White Bass Morone chrysops is a native, migratory sportfish that is found throughout the central United States in large rivers and riverine impoundments. White Bass migrate into tributaries and riverine portions of reservoirs to spawn during spring. These spawning migrations concentrate fish and may make them more susceptible to angling pressure. White Bass have been well studied in reservoirs throughout the central United States since the early 2000’s when fisheries management practices shifted from population management to fish assemblage management. However, despite the increase in White Bass research in reservoirs, large river populations remain understudied. My thesis research used otolith microchemistry to assess the role of tributaries in supporting White Bass populations in the Ohio, Wabash, Middle Mississippi, Upper Mississippi and Illinois rivers and to compare population demographics (recruitment, growth, and mortality) among rivers. Water samples were collected from each of the five rivers and their tributaries and analyzed for strontium, barium, and calcium concentrations to calculate molar elemental ratios (Sr:Ca, Ba:Ca) and determine if differences in water Sr:Ca and Ba:Ca observed in prior studies persisted among large rivers and their tributaries. Otoliths from White Bass collected from locations where their movement was constrained (e.g., impoundments where dam passage is not possible) were analyzed to characterize relationships between water chemistry (Sr:Ca and Ba:Ca) and White Bass otolith chemistry. I then applied these regression relationships in conjunction with water chemistry data from each of the five large rivers and tributaries in the study area to estimate ranges of otolith Sr:Ca and Ba:Ca for White Bass in each of the rivers and tributaries. Otolith core Sr:Ca and Ba:Ca from White Bass collected from the Ohio, Wabash, Middle Mississippi, Upper Mississippi, and Illinois rivers were compared with predicted river-specific ranges of otolith Sr:Ca and Ba:Ca to identify natal river for each fish. All fish utilized for microchemistry were aged and used to create an age-at-length key from which vital rate parameters were calculated. Microchemistry results indicated that White Bass origin proportions differed among rivers. In rivers with more prominent differences in water Sr:Ca compared to their tributaries and upstream river segments, natal river assignments were more definitive and indicated that large river White Bass stocks are being strongly supplemented by tributaries and other upriver locations. In areas with small differences in water chemistry among potential natal rivers, origin designations were less definitive due to partially overlapping ranges of Sr:Ca and Ba:Ca among locations. A study using genetics to assess natal river fidelity in spawning White Bass should be conducted to better assess stocks and population structure in the large rivers. White Bass populations were dominated by age 0 fish (young of the year). Vital rate parameters were consistent with those of reservoir populations in the central United States, with riverine White Bass exhibiting fast growth, high mortality, and variable recruitment. My results indicated that a holistic approach to large river management should be considered when managing White Bass. Management regulations should reflect those in well studied reservoir populations based upon my findings, but future projects should expand upon our data and focus on population modeling of White Bass in these systems to better understand fishing and natural mortality, especially in areas of concentrated fish during the spawning season.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 8 uppsatser.

Knowledge of natal environments and dispersal of Silver Carp (Hypophthalmichthys molitrix) inhabiting the Ohio River, and Kentucky and Barkley lakes would inform development of strategies to control established and emerging populations. However, the principal natal environments supporting the emerging bigheaded carp population in the Ohio River basin are unknown. There is also a need to assess the role of tributaries as nursery sites to increase understanding of dispersal patterns and better target young fish. The goal of this study was to identify recruitment sources and determine dispersal patterns of Silver Carp in the Ohio River basin using evidence from otolith core trace element compositions relative to ambient water elemental measurements. Fish were collected from the Ohio River, and Kentucky and Barkley lakes from 2014-2017 and water samples were taken during summer 2012-2017. Water samples maintained temporal stability and spatial differentiation for the Ohio River and tributaries during the sampling period. Results suggest that most Silver Carp in the Ohio River are utilizing tributaries during early life. Results also suggest there is passage of carp through the locks into the lakes from the Ohio River and natural reproduction is occurring in or above Kentucky and Barkley lakes. Results will inform development of efforts to target and remove spawning and young bigheaded carps as well as direct management efforts in the Tennessee and Cumberland River systems.

Rehabilitation of sturgeon populations requires an understanding of sturgeon autecology during all life stages, especially during early life when high mortality occurs. To begin to understand sturgeon early-life history I determined river of origin on a multi-basin scale (i.e., potential rivers of origin). I then determined habitat needs and early life demographics on a more localized scale (i.e., specific river). Trace elements differ between river reaches of the central US and may be used to determine origin of age-0 sturgeon. My trace element analyses suggested that age-0 sturgeon captured in the Middle Mississippi River, which extends from the confluence of the Missouri River downstream to the confluence of the Ohio River, drifted from as far upstream as the Gavins Point Dam on the Missouri River (> 1200 km), while other individuals originated locally in the Middle Mississippi River. On a more refined scale of habitats, I used trawling to identify habitat features used. Age-0 Scaphirhynchus sturgeon catch rates were highest around artificial structures (i.e., wing dikes) and island areas while main channel habitat comprised the lowest catch rates. Within these habitats, young sturgeon frequently occupied low velocities (i.e., ~0.1), moderate depths (i.e., 2 to 5 m), and sand substrate. Although determination of river of origin and specific habitats used are imperative for restoration, sturgeon populations are likely regulated by factors within habitats that affect early-life dynamics. Mean sturgeon growth rates ranged from 1.42-1.50 mm/d over the four years but did not differ among years. Individuals hatched over a 25 to 50-d period and peak hatch dates were between 10- 20 May during all years. Hatching coincided with optimum spawning temperatures of 17-20oC and a rise in river stage. Abundance was positively related to river stage, with longer durations of high water related increasing abundance. Mortality of age-0 sturgeon increased with the number of days where water temperature exceeded 28 oC. In the end this study has set benchmarks for understanding factors affecting the early-life ecology of Scaphirhynchus sturgeon.

Knowledge of environmental history is important for the management and conservation of fish populations. Multiple methods to tag or mark fish have been developed (e.g., radio transmitters, coded wire tags, PIT tags, genetic markers), however, each of these methods has limitations. Naturally occurring and artificial chemical markers in otoliths have recently been used to determine natal origins and environmental history of fishes in both marine and freshwater environments and are not subject to the shortcomings of conventional tagging methods. However, few studies have evaluated the application of fish fin rays as a non-lethal alternative to fish otoliths as a recorder of individual fish environmental history. Therefore, I evaluated the application of artificial and naturally occurring chemical markers in fish fin rays as tracers of individual environmental histories. Specifically, I sought to determine 1) if age-0 lake sturgeon pectoral fin rays could be marked by immersion in strontium carbonate (SrCO3) enriched with the stable isotope 86Sr (86SrCO3), 2) whether natural differences in otolith and fin spine chemistry are present in catfish species collected from the Mississippi River basin, and 3) whether natural differences in fin ray chemistry are present in smallmouth bass from different rivers and streams in northern Illinois. Results from the first objective indicated that age-0 lake sturgeon were marked with 83% success when reared in water enriched with 100 µg/L of 86SrCO3, compared to control fish, and mark retention was maintained for at least 120 d following the labeling period. Results of the second objective indicated that both catfish otolith Sr:Ca, δ18O, and δ13C and fin spine Sr:Ca differed among sites, reflecting geographic differences in water chemistry at source locations. Both structures classified fish to their environment of capture with a high degree of accuracy, except in the Middle and Lower Mississippi Rivers where many recent immigrants appeared to be present. Similarly, smallmouth bass fin ray core Sr:Ca differed among sites, reflecting previously documented differences in water chemistry among streams and rivers in northern Illinois. Classification accuracy of smallmouth bass to their environment of capture based on fin ray Sr:Ca was variable, as some rivers had similar water chemistry signatures. The use of artificial chemical marks in fin rays will be useful when marking small fish that may not respond well to physical tags, when non-lethal recovery is desirable, and to distinguish between multiple batches of stocked fish (i.e. to evaluate factors such as stocking location and timing, fish size, and when fish may become interspersed into the existing population). Natural chemical signatures in pectoral fin rays or fin spines may provide a non-lethal alternative to otoliths for gathering information on environmental history (e.g. stock mixing, recruitment sources) of smallmouth bass and catfishes, consistent with recent demonstrations of this technique's effectiveness in other fish species. Ultimately, the use of artificial and naturally occurring chemical marks in fish fin rays provides a non-lethal alternative method to evaluate the environmental history of all life stages of fish

Orientador: Fernando Galembeck / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T10:30:17Z (GMT). No. of bitstreams: 1 Rippel_MarciaMaria_D.pdf: 28336240 bytes, checksum: d54ace138d40b3edcabb2029aeef4d5e (MD5) Previous issue date: 2005 / Doutorado / Físico-Química / Doutor em Ciências

Oil from the Deepwater Horizon blowout reached the Gulf of Mexico coast in the summer of 2010 and potentially exposed species living in those areas to toxic chemicals. The purpose of this study is to examine otoliths from Red Drum (Sciaenops ocellatus) for evidence of oil exposure that could be related to reduced growth rates. Because otolith growth and somatic growth are directly related, differences in annulus measurements can indicate differences in annual somatic growth, which is a good indicator of overall fish condition, and translates into changes in survival and lifetime reproductive potential. This study assessed variation in otolith elemental composition in years before, during, and after the oil spill using laser-ablation inductively-coupled plasma mass spectrometry, with emphasis on trace metals previously found in MC252 oil. Relative annual growth rates were estimated by calculating mean increment measurements for each age, and calculating a percentile for each observation. Growth was then compared with otolith elemental profiles. These two analyses were used to investigate associations between any observed growth variation and the temporal profiles of oil-indicator and stress-indicator elements. Otoliths obtained from Florida archaeological sites were used as a baseline for pre-industrial elemental compositions. Fish taken from 12 sampling sites in Florida and Louisiana with varying degrees of oil intrusion were analyzed for otolith element composition. Individual measurements were classified using Similarity Profile Analysis (SIMPROF, Clarke et al. 2008) and resulting SIMPROF groups were plotted on a seriated heat map to visualize elemental abundance groups. The largest group with the lowest elemental abundances was used as a reference group. This group was compared to higher-element abundance groups and to fossil otoliths found in Native American middens on Weedon Island, FL using nonparametric multivariate analysis of variance (NP-MANOVA) and Canonical Analysis of Principal Coordinates (CAP) to determine similarities of modern fish groups and an ancient baseline. Growth rates were then compared to the microchemistry groups to determine if there are any correlations with growth rates and otolith trace metal compositions. This study did not find any correlation between the Deepwater Horizon oil spill event and either Red Drum otolith microchemistry or growth. Otolith oil-metal concentrations did not vary significantly among study years, and there was no relationship between microchemistry and otolith-based growth rate. While there was decreased growth in 2010, the decreased growth appeared to be due to unusually cold winters during that year. Oil metal concentrations measured in the otoliths indicated continuous metal exposure rather than exposure to an episodic oil-spill event. This study also verified the use of archaeological otoliths as a viable microchemical baseline for pre-industrial otoliths. Preserved otolith material had very low hydrocarbon-associated metal concentrations, which is expected in otoliths that were formed before the period of heavy anthropogenic influence on coastal waters. This study represents a novel effort to compare pre-industrial-age microchemistry to the microchemistry of fish collected from impacted areas following a large oil spill.

Like many native endemic desert freshwater fish species, the June Sucker (Chasmistes liorus) is currently listed as endangered. Managers have increasingly turned to habitat restoration as a key component to recovery plans. For endangered species, one of the primary outcomes of habitat restoration is that it should result in successful reproduction and recruitment of individuals into the adult population. Confirmation of natural recruitment as a function of habitat restoration can only be achieved by establishing natal origins. Recent research has proven the validity of otolith microchemistry, a technique that analyzes small quantities of elements, to trace potamodromous fish to their natal tributaries. Previous studies have documented that localized habitats in terms of microchemistry are reflected in otolith composition, thereby potentially making this a valuable way of determining fish origins. The primary goal of this study is to use otolith microchemistry to establish natal origins of June Sucker, ultimately in order to evaluate whether tributary habitat restoration results in natural recruitment. To accomplish this I first determined if the water chemistry among the three main spawning tributaries differed from one another. Second, I determined if the otolith chemistry reflected the otolith chemistry. Lastly, I developed a statistical model capable of classifying fish to their respective tributary based the element:calcium ratios in the otolith microchemistry. Water chemistry differed significantly among all three spawning tributaries, and I observed a strong and significant relationship between otolith chemistry and water chemistry. The classification models based on otolith element:Ca signatures were capable of accurately classifying individual fish to their natal tributary (classification tree 89% accuracy; random forest model 91% accuracy), increasing the ability to determine if the fish’s origin is wild vs. hatchery. The data obtained from this study will advance the current understanding of the June sucker recruitment dynamics and result in a fundamental improvement in our ability to determine where natural recruitment into the adult spawning population is occurring. In addition, this knowledge may help evaluate factors limiting recruitment in Utah Lake tributaries, identify future restoration localities, and assist effectiveness monitoring of spawning habitat restoration efforts.

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.

The focus of this work was on the use of otolith microchemistry and fish eye lens chemical profiles to measure fish movement and provided indirect support for the use of otolith microchemistry to examine exposure to crude oil. Chapter 1 provides an introduction to the applications of otolith microchemistry and eye lens isotopic profiles. In the second chapter, which examined associations between metal exposure and lesion formation in fishes collected after the Deepwater Horizon (DWH) oil spill, I did not observe any change in oil-associated metal concentrations in otoliths coinciding with the timing of the DWH oil spill. This suggests that either the technique used is not sensitive enough to detect any transient changes that may have occurred because of exposure to the oil spill or that the fish examined were not exposed to the oil spill. However, I did find that lesioned fish may have been exposed to a persistent source of trace-metals in the GoM prior to, during, and after the oil spill, and metal-induced immunomodulation may have occurred in these fish. These interactions between the physiological and environmental modulation of otolith element incorporation were explored further in Chapter 3 in which multiple tests demonstrated that physiology explained more of the variation in otolith chemical tags than ambient water chemistry. These findings suggest that the use of otolith microchemistry alone to track fish movement and potential exposure to harmful metals may be complicated by physiological control of otolith microchemistry. Thus, in Chapter 4, I pursued a novel method to evaluate the movement of fish across isoscapes of varying δ15N. I validated the use of fish eye lenses as potential lifetime recorders of isotopic histories and in Chapter 5 compared the use of fish eye lens δ15N profiles to otolith microchemistry profiles to examine fish movement. Both techniques suggested similar patterns of movement in Red Snapper from the northern GoM to the West Florida Shelf. This is the first study to use these complimentary techniques to track fish movement.