitation lead to earlier nest initiation. I also examined the effect of spatial variation in climate on blackpoll reproductive ecology and demography. I found a gradient in habitat quality associated with the spatial variation in climate along an elevation gradient. Blackpolls were less abundant, younger, had lower pairing success, lower daily nest survival, higher nest predator occupancy, and lower fecundity at lower elevations. The climatic conditions at these lower elevations represent the climatic conditions predicted to encompass increasingly larger portions of montane areas. Collectively, these findings contribute to filling in a dearth of knowledge regarding management and an understanding of how species dependent on montane ecosystems are responding to climate change.

The effects of water and dietary influence, and time duration for discernment, of pectoral fin spine 87Sr/86Sr were evaluated in Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus. Fish were subjected to 87Sr-enriched water (0.1 mg/L) or diet (0.25 migrogram/g or 0.5 microgram/g) for 1, 2, 3, 6, or 12 weeks. Fish were also held at 15 or 25°C to determine if temperature influenced 87Sr/86Sr. Results found fin spine 87Sr/86Sr changed in water after 1 week and diet after 12 weeks suggesting water is the primary influence. In wild Gulf Sturgeon A. o. desotoi, spot ablations closest to the fin spine core separated fish into four 87Sr/86Sr groups (0.7110, 0.7105, 0.7100, and 0.7906) for both the Pascagoula and Pearl Rivers from 2016-2021. In the Pearl River system, 87.5% of fish (pre-first annuli) had stable 87Sr/86Sr indicating minimal movement, whereas decreasing 87Sr/86Sr in the second and third growth zones indicated downriver movement towards estuaries.

This thesis is concerned with the fisheries of Deer Creek Reservoir, Wasatch County, Utah, with special emphasis on the yellow perch. The study period was from May 13 to November 24, 1968. Objectives included the determination of size, age, and food habits of the yellow perch. Parasitic occurrences in the perch population by Ligula intestinalis were also recorded as well as the utilization of the perch by the fishermen. Observations on other species of fish including an analysis of rainbow trout stocking programs were also objectives of this thesis. Data was gathered by means of creel census and fish collection techniques. Collections were made by use of seine, hook and line, shocking and experimental gill nets.

Microplastics are widespread and abundant. Few studies have examined the diversity and abundance of microplastics in wild organisms. This study determined the microplastic quantity and types in the organic tissues of the eastern oyster Crassostrea virginica and Atlantic mud crab Panopeus herbstii from the Indian River Lagoon (IRL). This study also investigated whether location affected the microplastic abundance and variety. Organisms were collected from three sites across Mosquito Lagoon in the northern IRL. Oysters were frozen after collection. Crabs were placed in containers for 5 days before freezing. The soft organic tissue was chemically digested using hydrogen peroxide, filtered, and examined for microplastics. Water samples collected from each study site had an average of 23.1 microplastic pieces per liter and fibers were the most common type. There was a significant interaction for microplastic type and site for both oysters and crabs (p

The dwarf wedgemussel (Alasmidonta heterodon) is a federally endangered freshwater mussel that once ranged from New Brunswick to North Carolina, but now only exists in isolated populations throughout its diminished range. Laboratory propagation in conjunction with augmentation or reintroduction is considered a critical component of dwarf wedgemussel restoration. My thesis aimed to I) develop in-vitro propagation techniques including methods to minimize microbial contamination for two Alasmidonta species and II) compile and assess critical fish assemblage information at existing dwarf wedgemussel presence and absence locations to inform future restoration activities. For the first objective (Chapter 2) I assessed three methods of contamination mitigation (media change frequency, concentration of the antifungal Amphotericin B, and method of antifungal replenishment). Across all experiments, higher levels of contamination severity had a negative impact on transformation success. In my experiments, dishes that had media changes every other day (vs. those changed daily and every 3 days) had the highest contamination and the lowest glochidia transformation success. Treatments with the lowest (0 µg/mL) concentration of the antifungal, Amphotericin B, and got a low-dose replenishment of Amphotericin B (vs frequent media changes) had the highest transformation success. The fungus was identified as Candida parapsilosis, a common fungus found in aquatic and human environments; future propagation efforts should use mitigation methods that are specific to the fungal contaminant. In the assessment of host fish near dwarf wedgemussel locations (Chapter 3), two fish repeatedly emerged as indicators of dwarf wedgemussel occurrence and abundance: the tessellated darter (Etheostoma olmstedi) and brown trout (Salmo trutta). Tessellated darter was positively related to dwarf wedgemussel which supports the importance of tessellated darter as a host fish in the wild. The negative relationship between dwarf wedgemussel and brown trout may indicate a difference in habitat between the species or brown trout’s predation upon wild hosts. Results from this project will be used in conjunction with habitat and genetic information to inform future restoration plans in the northeast and add to the growing body of literature on in-vitro propagation of freshwater mussels.