The behaviour of Atlantic salmon (Salmo salar) on first migration to sea

The Atlantic salmon, Salmo salar Linnaeus 1758, is a charismatic species due to its cultural and economic importance across the North Atlantic. In addition, Atlantic salmon is one of the most well researched finfish species. However, there are still considerable knowledge gaps concerning their life history, particularly for salmon smolts migrating from rivers in the British Isles. To date management and research efforts have been largely focussed on improving and understanding salmonid migration through fresh water habitats. Despite these management efforts, Atlantic salmon populations continue to decline. This has led researchers to speculate that the decline may be related to factors encountered at sea, particularly within the early marine environment. This thesis has filled in knowledge gaps concerning the migratory behaviour of Atlantic salmon smolts migrating from rivers draining into the West Coast of Scotland and Ireland using acoustic telemetry. Despite the fresh water environment being the main focus of Atlantic salmon research, very little is known about how Atlantic salmon navigate through fresh water standing bodies of water. This is concerning, as previous studies have suggested that smolts experience high rates of mortality in these regions and display non-directional movements. Through combining acoustic telemetry data with a correlated random walk model, I sought to determine what factors may increase the likelihood of smolts completing a successful migration through Scotland's largest lake. This study demonstrated that consistent with previous literature smolts experienced high overall loss (43%), slow migrations, and non-directional movements. Furthermore, there were no behavioural or morphological factors that differentiated a successful versus unsuccessful migrant, with most individuals travelling upwards of 50 km within the lake. In addition, migratory pathways of smolts closely resembled random walk models, suggesting that successful migration of smolts through lakes is due to chance. However, once smolts came near the lake outlet they tended to make a direct exit. Within the main body of most lakes, surface currents are largely driven by the wind. However, near the lake outlet currents are often directed towards the lake outflow. Future studies are required to determine whether currents are the main environmental cue used by smolts to navigate through fresh water standing bodies of water. Once Atlantic salmon smolts transit through their fresh water environment, many populations must first navigate through estuaries prior to reaching the early marine environment. Estuaries are thought to be a region of high mortality for Atlantic salmon post-smolts as they are exposed to a variety of novel natural and anthropogenic stressors such as predators and aquaculture sites. Scotland is one of the worlds largest producers of farmed salmon, with most aquaculture sites being present along the north-western coast within sea lochs and estuaries. However, despite the rapid expansion of aquaculture sites in the UK, there is limited knowledge concerning the behaviour of wild Atlantic salmon in estuaries and whether they could experience spatial overlap with these sites. The Clyde estuary located in west central Scotland is a region that currently contains 16 operational aquaculture sites with plans to develop more in the future. Using acoustic telemetry coupled with a mark-recapture model, this study predicted the migratory pathways and estimated loss rates of Atlantic salmon post­smolts from two distinctly different river systems (Endrick Water & River Gryffe). In comparison to most literature assessing smolt post-survival through estuaries, loss rates were low <1 %km -1. This is despite 37% of post-smolts making~ 2 reversal movements near the riverine outlet upon entering the estuary, which is thought to be related to a need to adapt to the increase in salinity. In addition, post-smolts were found to make rapid migrations through this region and appeared to exit the estuary with the outgoing tide. Due to their rapid migrations through this region, and high rates of survival, it does not appear that aquaculture sites in the main body of the Clyde estuary have a significant effect on Atlantic salmon post­smolts from the Endrick Water and River Gryffe. This information is currently being used by the Scottish Environment Protection Agency (SEPA) to develop models assessing the impact of sea lice on wild Atlantic salmon. Research directed surface trawls conducted along the continental shelf of Scotland have indicated that once post-smolts leave rivers located along the western coast of UK and Ireland they migrate north towards the slope current, using this current to reach their feeding grounds in the Norwegian Sea. However, to date very little is known about the migratory pathways taken and environmental cues used by post-smolts to reach the slope current. Particle tracking studies conducted along the western coast of Scotland have indicated that for post-smolts to reach the slope current during the period when they are captured by trawling studies, they would have to deviate from local current patterns early on in their migration. This thesis was the first to ground truth particle tracking studies in the Irish Sea region through collecting acoustic telemetry data from 582 Atlantic salmon post-smolts from 13 rivers in England (n = 1) and Scotland (n = 12) detected on a large acoustic telemetry array deployed at the Irish Sea exit (n = 108 receivers). Furthermore, using circular statistics detection data was combined with two hydrodynamic models (current/temperature data) to determine potential drivers of early marine migration. Post-smolts from all river systems were found to undergo relatively rapid migrations through the Irish Sea(> 10 km.day-1) and loss rates were low. However, when loss rates were multiplied by the total distance travelled there was still substantial overall loss for post-smolts migrating from English and Scottish rivers. Post-smolts exit from the Irish Sea appeared to be initiated by water temperature with most post-smolts exiting when temperatures ranged from 9 - 11 °C. These temperatures are similar to those reported when post-smolts are captured in the slope current. In addition, most post-smolts exited this region when currents were directed westwards towards the slope current located off the continental shelf. Thus, results from this study suggest that temperature and current direction may serve as environmental cues used by post-smolts during their early marine migration to determine when and where to migrate. Similar to their migration through the Irish Sea, prior to this thesis there was limited information concerning the migratory pathways post-smolts may use to migrate along the west coast of Scotland towards the Norwegian Sea. Further research was needed, as the highest density of anthropogenic stressors ( e.g. aquaculture sites, renewable energy developments) in Scotland are located to the east of the Outer Hebrides. Through collaborating with a colleague at the Atlantic Salmon Trust and combining data from seven acoustic telemetry projects taking place in England, Scotland, and Ireland during 2021, we were able to document the migration pathways of post-smolts through this region. This study incorporated data from 23 rivers (n = 1806 post-smolts), 398 acoustic receivers and one submersible glider. In total 34.7% of tagged post-smolts (n = 416) that left their natal river (n = 1200) were detected in the coastal marine environment. Furthermore, consistent with the results from my previous chapter, most post-smolts travelling from rivers south of the Outer Hebrides were found migrate in a north­westerly direction towards the slope current located off the continental shelf of Scotland. However, post-smolts migrating from rivers to the east of the Outer Hebrides travelled directly through the Minch. The four chapters presented in this thesis have utilized acoustic telemetry data to model the behaviour and survival of Atlantic salmon smolts from multiple populations in lakes, estuaries, and the early marine environment. The results obtained from this thesis will be used by researchers and managers to help develop future studies aimed at identifying and mitigating the effects of potential stressors unique to each Atlantic salmon population mentioned in this project

Lower Extremity Strength and Mobility in Division I Male Basketball Players Across Vertical Jump Performance

Vertical jump (VJ) performance is a commonly used assessment to measure explosive muscular power in collegiate strength and power athletes such as basketball players. However, research on the relationship between VJ performance and measures of lower extremity (LE) strength and mobility is inconsistent. PURPOSE: The purpose of this study was to analyze hip and ankle strength and mobility measures among collegiate male basketball players by comparing those with higher and lower VJ performance. METHODS: During pre-season screening, ten Division I male basketball players were assessed to determine VJ height by completing a countermovement VJ test. Players were divided into two groups based on VJ performance which were comprised of the top 5 performers (T; 20.8 ± 2.0 years, 186.4 ± 7.4 cm, 79.6 ± 8.6 kg; VJ: 70.4 ± 6.9 cm) and the bottom 5 performers (B; 20.0 ± 1.6 years, 197.4 ± 9.9 cm, 94.2.6 ± 19.7 kg; VJ: 56.9 ± 2.5 cm). Hip range of motion (ROM) was measured with a goniometer, and total hip ROM was calculated as the sum of internal and external rotation for each limb. Ankle dorsiflexion was assessed using a clinometer instrument. Hip abduction (ABD) and adduction (ADD) strength was measured using a dynamometer, and calculated relative to body weight. Players also self-reported LE injuries in the prior 12 months. Descriptive statistics were calculated as mean ± standard deviation. RESULTS: Compared to B, T had lower left leg hip ROM (69.4 ± 6.6° vs 72.6 ± 7.5°). T had higher right leg hip ROM (73.4 ± 5.0° vs 70.0 ± 11.9°) and left/right ankle ROM (36.8 ± 4.1° vs 33.2 ± 3.0° and 35.4 ± 2.4° vs 32.8 ± 4.0°, respectively). T had higher relative right/left leg ABD strength (43.5 ± 6.3 vs 37.5 ± 10.9 % and 37.8 ± 7.1 vs 36.8 ± 11.8 %, respectively), and right/left leg ADD strength (44.0 ± 21.4 vs 40.9 ± 6.1 % and 41.2 ± 10.5 vs 39.5 ± 12.3 %, respectively). However, only 20% of the T group compared to 60% of the B group reported experiencing a recent LE injury. CONCLUSION: Although the T group had higher right leg hip ROM, ankle ROM, and greater hip strength these were just trends, making it difficult to draw any inferences about the association between hip and ankle strength and mobility measures on VJ performance. It is also possible that the greater presence of recent LE injury in the B group may have impacted the findings of this study

Assessing the potential of acoustic telemetry to underpin the regional management of basking sharks (Cetorhinus maximus)

Acoustic telemetry can provide valuable space-use data for a range of marine species. Yet the deployment of species-specific arrays over vast areas to gather data on highly migratory vertebrates poses formidable challenges, often rendering it impractical. To address this issue, we pioneered the use of acoustic telemetry on basking sharks (Cetorhinus maximus) to test the feasibility of using broadscale, multi-project acoustic receiver arrays to track the movements of this species of high conservation concern through the coastal waters of Ireland, Northern Ireland, and Scotland. Throughout 2021 and 2022, we tagged 35 basking sharks with acoustic transmitters off the west coast of Ireland; 27 of these were detected by 96 receiver stations throughout the study area (n = 9 arrays) with up to 216 detections of an individual shark (mean = 84, s.d. 65). On average, sharks spent ~ 1 day at each acoustic array, with discrete residency periods of up to nine days. Twenty-one sharks were detected at multiple arrays with evidence of inter-annual site fidelity, with the same individuals returning to the same locations in Ireland and Scotland over 2 years. Eight pairs of sharks were detected within 24 h of each other at consecutive arrays, suggesting some level of social coordination and synchronised movement. These findings demonstrate how multi-project acoustic telemetry can support international, cost-effective monitoring of basking sharks and other highly mobile species. Decision support tools such as these can consolidate cross-border management strategies, but to achieve this goal, collaborative efforts across jurisdictions are necessary to establish the required infrastructure and secure ongoing support

Intravesical Treatments of Bladder Cancer: Review

For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy

In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

Inshore and offshore marine migration pathways of Atlantic salmon post-smolts from multiple rivers in Scotland, England, Northern Ireland and Ireland

The migratory behavior of Atlantic salmon (Salmo salar) post-smolts in coastal waters is poorly understood. In this collaborative study, 1914 smolts, from 25 rivers, in four countries were tagged with acoustic transmitters during a single seasonal migration. In total, 1105 post-smolts entered the marine study areas and 438 (39.6%) were detected on a network of 414 marine acoustic receivers and an autonomous underwater vehicle. Migration pathways (defined as the shortest distance between two detections) of up to 575 km and over 100 days at sea were described for all 25 populations. Post-smolts from different rivers, as well as individuals from the same river, used different pathways in coastal waters. Although difficult to generalize to all rivers, at least during the year of this study, no tagged post-smolts from rivers draining into the Irish Sea were detected entering the areas of sea between the Hebrides and mainland Scotland, which is associated with a high density of finfish aquaculture. An important outcome of this study is that a high proportion of post-smolts crossed through multiple legislative jurisdictions and boundaries during their migration. This study provides the basis for spatially explicit assessment of the impact risk of coastal pressures on salmon during their first migration to sea

Mechanical design of the optical modules intended for IceCube-Gen2

IceCube-Gen2 is an expansion of the IceCube neutrino observatory at the South Pole that aims to increase the sensitivity to high-energy neutrinos by an order of magnitude. To this end, about 10,000 new optical modules will be installed, instrumenting a fiducial volume of about 8 km3. Two newly developed optical module types increase IceCube’s current sensitivity per module by a factor of three by integrating 16 and 18 newly developed four-inch PMTs in specially designed 12.5-inch diameter pressure vessels. Both designs use conical silicone gel pads to optically couple the PMTs to the pressure vessel to increase photon collection efficiency. The outside portion of gel pads are pre-cast onto each PMT prior to integration, while the interiors are filled and cast after the PMT assemblies are installed in the pressure vessel via a pushing mechanism. This paper presents both the mechanical design, as well as the performance of prototype modules at high pressure (70 MPa) and low temperature (−40∘C), characteristic of the environment inside the South Pole ice

The next generation neutrino telescope: IceCube-Gen2

The IceCube Neutrino Observatory, a cubic-kilometer-scale neutrino detector at the geographic South Pole, has reached a number of milestones in the field of neutrino astrophysics: the discovery of a high-energy astrophysical neutrino flux, the temporal and directional correlation of neutrinos with a flaring blazar, and a steady emission of neutrinos from the direction of an active galaxy of a Seyfert II type and the Milky Way. The next generation neutrino telescope, IceCube-Gen2, currently under development, will consist of three essential components: an array of about 10,000 optical sensors, embedded within approximately 8 cubic kilometers of ice, for detecting neutrinos with energies of TeV and above, with a sensitivity five times greater than that of IceCube; a surface array with scintillation panels and radio antennas targeting air showers; and buried radio antennas distributed over an area of more than 400 square kilometers to significantly enhance the sensitivity of detecting neutrino sources beyond EeV. This contribution describes the design and status of IceCube-Gen2 and discusses the expected sensitivity from the simulations of the optical, surface, and radio components

Sensitivity of IceCube-Gen2 to measure flavor composition of Astrophysical neutrinos

The observation of an astrophysical neutrino flux in IceCube and its detection capability to separate between the different neutrino flavors has led IceCube to constraint the flavor content of this flux. IceCube-Gen2 is the planned extension of the current IceCube detector, which will be about 8 times larger than the current instrumented volume. In this work, we study the sensitivity of IceCube-Gen2 to the astrophysical neutrino flavor composition and investigate its tau neutrino identification capabilities. We apply the IceCube analysis on a simulated IceCube-Gen2 dataset that mimics the High Energy Starting Event (HESE) classification. Reconstructions are performed using sensors that have 3 times higher quantum efficiency and isotropic angular acceptance compared to the current IceCube optical modules. We present the projected sensitivity for 10 years of data on constraining the flavor ratio of the astrophysical neutrino flux at Earth by IceCube-Gen2