Modifications to Brandon Road Lock and Dam (BRLD), located on the Des Plaines River in northeastern Illinois, have been proposed to prevent the upstream transfer of aquatic invasive species, particularly Asian carps, into the Great Lakes Basin. These modifications, including the installation of an electric barrier, acoustic fish deterrent, and air bubble curtain, are designed to completely eliminate all upstream fish passage and may negatively impact native fish populations in the Des Plaines River by reducing upstream movement and potentially fragmenting populations. BRLD is situated just 21 km upstream of the Des Plaines River mouth, and fish are only able to pass upstream via the lock chamber. Fish species richness within the Des Plaines River watershed has increased over the last 35 years. It has been suggested that the majority of new species to the upper Des Plaines River have migrated upstream past Brandon Road Lock and Dam (BRLD), from the Illinois, Kankakee, and lower Des Plaines rivers. However, documentation of emigration needed to support that contention is lacking and there is limited knowledge of the current rate of BRLD passage by native species. To assess native fish passage through the lock, a microchemical study was conducted using fin rays from fish collected from the Des Plaines, Illinois, and Kankakee Rivers. The edge of each fin ray, which contained the most recently deposited material, was assumed to contain a microchemical signature reflective of residency in the river where the fish was sampled. Fin ray edge strontium:calcium ratio (Sr:Ca) was used to define taxonomic and river-specific signature ranges for four taxonomic groups: centrarchids, catostomids, ictalurids, and lepisosteids. Fin ray edge Sr:Ca data were input into a random forest classification model, and the classification accuracy of fish to their river of capture based on their fin ray edge Sr:Ca was > 97% in each taxonomic group. The classification model was then applied to the entire fin ray of each fish sampled upstream of Brandon Road to infer retrospective environmental history. Upstream BRLD lock passage was suggested by the presence of Sr:Ca signatures indicative of prior downstream residency in the Illinois or Kankakee rivers in a fish sampled upstream of BRLD. Results indicated some evidence of downstream residency that suggested upstream BRLD lock passage for centrarchids, catostomids, ictalurids, and lepisosteids, ranging from 15 – 37% of individuals sampled depending on taxa. An additional 19 – 80% of individuals within each taxonomic group were classified as fish with uncertain downstream residency, whereby the possibility of BLRD lock passage could not be rejected, but there was higher uncertainty in establishing downstream residency in the Illinois or Kankakee rivers. The impact of BRLD modifications and passage restriction on Des Plaines River fish populations is unknown and merits further investigation.

Master of Science / Biology / Keith B. Gido / Negative interactions with nonnative fish are often cited as a leading cause of declining native fish populations, but quantifying these interactions is difficult. Movement ecology and consumptive demand estimates of nonnative fish predators is needed to better understand potential impacts these organisms are having on native species. The objective of this thesis were to estimate the consumptive demand of Flathead Catfish Pylodictis olivaris on native fishes across an elevational gradient, and characterize the movement at hourly, daily, and seasonal scales of this introduced predator. This research was conducted in the upper Gila River basin of southwestern New Mexico. Bioenergetics modeling was used to estimate consumptive demand; model results were coupled with measured densities and size structure of Flathead Catfish populations, and water temperatures, to predict its predatory threat. Potential consumption was highest at lower elevation sites because of higher water temperatures, but actual consumption was highest at mid-elevation sites because of the prevalence of large-bodied individuals. Potential annual consumptive demand of Flathead Catfish on native fish across our nine sampling sites ranged from 0.0 to 3.1 g/m²/yr, which exceeded native fish productivity at one site. To characterize the movement of Flathead Catfish, we used radio telemetry and tracked individuals from May 2014 to June 2015. Movement behaviors varied among individuals with a majority moving <150 m from capture location and some more mobile, moving substantial distances (692-42,840 m). During the course of the study, activity was greatest in summer and fall, and individuals moving substantial distances moved downstream to warmer river reaches before the winter. Nightly movements only involved short distances (5 m) and no fish exceeded a single movement >80 m. Daily activity was greatest during evening but late afternoon activity was observed in summer and fall. Results from this study identify areas within the upper Gila River where introduced Flathead Catfish consumption is likely to negatively impact native fish populations and managers can use this information to understand potential overlap with native species, target future removal efforts in areas where these fish are concentrated, and avoid stocking native fishes in reaches where Flathead Catfish tend to aggregate.

Area closures have been widely used in the management of migratory fish and conservation of endangered marine species, but very few economic models are available to assess the impacts of a closure because economists have paid little attention to complexities in fishery management, such as spatial heterogeneity in fish stocks and fleet dynamics. This study presents a spatial economic model that features (i) heterogeneously distributed stocks of multiple species, (ii) their movement across areas, (iii) travel costs depending on fishing location, and (iv) optimal allocation of fishing trips to areas and of the primary target in each fishing set. Because catch-per-unit-effort (CPUE) diminishes with effort, trips are alternately allocated to several areas, where the expected crew's wages are equalized. While this optimal allocation of trips derives a demand for labor (DDL), fishermen's tradeoff between offshore days (labor) and onshore days (leisure) yields an upward-sloping labor supply curve, which determines, together with the DDL, the equilibrium level of wage and labor. Using catch and effort data summarized from the federally mandated commercial logbooks into 5° square monthly strata, auction price data, and survey data for longliner's cost structure, this model is applied to the Hawaii longline fishery to conduct policy simulations. While a near-shore area closure leads to fewer trips of longer duration, a closure of the North Pacific to protect sea turtles significantly reduces swordfish catch and significantly increases the catch of near-shore species, which may endanger the stocks of near-shore species or affect the harvests by other boats. The impacts of prohibiting swordfish sets on the industry could be more severe than the above closure for turtle conservation. A revenue tax is not effective in reducing fishing effort. A closure increases fish movement (FM) from the closed area to open, neighboring areas, resulting in higher levels of the stocks in those open areas. This FM effect benefits the fishery industry, and could reduce the fishermen's income loss from a closure--estimated by the model without FM--by half, if fish are mobile and the closed area(s) is a "source" in terms of the direction of movement.

The Red Sea is valued for its biodiversity and the livelihoods it provides for many. It now faces overfishing, habitat degradation, and anthropogenic induced climate-change. Marine Protected Areas (MPAs) became a powerful management tool to protect vulnerable species and ecosystems, re-establish their balance, and enhance marine populations. For this, they need to be well designed and managed. There are 15 designated MPAs in the Red Sea but their level of enforcement is unclear. To design an MPA it is necessary to know if it will protect species of interest by considering their movement needs. In this thesis I aim at understanding fish movement in the Red Sea, specifically home range (HR) to inform MPA size designation. With not much empirical data available on HR for Red Sea fish, I used a Machine Learning (ML) classification model, trained with empirical literature HR measurements with Maximum Total Length (L Max), Aspect Ratio (AR) of the caudal fin, and Trophic Level as predictor variables. HR was classified into 5 categories: <.1 km, 0.1- 1.0 km, 2.0- 5.0 km, 5.0- 20 km, and >20 km. The model presents a 74.5% degree of accuracy. With it, I obtained the HR category for 337 Red Sea fish species. Having MPAs with a maximum linear dimension of at least 10km will meet the requirements of 90% of fish species evaluated in the model, which were small to medium size families (damselfishes, butterflyfishes, small wrasses, cardinalfishes, gobies and blennies). This percentage does not include larger species likely to move over much greater distances (10s, 100s or 1000s of km) (e.g., medium to large jacks, snappers,, groupers, sharks and rays). 60% of the Red Seas designated MPAs have the potential, if enforced as a No Take Area (NTA), to benefit more than 95% of reef fishes. However, larger MPAs will be required to protect more wide-ranging species. TRSP project in Al Wadj is proposing to close the entire SEZ to fishing. If they are successful in implementing and enforcing this fishing ban, TRSP will be the largest no take area in the Red Sea (~160 km long) that is likely to not only protect all of the species evaluated in the model, but also most wide-ranging species. Therefore, TRSP is not only likely to achieve and surpass its stated goal of increasing current fish biomass by 30%, but also to provide benefits to surrounding areas through the spillover of adults, juvenile and larvae to fished areas.

An abundant Paddlefish Polyodon spathula population exists in a 0.8 ha pool below a water control structure at Sam D. Hamilton Noxubee National Wildlife Refuge, Mississippi. Managers were concerned that regulated flows from the structure were causing an ecological trap if Paddlefish were being attracted from the larger river downstream during the spawning period, but conditions were not suitable to facilitate reproduction. Between February 2016 to April 2018, 117 Paddlefish were identified and daily abundance was estimated between 18 and 75 fish. Telemetry study of 59 fish suggests a mixed population structure where some remain in the pool year-round and other emigrate seasonally, cued by rising spring discharge and water temperature. Reproduction was not documented which suggests a critical component needed for spawning may be missing, at least during this study. Therefore, given the need to remove Paddlefish from the pool, translocation and flow releases may be effective management strategies.

No description available.

The Staunton River is a high gradient, second order stream approximately 6 km in length located on the eastern slope of the Blue Ridge Mountains in Shenandoah National Park, VA. In June 1995, a catastrophic flood and debris flow altered the instream habitat and <i>Salvelinus fontinalis</i> population of the Staunton River. The debris flow scoured the streambed, deposited new substrate materials, removed trees from the riparian zone, and eliminated fish from a 1.9km section of the stream. By June 1998, both young-of-year (YOY) and age 1+ <i>S. fontinalis</i> had recolonized the debris flow affected area. The event provided a rare opportunity to examine recovery of the <i>S. fontinalis</i> population and instream habitat in addition to addressing potential effects of the debris flow on movement, activity, and growth of fish in the debris flow affected and unaffected areas of the stream. Post-recolonization movement and activity were monitored using two-way fish traps (weirs), mark-recapture techniques, and radio telemetry. The weirs failed to produce any movement data. Most fish (91%) in the mark-recapture study had range sizes less than 100m, however biases common to mark-recapture study designs (low recapture rate, flawed logic, etc.) hampered interpretation of results. For example, subsequent recapture of individually marked fish indicated that as many as 54% of marked fish confirmed to have been alive at the time of a recapture session were not recaptured. Radio telemetry provided information on <i>S. fontinalis</i> movement and activity at seasonal and diel scales during summer and fall. Differences in movement and activity between the debris flow affected and unaffected areas were minimal when compared to seasonal variations. During summer, range sizes were near 0m and crepuscular activity patterns were observed. During the fall range size increased and diel activity was concentrated in the mid-afternoon with a much higher peak than during summer. Basin-wide visual estimation technique (BVET) fish population surveys performed each spring and fall from 1993 = 1999 provided pre- and post-event fish population abundance and density estimates. Post-event fish growth in the debris flow affected and unaffected areas was monitored using mark-recapture techniques. Abundance and density of both YOY and age 1+ <i>S. fontinalis</i> exceeded pre-event levels within 2-3 years. Growth of YOY and age 1+ fish was significantly greater in the debris flow affected area until spring 1999. Population density appeared to have a strong negative influence on growth. The observed changes in fish growth and differences in fish size associated with population density would be of minimal importance to the typical angler but may suggest a mechanism by which <i>S. fontinalis</i> populations can quickly recover from catastrophic events. BVET habitat surveys provided information on total stream area, number of pools and riffles, pool and riffle surface area and depth, substrate composition, and large woody debris (LWD) before (1993), immediately following (1995), and four years post-event (1999). Immediately following the debris flow, the stream channel was highly disordered which resulted in an increase in the total number of habitat units and a decrease in average habitat unit surface area, total stream area, and average depth when compared with pre-event conditions. In addition, substrate composition had shifted from small to large diameter particles and LWD loading had increased in both debris flow affected and unaffected areas. Four years after the event, the total number of habitat units, average habitat unit surface area, total stream area, and average depth had all returned to near pre-debris flow levels and substrate composition had begun to shift towards smaller particle sizes. Changes in LWD loading from 1995-1999 reflected changes in the riparian zone following the debris flow. In the unaffected area, where riparian trees remained intact, LWD loading increased, whereas in the debris flow affected area, where riparian trees were eliminated, LWD loading decreased. For the most part the effects of the debris flow, although immediately dramatic, were in the long term minimal. The debris flow affected area was recolonized rapidly and abundance and density quickly rebounded past pre-event levels. Differences in fish growth between the affected and unaffected area were short lived. Any effect the debris flow affected area may have had on movement or activity was minimal when compared with seasonal variations. Most habitat characteristics reverted to near pre-event levels just four years after the flood and debris flow. Although a number of factors will influence recovery time from such events, these results indicate that immediate management action, such as stocking or habitat modifications, are not necessary in all cases. / Master of Science