I used incubation baskets containing viable eggs and spawning substrate to estimate the survival to emergence and time of emergence of kokanee salmon Oncorhynchus nerka at depths to 20 m in Flaming Gorge Reservoir, Utah-Wyoming. Traps on the incubation baskets captured fry emerging from a known quantity of eggs. Water drawn into a syringe from an intragravel pipe buried near each incubation basket was used to determine intragravel dissolved oxygen concentrations throughout the intragravel period. Water from control baskets without eggs did not have significantly greater dissolved oxygen concentrations than adjacent water. A jar associated with each incubation basket collected sediment to determine absolute and organic sedimentation during the study. Temperatures at the substrate water interface were used to describe degree-days accumulated before emergence. Survival to emergence ranged from zero to 66% and was most significantly related to mean intragravel dissolved oxygen concentrations. Survival to emergence, mean intragravel dissolved oxygen concentrations , and organic sedimentation decreased with depth.

Current solutions of coral restoration rely mainly on fragmentation. Though a reliable technique, this asexual form of reproduction does not benefit the genetic diversity of the coral reef. With many global and local stressors threatening corals’ existence, the resiliency of corals to future ocean conditions depends highly on sexual reproduction to produce new genotypes. New technology allows coral spawning/larval release, larval settlement and rearing to be carried out in an aquarium system. Many of the techniques necessary to maintain coral recruits are well-established, however the effects of light intensity remain to be studied for these early life stages. Newly settled corals have been found on vertical surfaces and the undersides of ledges and crevices, suggesting full solar irradiance is detrimental to their health. Newly settled Porites astreoides and Agaricia agaricites recruits were placed under varying irradiance levels to test their survivorship, growth and pigmentation. In the first four weeks post-settlement, growth was significantly different between recruits under a PAR of 10 µmol quanta m-2 s-1 and 240 µmol quanta m-2 s-1. In a separate experiment, growth curves were significantly different between six different irradiance increase regimens in the first 14 weeks post-settlement. This study shows, for the first time, a definitive preference by newly settled coral recruits to lower intensity irradiance, devoid of ultraviolet radiation, in the first four weeks post-settlement, and that Porites astreoides recruits can acclimatize to higher intensities at a rate of ~ 11 µmol quanta m-2 s-1 per week for up to 15 weeks.

The study of fish diets or feeding behavior is an important aspect in ecology. Analysis of fish stomach contents often provides data for determining resource utilization, feeding strategies, and overlaps in food items among and between species. Studies of fish diets could also be used for testing ecological theory or provide management procedures for fisheries if methods could be developed for minimizing competitive food utilizations by other fish and enhancing growth of exloited fish populations (Obrebski and Sibert 1977). In order to understand more about ecological communities and competitive predatory relationships of fish, more data are required on their diets and feeding habits (Pearcy and Hancock; 1973). Detailed accounts of prey items consumed by some flatfish in the northwest Pacific are by Hagerman (1952), Kravitz et al. (1977), and Pearcy and Hancock (1978). This study examines the diet and growth of two juvenile flatfish, the English sole, Parophrys vetulus (Girard 1854) , and the Speckled sanddab, Citharichthys stiamaeus (Jordan and Gilbert 1832). In the present study the English sole and Speckled sanddab are investigated in order to determine their growth and seasonal changes in their diets, switching of food items, and overlaps of diet items between species and among size groups within species.

The study of insects has been a hobby for me for more than twenty years. Their diversity and adaptation to many habitats has been of particular interest. Ever since the removal of my first aquatic nymph from the crashing waters of the American River, I have been especially fascinated, with these insects. Since I had access to a relatively undisturbed year round stream, I chose to study the aquatic insects of this stream. The purpose of this study was to survey the aquatic insect fauna of Mill Creek during the course of a year and relate these findings to the River Continuum Concept.

Studies on trematodes of marine organisms of the Pacific Coast have been of a scattered and fragmentary nature. J. Stafford (1904) collected and described a number of trematodes from fishes of the north Pacific, but, in his historical survey, Manter (1926) fails to mention specifically any studies covering the waters south of Canada. More recently, in the United States, several contributions to the field have been made by Dr. John E. Guberlet at the University of Washington and at the College of the Pacific by Dr. Alden Noble, under whose guidance this study was made. James Park (1937) revised the genus Podocotyle and added eight new species .from Dillon Beach, California. Descriptions of individual trematodes have been made by various other investigators. The investigation covered by this paper was begun during the summer or 1946 at the Pacific Marine Station.

Jaguar Guapote (Parachromis managuensis) and Amphilophus spp. were assessed for effects of temperature on standard metabolic rate (SMR) and lower dissolved oxygen tolerance (LDOT), efficacy of gastric lavage for diet analysis, and diet in Puerto Rico reservoirs. Fish were acclimated to 22°C, 28°C, and 34°C and SMR and LDOT were measured using intermittent respirometers. Jaguar Guapote acclimated to 34°C had the greatest SMR, with 22°C and 28°C having similar SMR values. Amphilophus spp. acclimated to 28°C were similar to fish acclimated at 22°C and 34°C. Fish were resilient to high temperatures, losing equilibrium more rapidly at the coldest temperature, 22°C. Gastric lavage had low to moderate efficacy in extracting diet from cichlids. Diet in reservoirs differed among all species but overlap was present, suggesting cichlids in Puerto Rico may impact sportfish populations. These findings are important for making informed management decisions.

A new macroscopic ovarian reproductive maturity index for haddock, Melanogrammus aeglefinus L, was developed to improve field collection of reproductive stage data. The index was tested, validated and revised based on a comparison with a laboratory histological staging method. The comparison of field and histological observations helped to improve the field index and methodologies and provided useful insight into the reproductive biology of Haddock. Although laboratory staging based on histology is inherently more accurate than any macroscopic field staging method, field observations can reveal weaknesses in the laboratory approach due to sampling bias. The revised field index includes three new macroscopic stages that represent a progression in final oocyte maturation from early to late, which were found to be reliable for staging spawning readiness in the field. This index was then used to study a population of Haddock in the Gulf of Maine to determine if it exhibits diel spawning periodicity. Commercial fishing vessels were chartered for 25 dedicated longlining trips to collect sexually mature haddock in the Southwestern Gulf of Maine at locations identified by commercial fishers as having spawning aggregations. In order to examine diel effects on haddock reproduction, the change in catch per unit effort and percentage of male and female haddock of all reproductive maturity stages together with the gonadosomatic index were observed across a 24 hour diel cycle. Only females in hydration stage 3 (defined as late final oocyte maturation stage ovaries with 50-75% of oocytes hydrated) were significantly affected by time of day with significant increases in both catch per unit effort and percentage of hydration stage 3 haddock during the night. Because H3 is the most advanced reproductive stage observed prior to a spawning event and therefore the best indicator of imminent spawning these results demonstrate that female haddock in Southwestern Gulf of Maine primarily spawn during night hours with a peak between 2100 and 0100 hours. No diel trend was observed for any male reproductive stages. Additionally, no diel trend was observed in male or female reproductive stages unrelated to spawning including immature, spent and resting.

An investigation into the spatial ecology and effects of catch-and-release angling on the physiology and behavior of striped bass was conducted. Fine-scale behavior was assessed by tagging fish with acoustic transmitters equipped with pressure and tri-axial accelerometer sensors and tracking them within a fixed array (n=34 receivers) in a Massachusetts estuary. Activity space changed significantly over the course of the season and increased with water temperature. Striped bass most frequently exhibited low levels of locomotory activity representing 67% of total activity measurements, with occasional high activity and burst swimming, often within the upper 3 m of the water column. Depth distribution of striped bass remained shallower when temperatures peaked at over 21 oC. Diel vertical migration was present with shallowest depths observed during the day and greatest depths during high tide. To investigate catch-and-release consequences, 102 striped bass were angled and blood sampled between July and November 2011. A subsample of 35 striped bass (July n=11, August n=11, September n=13) were implanted with tri-axial acoustic accelerometers to assess relative behavior and survival post-release. Results from principle component analyses produced five factors describing 72.7% of the variance for blood physiology parameters, total length, and water temperature. Subsequently, only eigenvalues from PC1, with high loading for blood lactate, plasma sodium and chloride, and total length, were significantly correlated with fight time. Eight individual fish were detected within 12 hours of release and exhibited their greatest mean daily activity space estimate within that time (1.5 km2 ± 0.6, 50%; 5.6 km2 ± 2.2, 95%). Depth ranged from 0-6.15 m (1.89±1.3 m) and acceleration ranged from 0.095-3.51 ms-2 (0.95±0.33). In summary, no observed mortality suggests that fish were able to recover from the physical and physiological impacts of angling. This thesis has increased the understanding of striped bass ecology and will help promote future conservation and management initiatives for striped bass and facilitate additional research.

Recent years have seen an explosion of interest in the use of freely available DNA present in aquatic systems, otherwise known as environmental DNA (eDNA), as a tool for monitoring aquatic organisms. However, much remains unknown about the behavior of eDNA over a range of environmental conditions. This is particularly true in high gradient headwater streams, which have received less attention than other types of water bodies. In the summer of 2011, a headwater stream system with well established species distributions was sampled using eDNA techniques. Though species were detected where known to be present, detections also occurred where traditional techniques failed to detect species. This suggests that a cautious approach to positive eDNA detections is advisable. In 2012 a second study was conducted to better understand the dynamics of eDNA concentration in lotic systems. Caged brook trout (Salvelinus fontinalis) were introduced into two otherwise fishless headwater streams, and eDNA samples were collected at evenly spaced intervals downstream of the cage. This was repeated 19 times from mid-summer through autumn, over flows ranging from approximately 1 to 96 l/sec. Quantitative PCR was used to relate DNA copy number to distance from source for each of these 19 sampling events. In all cases, DNA was detectable at 239.5 m from the cage. Increasing flows generally decreased eDNA copy number near the cage but had relatively little effect at downstream sites. Additionally, the presence of leaf biomass during the fall period had the potential to completely erase otherwise high DNA levels.

Aquaponics is the combination of aquaculture and hydroponic technology to grow both fish and plants together in a closed-loop system. While aquaponics can play a role in increasing food security, it may also be a potential educational tool because of its interdisciplinary nature and required technological skill set. With aquaponics, students could conduct hands-on activities involving chemistry, physics and biology to solidify their understanding of a range of theories. Beyond standard science, technology, engineering and mathematics (STEM) principles, aquaponics may be related to projects on sustainability, environmental science, agriculture, the food system, health, economics, business and marketing. The interdisciplinary nature of aquaponics may make it an appealing tool for education, yet that same aspect may also make an aquaponics system challenging to implement and manage. Given this paradox, this exploratory research assesses challenges, solutions and success of aquaponics in education with a specific focus on implementation. Qualitative data were collected through phone interviews with educators (n=10) who currently, or had in the past, used an aquaponics system in an educational setting in North America. The most frequently described uses for aquaponics were flexible, hands-on teaching and learning of STEM and food-related concepts. Participants reported two broad challenges to implementing aquaponics: technical difficulties as a result of the nature of aquaponics and restrictions as a result of their school settings. Solutions given by participants were physical aquaponics system modifications and the development of intangible characteristics, especially community connections and support, passion for aquaponics and expertise. In this study, success in aquaponics in education emerged as a cyclical pattern: participants valued the overall learning experiences of aquaponics and the continued application of these learning experiences. Ultimately, these exploratory findings will help educators manage their expectations for aquaponics while establishing objectives for their particular educational settings.