@article{henson_aday_rice_layman_2018, title={Assessing the Influence of Tilapia on Sport Fish Species in North Carolina Reservoirs}, volume={147}, ISSN={["1548-8659"]}, DOI={10.1002/tafs.10031}, abstractNote={AbstractRedbelly Tilapia Tilapia zilli and Blue Tilapia Oreochromus aureus are indigenous to Africa and the Middle East, but now occur throughout the southeastern United States. It is fairly well understood that foraging flexibility and wide salinity, oxygen, and temperature tolerances have led to general invasion success for most tilapia species. Conflicting empirical information about the influence of tilapia on native sport fish species, however, leaves natural resource managers unable to anticipate and prevent further introductions and potential associated risks to native sport fishes. This investigation focused on two North Carolina reservoirs with tilapia populations: Hyco Lake, a large reservoir in northcentral North Carolina and Lake Julian, a small impoundment in western North Carolina. These reservoirs receive heated effluent from power generation, which is assumed to provide winter refuge for tilapia at a time when temperatures would otherwise lead to mortality. We assessed relative abundances of the tilapias and native sport species (Bluegill Lepomis macrochirus, black basses Micropterus spp., and Black Crappie Pomoxis nigromaculatus) in these systems and examined their trophic interactions via diet and stable isotope analyses in both lakes. In Hyco Lake we assessed potential spatial interactions and influences on relative abundance using a priori candidate models and model selection via Akaike's information criterion (AIC). These analyses indicated little evidence of tilapias influencing the relative abundances of the sport species in Hyco Lake. In both lakes, however, we did find substantial diet overlap between the tilapias and Bluegill along with isotopic niche overlap between Blue Tilapia and Bluegill in Lake Julian and Redbelly Tilapia and Bluegill in Hyco Lake. Due to the omnivorous and flexible diet of all three species these interactions were not surprising, but the ultimate influence on Bluegill growth and size structure is unknown. Overall, our results suggest that tilapia are exploiting trophic niches that are not used by the sport fishes of interest in these two very different reservoir systems and that their direct impact on sport species is not substantial.}, number={2}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Henson, Mary Nell and Aday, D. Derek and Rice, James A. and Layman, Craig A.}, year={2018}, month={Mar}, pages={350–362} }
 @article{bradley_rice_aday_2018, title={Modeling the Effects of Vital Rate Manipulation and Management Scenarios to Predict the Population Impact of Restoration Programs on an Unrecovered Coastal Population of Striped Bass}, volume={38}, ISSN={["1548-8675"]}, DOI={10.1002/nafm.10062}, abstractNote={AbstractStriped Bass Morone saxatilis have supported important fisheries along the Atlantic coast of North America. However, the species experienced major declines due to overharvest, water quality degradation, and dam construction. Restoration efforts have been successful for specific stocks but unsuccessful for the Striped Bass population in the Neuse River of North Carolina. Ongoing research programs have estimated stage‐ and source‐specific mortality rates to identify mechanisms associated with the lack of recovery of the population. These demographic data are useful; however, they give little insight into the effectiveness of potential restoration programs. To develop effective management strategies, we used estimated mortality rates from the literature to build an age‐structured population model. We estimated that if vital rates remained constant, the Neuse River adult Striped Bass population would consist of 18,457 individuals (95% credible interval = 8,176–34,314). We then conducted a life stage simulation analysis to determine the adult population abundance and age structure that would result from a 50% decrease of the following: juvenile and adult natural mortality, recreational discard and harvest, and commercial discard and harvest. Finally, we simulated the potential impacts of six possible management scenarios on population abundance and age structure. We determined that the abundances of adults (age 3+) and older adults (age 6+) were most sensitive to natural mortality of juveniles and adults and next most sensitive to commercial harvest and discard. We further estimated that eliminating all fishing mortality would have the greatest impact on the population and would result in a 26‐fold increase in abundance of age‐6+ adults. Our results suggest that high mortality rates are preventing the development of a sufficient abundance of adult spawning stock. We recommend that managers use this model to identify the most effective management scenario—given specific goals and constraints—to help increase Striped Bass abundance in the Neuse River.}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Bradley, Caitlin E. and Rice, James A. and Aday, D. Derek}, year={2018}, month={Jun}, pages={639–649} }
 @article{grieshaber_penland_kwak_cope_heise_law_shea_aday_rice_kullman_et al._2018, title={Relation of contaminants to fish intersex in riverine sport fishes}, volume={643}, ISSN={0048-9697}, url={http://dx.doi.org/10.1016/J.SCITOTENV.2018.06.071}, DOI={10.1016/j.scitotenv.2018.06.071}, abstractNote={Endocrine active compounds (EACs) are pollutants that have been recognized as an emerging and widespread threat to aquatic ecosystems globally. Intersex, the presence of female germ cells within a predominantly male gonad, is considered a biomarker of endocrine disruption caused by EACs. We measured a suite of EACs and assessed their associated impacts on fish intersex occurrence and severity in a large, regulated river system in North Carolina and South Carolina, USA. Our specific objective was to determine the relationship of contaminants in water, sediment, and fish tissue with the occurrence and severity of the intersex condition in wild, adult black bass (Micropterus), sunfish (Lepomis), and catfish (Ictaluridae) species at 11 sites located on the Yadkin-Pee Dee River. Polycyclic aromatic hydrocarbons (PAHs), ethinylestradiol (EE2), and heavy metals were the most prevalent contaminants that exceeded effect levels for the protection of aquatic organisms. Fish intersex condition was most frequently observed and most severe in black basses and was less frequently detected and less severe in sunfishes and catfishes. The occurrence of the intersex condition in fish showed site-related effects, rather than increasing longitudinal trends from upstream to downstream. Mean black bass and catfish tissue contaminant concentrations were higher than that of sunfish, likely because of the latter's lower trophic position in the food web. Principal component analysis identified waterborne PAHs as the most correlated environmental contaminant with intersex occurrence and severity in black bass and sunfish. As indicated by the intersex condition, EACs have adverse but often variable effects on the health of wild sport fishes in this river, likely due to fluctuations in EAC inputs and the dynamic nature of the riverine system. These findings enhance the understanding of the relationship between contaminants and fish health and provide information to guide ecologically comprehensive conservation and management decisions.}, journal={Science of The Total Environment}, publisher={Elsevier BV}, author={Grieshaber, C.A. and Penland, T.N. and Kwak, T.J. and Cope, W.G. and Heise, R.J. and Law, J.M. and Shea, Damian and Aday, D.D. and Rice, J.A. and Kullman, S.W. and et al.}, year={2018}, month={Dec}, pages={73–89} }
 @article{aday_daugherty_murie_2018, title={Renewing the Vision for AFS Journals}, volume={43}, ISSN={["1548-8446"]}, DOI={10.1002/fsh.10163}, abstractNote={FisheriesVolume 43, Issue 10 p. 460-462 Column: AFS News Renewing the Vision for AFS Journals D. Derek Aday, D. Derek Aday ddaday@ncsu.edu Department of Applied Ecology, North Carolina State University, 127 David Clark Laboratory, Raleigh, NC, 27695 Search for more papers by this authorDaniel J. Daugherty, Daniel J. Daugherty Texas Parks and Wildlife Department, Heart of the Hills Fisheries Science Center, Mountain Home, TXSearch for more papers by this authorDebra J. Murie, Debra J. Murie School of Forest Resources and Conservation, Fisheries and Aquatic Sciences Program, University of Florida, Gainesville, FLSearch for more papers by this author D. Derek Aday, D. Derek Aday ddaday@ncsu.edu Department of Applied Ecology, North Carolina State University, 127 David Clark Laboratory, Raleigh, NC, 27695 Search for more papers by this authorDaniel J. Daugherty, Daniel J. Daugherty Texas Parks and Wildlife Department, Heart of the Hills Fisheries Science Center, Mountain Home, TXSearch for more papers by this authorDebra J. Murie, Debra J. Murie School of Forest Resources and Conservation, Fisheries and Aquatic Sciences Program, University of Florida, Gainesville, FLSearch for more papers by this author First published: 04 September 2018 https://doi.org/10.1002/fsh.10163Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume43, Issue10October 2018Pages 460-462 RelatedInformation}, number={10}, journal={FISHERIES}, author={Aday, D. Derek and Daugherty, Daniel J. and Murie, Debra J.}, year={2018}, month={Oct}, pages={460–462} }
 @article{bradley_rice_aday_hightower_rock_lincoln_2018, title={Juvenile and Adult Striped Bass Mortality and Distribution in an Unrecovered Coastal Population}, volume={38}, ISSN={["1548-8675"]}, DOI={10.1002/nafm.10036}, abstractNote={AbstractStriped Bass Morone saxatilis fisheries have been important in the eastern United States since the 1700s, but many populations have declined from historic levels. Enhancement programs, harvest reduction, water quality improvements, and habitat restoration have led to successful recoveries for specific stocks. However, these efforts have not been successful for the Striped Bass population in the Neuse River of North Carolina. Possible mechanisms inhibiting recovery of this population include overharvest, high discard mortality, poor water quality, and altered flow regimes. These mechanisms and their impacts on the Neuse River population are unclear; therefore, to gain insight, we estimated mortality and distribution of the population. Specifically, we tagged 100 hatchery‐reared phase II juveniles (202–227 mm TL) and 111 resident adults (349–923 mm TL) with acoustic transmitters (a subset of 50 adults was also tagged with external high‐reward tags). We used telemetry to monitor movement and seasonal distribution from December 2013 until September 2015. Telemetry and tag reporting data informed mortality models, and we estimated that annual discrete total mortality of phase II stocked juveniles was 66.3% (95% credible interval [CI] = 47.4–82.4%). Annual discrete total mortality of adults was 54.0% (95% CI = 41.5–65.4%). Adult discrete natural mortality was 20.1% (95% CI = 8.7–39.1%), and neither juvenile nor adult natural mortality was correlated with seasonal variation in dissolved oxygen, temperature, or salinity. These results show that poststocking mortality is significant and that juvenile mortality should be considered when establishing stocking goals. Additionally, adult natural mortality is within the range predicted by maximum age and by previous studies; however, adult total mortality is higher than targeted rates. These results can help to inform management decisions and develop measures to rebuild depressed Striped Bass populations like that in the Neuse River.}, number={1}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Bradley, Caitlin E. and Rice, James A. and Aday, D. Derek and Hightower, Joseph E. and Rock, Jason and Lincoln, Kelsey L.}, year={2018}, month={Feb}, pages={104–119} }
 @article{owensby_rice_aday_2017, title={Mortality, Dispersal, and Habitat Use of Stocked Juvenile Muskellunge in Two Western North Carolina Rivers}, volume={37}, ISSN={["1548-8675"]}, DOI={10.1080/02755947.2016.1245222}, abstractNote={AbstractThe Muskellunge Esox masquinongy is a highly sought‐after sport fish that is native to the Tennessee River drainage of western North Carolina. After the extirpation of Muskellunge from North Carolina in the 1950s, the North Carolina Wildlife Resources Commission began a stocking program to re‐establish the species and produce viable Muskellunge fisheries in North Carolina. Although stocking efforts have created a Muskellunge fishery in, for example, the French Broad River (where the species was native), there is little evidence of success in North Carolina sections of the New River (where the species was not native). Possible mechanisms inhibiting stocking success are unclear because there is relatively little information available on the juvenile life stage of the Muskellunge, especially in the southern portion of its distribution. We addressed the perceived differences in recruitment between the two fisheries by using telemetry to investigate dispersal, mortality, and habitat use by stocked juvenile Muskellunge. Fifty hatchery‐reared, age‐0 Muskellunge (282–307 mm TL) were tagged prior to stocking in the New River (fall 2013) and French Broad River (fall 2014). Three months after stocking, known survival of tagged fish was 4% in the New River and 29% in the French Broad River; the survival probability after 3 months was estimated at 9% (range = 4–17%) in the New River and 37% (range = 25–56%) in the French Broad River. Extended survival in the French Broad River was 14% at 252 d poststocking. High dispersal was observed, with maximum individual dispersal of 67.4 km in the New River and 55.5 km in the French Broad River. Habitat suitability analyses indicated that juvenile Muskellunge in the FBR selected shallow nearshore areas with low water velocity, fine substrate, and substantial cover in the form of woody debris and overhanging vegetation. Information on the survival and behavior of stocked Muskellunge can facilitate efforts to successfully manage these fisheries.Received December 4, 2015; accepted October 3, 2016Published online January 3, 2017}, number={1}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Owensby, Dylan P. and Rice, James A. and Aday, D. Derek}, year={2017}, pages={108–121} }
 @article{henson_aday_rice_2018, title={Thermal Tolerance and Survival of Nile Tilapia and Blue Tilapia under Rapid and Natural Temperature Declination Rates}, volume={147}, ISSN={["1548-8659"]}, DOI={10.1002/tafs.10023}, abstractNote={AbstractBlue Tilapia Oreochromis aureus and Nile Tilapia O. niloticus are indigenous to Africa and the Middle East but now are globally popular in aquaculture and for private and public stocking as forage fish for sport species and biological control for nuisance vegetation. The invasive nature of these species at a global scale and the lack of recent and applicably tested thermal tolerance methodology require research to assess the current potential for invasion risk in North Carolina and elsewhere. In this thermal tolerance experiment we focused on a moderate declination rate (1°C per 3 d) and a slow declination rate (1°C per week) in water temperature to assess the thermal minima of Blue Tilapia, common Nile Tilapia, and a “white” strain of Nile Tilapia. The moderate rate was used to compare results to previous literature, and the slow rate was used to mimic natural seasonal water temperature decline in North Carolina. As lineage and breeding history may vary by supplier, fish from multiple suppliers within each species group were tested. Our results indicate that in general, these tilapias cannot survive below 8°C. We did not observe differences in temperature at death or survival curves between species in the moderate rate treatment. Under the slow declination rate, we found significant differences in the mean temperatures at death of Blue Tilapia (9.5°C) and white Nile Tilapia (9.3°C) relative to the less‐cold‐tolerant common Nile Tilapia (10.8°C); this result was reflected in statistically different survival curves. In addition, although there was some variation in temperature at death among different supplier groups (0.0–0.6°C) within a species, all fish died at 8°C or above. Our results suggest that selective breeding of white Nile Tilapia may have resulted in increased thermal tolerance during the process of developing this color variant. Furthermore, the minimum lethal temperature of 8°C may explain why these tilapia species have been restricted to reservoirs with heated effluent in North Carolina.}, number={2}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Henson, Mary Nell and Aday, D. Derek and Rice, James A.}, year={2018}, month={Mar}, pages={278–286} }
 @article{lee pow_tilahun_creech_law_cope_kwak_rice_aday_kullman_2017, title={Windows of Susceptibility and Consequences of Early Life Exposures to 17β–estradiol on Medaka (Oryzias latipes) Reproductive Success}, volume={51}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/ACS.EST.7B01568}, DOI={10.1021/acs.est.7b01568}, abstractNote={Estrogens and estrogen mimics are commonly found in surface waters and are associated with deleterious effects in fish populations. Impaired fertility and fecundity in fish following chronic exposures to estrogens and estrogen mimics during critical windows in development are well documented. However, information regarding differential reproductive effects of exposure within defined developmental stages remains sparse. In this study, reproductive capacity was assessed in Japanese medaka (Oryzias latipes) after exposure to two concentrations of 17β-estradiol (E2β; 2 ng/L and 50 ng/L) during four distinct stages of development: gonad development, gonad differentiation, development of secondary sex characteristics (SSC) and gametogenesis. Exposure to E2β did not adversely impact survival, hatch success, growth, or genotypic ratios. In contrast, exposure to 50 ng/L E2β during SSC development altered phenotypic ratios and SSC. Exposure to both E2β treatments reduced reproductive capacity (fertility, fecundity) by 7.3-57.4% in adult medaka breeding pairs, with hindrance of SSC development resulting in the largest disruption in breeding capacity (51.6-57.4% decrease) in the high concentration. This study documents differential effects among four critical stages of development and provides insight into factors (window of exposure, exposure concentration and duration of exposure period) contributing to reproductive disruption in fish.}, number={9}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Lee Pow, Crystal S.D. and Tilahun, Kedamawit and Creech, Kari and Law, J. Mac and Cope, W. Gregory and Kwak, Thomas J. and Rice, James A. and Aday, D. Derek and Kullman, Seth W.}, year={2017}, month={Apr}, pages={5296–5305} }
 @article{lee pow_law_kwak_cope_rice_kullman_aday_2017, title={Endocrine active contaminants in aquatic systems and intersex in common sport fishes}, volume={36}, ISSN={0730-7268}, url={http://dx.doi.org/10.1002/ETC.3607}, DOI={10.1002/ETC.3607}, abstractNote={AbstractMale fish are susceptible to developing intersex, a condition characterized by the presence of testicular oocytes. In the present study, the relationship between intersex and exposure to estrogenic endocrine active contaminants (EACs) was assessed for 2 genera of sport fish, Micropterus and Lepomis, at 20 riverine sites. Seasonal trends and relationships between EACs and intersex (prevalence and severity) were examined at varying putative sources of EACs throughout North Carolina, identified as point sources, nonpoint sources, and reference sites. Intersex was identified in both genera, which was documented for the first time in wild‐caught Lepomis. Intersex was more prevalent (59.8%) and more severe (1.6 mean rank) in Micropterus, which was highly correlation to EACs in sediment. In contrast, intersex was less common (9.9%) and less severe (0.2 mean rank) in Lepomis and was highly correlated to EACs in the water column. The authors found that concentrations of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, industrial EACs, and estrogens were highest at point source sites; however, no source type variation was identified in the prevalence or severity of intersex, nor were there seasonal trends in intersex or EAC concentrations. The authors’ results associate genus‐specific prevalence of intersex with specific EAC classes in common sport fishes having biological, ecological, and conservation implications. Environ Toxicol Chem 2017;36:959–968. © 2016 SETAC}, number={4}, journal={Environmental Toxicology and Chemistry}, publisher={Wiley}, author={Lee Pow, Crystal S.D. and Law, J. Mac and Kwak, Thomas J. and Cope, W. Gregory and Rice, James A. and Kullman, Seth W. and Aday, D. Derek}, year={2017}, month={Apr}, pages={959–968} }
 @article{lincoln_aday_rice_2016, title={Seasonal Mortality and Movement Patterns of White Bass in a Southeastern US Reservoir}, volume={145}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2016.1195444}, abstractNote={AbstractLittle is known about the fundamental aspects of the life history, ecology, and population dynamics of White Bass Morone chrysops in southern U.S. reservoirs, making management of this species difficult. Recent concerns from the North Carolina Wildlife Resources Commission regarding potential population declines in North Carolina prompted an effort to expand the knowledge base of White Bass in reservoirs. Our study aimed to address mortality (fishing mortality, F, and natural mortality, M) as one potential mechanism related to their population declines and to assess seasonal movement and habitat patterns of reservoir White Bass throughout the year using telemetry. We implanted acoustic transmitters into 50 White Bass in spring 2012 and into 25 White Bass in spring 2013. B. Everett Jordan Reservoir, a relatively shallow and eutrophic reservoir located in the Piedmont region of North Carolina, was separated into four different subbasins that were surveyed each month for tagged fish. Fish were monitored using an array of passive receivers and monthly active tracking surveys. A monthly capture history was used as the input for a multistate capture–recapture model in a Bayesian framework to estimate instantaneous monthly mortality rates. Total annual mortality was 76%. The annual exploitation rate (60%) was greater than the natural mortality rate (15%); however, both F and M exhibited seasonal variation and peaked during spring months in 2012 and 2013. White Bass did not use any specific habitat type but were located relatively far from shore and in deep water during cooler months. The use of subbasins in the system was not equal; other than during the spawning run White Bass concentrated in several areas within the two deepest subbasins of the reservoir. Overall, the high F observed in the spring suggests that adjusting the current liberal harvest limits will help mitigate mortality and aid in the management of reservoir White Bass populations.Received January 21, 2016; accepted May 4, 2016 Published online August 5, 2016}, number={5}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Lincoln, Kelsey J. and Aday, D. Derek and Rice, James A.}, year={2016}, pages={1035–1046} }
 @article{pow_yost_aday_kullman_2016, title={Sharing the Roles: An Assessment of Japanese Medaka Estrogen Receptors in Vitellogenin Induction}, volume={50}, ISSN={["1520-5851"]}, DOI={10.1021/acs.est.6b01968}, abstractNote={Teleost fish express at least three estrogen receptor (ER) subtypes. To date, however, the individual role of these ER subtypes in regulating expression of estrogen responsive genes remains ambiguous. Here, we investigate putative roles of three ER subtypes in Japanese medaka (Oryzias latipes), using vitellogenin (VTG) I and II as model genes. We identify specific ligand/receptor/promoter dynamics, using transient transactivation assays that incorporate luciferase reporters comprising 3kb promoter/enhancer regions of medaka VTGI and VTGII genes. Four steroidal estrogens (17β-estradiol, estrone, estriol, and 17α-estradiol) were tested in these assays. Results indicate that all three medaka ERs (mERs) are capable of initiating transactivation of both VTG I and II, with ERβ2 exhibiting greatest activity. Promoter deletion analysis suggests that ligand-specific receptor transactivation and utilization of regional-specific estrogen response elements may be associated with differential activities of each medaka ER. Further, cluster analysis of in vivo gene expression and in vitro transactivation suggests that all three ER subtypes putatively play a role in up-regulation of VTG. Results illustrate that preferential ligand/receptor/promoter interactions may have direct implications for VTG gene expression and other ER-mediated regulatory functions that are relevant to the risk assessment of estrogenic compounds.}, number={16}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Pow, Crystal S. D. Lee and Yost, Erin E. and Aday, D. Derek and Kullman, Seth W.}, year={2016}, month={Aug}, pages={8886–8895} }
 @article{brown_rice_suski_aday_2015, title={Dispersal Patterns of Coastal Largemouth Bass in Response to Tournament Displacement}, volume={35}, ISSN={["1548-8675"]}, DOI={10.1080/02755947.2015.1009660}, abstractNote={AbstractTournament displacement, stockpiling near release points, and handling stress are major concerns for managers of sport fisheries in the southeastern USA. We examined the effects of transport distance and tournament handling stress on dispersal of 40 Largemouth Bass Micropterus salmoides via telemetry from May 2012 to September 2013 in the Albemarle Sound system of eastern North Carolina. Largemouth Bass were captured from four tributaries of Albemarle Sound and transported 16.5–45 km to a central release point before being acoustically tagged and released. Movement data from an array of passive receivers was used to calculate rates of dispersal from the release point, emigration from the study area and return to capture location over time. Blood cortisol concentration, collected from our tagged Largemouth Bass and those captured in an actual tournament, was used to determine the effect of stress on potential postrelease movement and survival. Our findings indicate little evidence of long‐term stockpiling (i.e., fish remaining close to release point; Richardson‐Heft et al. 2000); 57% of displaced Largemouth Bass dispersed more than 500 m from the release point within 7 d and 87% within 21 d postrelease. Half of those that emigrated from Edenton Bay returned to their capture location. However, no Largemouth Bass displaced 35–45 km returned to their capture locations, suggesting that long‐distance displacement inhibits return. Fishing (2.8%) and nonharvest mortality (0.5%) were low throughout this study except for peaks observed during late spring (42.9%) and early summer (25.1%) of 2013. Mean cortisol concentrations were similar in Largemouth Bass collected during our simulated tournament (126.7 ng/mL) and an actual tournament (118.4 ng/mL). However, cortisol concentrations were unrelated to survival, postrelease dispersal, or return of tagged individuals to their capture location. Largemouth Bass appear to be able to cope with current tournament practices; however, restrictions on displacement distance may increase return rates.Received August 26, 2014; accepted January 14, 2015}, number={3}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Brown, Daniel T. and Rice, James A. and Suski, Cory D. and Aday, D. Derek}, year={2015}, pages={431–439} }
 @article{brown_aday_rice_2015, title={Responses of Coastal Largemouth Bass to Episodic Hypoxia}, volume={144}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2015.1024801}, abstractNote={AbstractThe river systems inhabited by coastal populations of Largemouth Bass Micropterus salmoides in North Carolina and along the Atlantic and Gulf coast regions exhibit episodic (i.e., several times per year) fluctuations in environmental conditions (e.g., dissolved oxygen [DO]). Laboratory studies have documented the effects of low DO (hypoxia) on Largemouth Bass, yet few field studies have examined these effects in open systems. The objective of this study was to determine the effects of episodic hypoxia on Largemouth Bass distribution, survival, and feeding success in an open coastal system. We collected 45 Largemouth Bass from four tributaries of the Chowan River and tagged them with acoustic transmitters. Fish movements were monitored using active tracking and passive receivers, and these data were compared with DO levels recorded in the tributaries and main‐stem Chowan River. We found that tagged Largemouth Bass exhibited avoidance behavior at DO concentrations below 1.8 mg/L, with some seeking higher DO in the main stem or near tributary mouths during hypoxic events in the tributaries. The natural mortality rate of Largemouth Bass was low compared with rates reported in other studies, indicating that Largemouth Bass in coastal systems are able to survive hypoxic events. Analysis of stomach contents collected during hypoxic and non‐hypoxic periods indicated that Largemouth Bass had less food in their stomachs under hypoxic conditions; however, the CPUE (fish/h of pedal time) of potential prey fishes was not lower during hypoxic periods relative to non‐hypoxic periods, and thus a change in foraging opportunities did not appear to drive Largemouth Bass movement.}, number={4}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Brown, Daniel T. and Aday, D. Derek and Rice, James A.}, year={2015}, pages={655–666} }
 @article{sackett_pow_rubino_aday_cope_kullman_rice_kwak_law_2015, title={Sources of endocrine-disrupting compounds in North Carolina waterways: A geographic information systems approach}, volume={34}, ISSN={0730-7268}, url={http://dx.doi.org/10.1002/ETC.2797}, DOI={10.1002/etc.2797}, abstractNote={AbstractThe presence of endocrine‐disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17β‐estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17β‐estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17β‐estradiol levels than reference sites. The results suggested that water 17β‐estradiol was reflective of GIS predictions, confirming the relevance of landscape‐level influences on water quality and validating the GIS approach to characterize such relationships. Environ Toxicol Chem 2014;9999:1–9. © 2014 SETAC}, number={2}, journal={Environmental Toxicology and Chemistry}, publisher={Wiley}, author={Sackett, Dana K. and Pow, Crystal Lee and Rubino, Matthew J. and Aday, D. Derek and Cope, W. Gregory and Kullman, Seth and Rice, James A. and Kwak, Thomas J. and Law, Mac}, year={2015}, month={Jan}, pages={437–445} }
 @article{sackett_aday_rice_cope_2013, title={Maternally transferred mercury in wild largemouth bass, Micropterus salmoides}, volume={178}, ISSN={0269-7491}, url={http://dx.doi.org/10.1016/J.ENVPOL.2013.03.046}, DOI={10.1016/j.envpol.2013.03.046}, abstractNote={Maternal transfer of mercury in fish represents a potential route of elimination for adult females and a risk to developing embryos. To better quantify maternal transfer, we measured Hg in female largemouth bass (Micropterus salmoides) muscle and eggs from six waterbodies. Mercury in eggs from two waterbodies exceeded a US federal screening level (0.3 μg g(-1)) and was likely high enough to cause adverse reproductive effects. We found a curvilinear relationship between female and egg Hg. Fish with <0.37 μg g(-1) Hg had low levels of Hg in eggs; those with Hg >0.37 μg g(-1) showed a direct relationship between egg and muscle Hg (Log10 egg Hg = -1.03 + 1.18 * log10 muscle tissue Hg + 2.15 * (log10 muscle tissue Hg + 0.35)(2)). We also report higher maternal transfer (0.2-13.2%) and higher ratios of egg to muscle tissue Hg (4-52%) and egg to whole body Hg concentrations (7-116%) than previously observed for teleost fish.}, journal={Environmental Pollution}, publisher={Elsevier BV}, author={Sackett, Dana K. and Aday, D. Derek and Rice, James A. and Cope, W. Gregory}, year={2013}, month={Jul}, pages={493–497} }
 @article{sackett_cope_rice_aday_2013, title={The Influence of Fish Length on Tissue Mercury Dynamics: Implications for Natural Resource Management and Human Health Risk}, volume={10}, ISSN={["1660-4601"]}, url={https://doi.org/10.3390/ijerph10020638}, DOI={10.3390/ijerph10020638}, abstractNote={Consumption of fish has well-known human health benefits, though some fish may contain elevated levels of mercury (Hg) that are especially harmful to developing children. Fish length is most often the basis for establishing fishery harvest regulations that determine which fish will ultimately be consumed by humans. It is, therefore, essential to quantify the relationship between fish length and Hg accumulation in regard to harvest regulations for effective fishery and public health policy. We examined this relationship for three sportfish from six lakes across North Carolina, USA. Bluegill (Lepomis macrochirus) had the lowest Hg levels and only the very largest fish in the most contaminated site exceeded the US Environmental Protection Agency (USEPA) Hg screening level. Black crappie (Pomoxis nigromaculatus) had an intermediate level of Hg and larger individuals exceeded the USEPA screening level; however, they tended not to exceed this level before reaching the harvest length limit. Largemouth bass (Micropterus salmoides) exceeded the USEPA screening level at sizes below the fishery length limit in two lakes, leaving only higher risk fish for anglers to harvest and consume. Removing the effects of fish age and trophic position, we found strong positive correlations between Hg and fish length for largemouth bass and black crappie. We suggest public health officials and wildlife managers collaborate to structure fishery regulations and length-based fish consumption advisories that protect consumers from Hg exposure and communicate the relative risk of fish consumption.}, number={2}, journal={INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH}, author={Sackett, Dana K. and Cope, W. Gregory and Rice, James A. and Aday, D. Derek}, year={2013}, month={Feb}, pages={638–659} }
 @article{feiner_rice_bunch_aday_2013, title={Trophic Niche and Diet Overlap between Invasive White Perch and Resident White Bass in a Southeastern Reservoir}, volume={142}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2013.788563}, abstractNote={AbstractThe White Bass Morone chrysops is a popular sport fish that appears to be negatively affected by invasions of White Perch M. americana and often declines or disappears from invaded systems. In 2008, the first discovery of White Perch in Lake James, North Carolina, provided a rare opportunity to investigate trophic overlap between White Perch and a robust population of White Bass near the onset of invasion. We investigated the potential for resource competition between White Perch and White Bass by assessing their relative abundance (CPUE), trophic position, niche size, diet breadth, and diet overlap across 2 years. White Perch were more abundant than White Bass and had wider diet breadth and trophic niche size across seasons. White Perch also occupied lower trophic positions than White Bass, indicating that White Bass maintain a more piscivorous diet. However, diet and stable isotope analysis showed a high overlap between juvenile White Bass and all sizes of White Perch. Thus, juvenile White Bass may be susceptible to competition with White Perch where resources are limited. Therefore, biologists should take steps to prevent White Perch introductions into systems with popular White Bass fisheries.}, number={4}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Feiner, Zachary S. and Rice, James A. and Bunch, Aaron J. and Aday, D. Derek}, year={2013}, month={Jul}, pages={912–919} }
 @article{feiner_rice_aday_2013, title={Trophic Niche of Invasive White Perch and Potential Interactions with Representative Reservoir Species}, volume={142}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2013.763854}, abstractNote={AbstractThe trophic dynamics of invasive species can yield insights into the mechanisms of invasion success and aid in the prediction of potential impacts on established species. Additionally, the predicted effects of an invader may differ depending on how it integrates into the resident food web and whether its resource use changes throughout the invasion process. We investigated the trophic dynamics of populations of invasive White Perch Morone americana in three large North Carolina reservoirs and evaluated the potential for impacts on members of the resident fish community. Specifically, we used stable isotope and diet analyses to evaluate their trophic niche relative to three representative species in each reservoir chosen for their widespread range, potential overlaps with White Perch, recreational value, and representation of ecological guilds based on habitat and prey sources. The species were a native littoral generalist invertivore (Bluegill Lepomis macrochirus), native littoral piscivore (Largemouth Bass Micropterus salmoides), and stocked pelagic piscivore (Striped Bass Morone saxatilis or Walleye Sander vitreus, depending on their availability). Small (<70 mm TL), medium (120–170 mm TL), and large (>200 mm TL) White Perch occupied different trophic positions, and these positions were generally consistent among reservoirs relative to the representative species. Small and medium White Perch had the largest niche areas and high diet overlap with Bluegill in two of three lakes, whereas large White Perch had moderate diet overlap with Striped Bass, Largemouth Bass, and Walleye. As a species, White Perch occupy a wide trophic niche, which may aid in successfully establishing invasive populations. However, White Perch use resources shared by other members of the fish community, which could lead to negative impacts on these species.}, number={3}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Feiner, Zachary S. and Rice, James A. and Aday, D. Derek}, year={2013}, month={May}, pages={628–641} }
 @article{sackett_aday_rice_cope_2013, title={Validation of a Predictive Model for Fish Tissue Mercury Concentrations}, volume={142}, ISSN={["0002-8487"]}, DOI={10.1080/00028487.2012.747990}, abstractNote={AbstractIn an effort to reconcile the extensive variability in fish tissue mercury (Hg) in North Carolina, we previously created a predictive model using data collected from 1990 to 2006. Our model identified four factors—fish trophic status, fish species, ecoregion, and water pH—that explained 81% of the variation in fish tissue Hg. Herein, we evaluate the performance of this model by using two independently collected data sets describing fish tissue Hg in North Carolina and Virginia. Our model explained 75% of the variation in independently collected tissue Hg data from North Carolina and 68% of the variation in data collected from the same ecoregion types in Virginia. Although the relationships were relatively strong, the model generally underestimated observed tissue Hg. Residual analysis indicated that at least some of the model bias was due to error in predictions for sites near (within 10 km of) coal‐fired power plants. The model was not significantly biased when sites near power plants were removed from the independent data set, suggesting that the model was best at predicting mean tissue Hg in adult fish collected from water bodies greater than 10 km from power plants; such sites constitute the majority of the landscape. Fortuitously, fish at sites near power plants have significantly less tissue Hg than fish at sites far from power plants and are therefore of less concern to public health officials. The validated model can serve as a fish tissue Hg screening tool for use by state and federal agencies because it was created to predict Hg levels in numerous species and systems, and it only requires data that are readily available or relatively simple and inexpensive to measure. Identification of specific systems that may have highly contaminated fish and would not otherwise be sampled due to limited resources will help to focus sampling and enhance efforts to protect fish consumers.}, number={2}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Sackett, Dana K. and Aday, D. Derek and Rice, James A. and Cope, W. Gregory}, year={2013}, month={Mar}, pages={380–387} }
 @article{bethke_rice_aday_2014, title={White Perch in Small North Carolina Reservoirs: What Explains Variation in Population Structure?}, volume={143}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2013.830989}, abstractNote={AbstractWhite Perch Morone americana have been introduced into many inland systems throughout the United States. To determine factors affecting White Perch abundance and size structure, we compared White Perch growth, timing of maturity, and trophic level; the abundance of a predator (Largemouth Bass Micropterus salmoides); the abundance of an ecologically significant mid‐level omnivore (Gizzard Shad Dorosoma cepedianum); prey availability (chironomid and zooplankton abundances); and environmental variables (specific conductivity, Secchi depth, dissolved oxygen concentration, and temperature) among four reservoirs (two with high White Perch abundance and two with low abundance). White Perch size structure was closely tied to abundance, with truncated size structure as abundance increased. Among the other variables we tested, only Largemouth Bass abundance had a significant (negative) relationship with White Perch abundance. White Perch size structure appeared to be highly density dependent, and variables that commonly explain variation in abundance of introduced fishes did not explain differences in the four White Perch populations we studied. Further study of the competitive and predatory interactions of White Perch and Largemouth Bass over ontogeny could shed light on the mechanism(s) potentially shaping population structure of the two species where they coexist.}, number={1}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Bethke, Bethany J. and Rice, James A. and Aday, D. Derek}, year={2014}, month={Jan}, pages={77–84} }
 @article{petre_sackett_aday_2012, title={Do national advisories serve local consumers: an assessment of mercury in economically important North Carolina fish}, volume={14}, ISSN={["1464-0325"]}, DOI={10.1039/c2em30024a}, abstractNote={Consumption of marine fish provides both benefits (lean protein, omega-3 fatty acids and essential nutrients) and risks (main source of mercury (Hg) exposure for humans). Mercury is a potent neurotoxin and the source of more fish advisories nationwide than any other toxicant. Despite the widespread nature of Hg, it is unknown whether local Hg contamination reflects national and regional levels often used as bases to inform consumers of potential fish consumption risk. Thus, the objectives of our study were to examine Hg levels of six commonly consumed marine species harvested locally off the North Carolina coast and to compare our results to published regional (Monterey Bay Aquarium's Seafood Watch List) and national (Environmental Protection Agency, EPA, and Food and Drug Administration, FDA) Hg averages, action levels, and guidelines. We found significant differences in Hg concentrations among collected species, and we identified correlations between Hg concentration and fish length and trophic levels. Collected mahi mahi and triggerfish were below the EPA fish tissue action level (0.3ppm). Wahoo and grouper exceeded the EPA action level but were below the FDA action level (1.0ppm). King mackerel had the highest Hg concentration among targeted species, exceeding both EPA and FDA action levels. Further, our local results were not always consistent with calculated averages from EPA and FDA databases for the same species, and although many of our findings were consistent with Monterey Bay Aquarium's Seafood Watch List (southeast region), recommendations based on Hg levels would conflict with recommendations they provide based on sustainability. We find regional and national averages are not always reflective of local Hg contamination and suggest local data may be needed to accurately assess consumer risk.}, number={5}, journal={JOURNAL OF ENVIRONMENTAL MONITORING}, author={Petre, Sally Jane and Sackett, Dana K. and Aday, D. Derek}, year={2012}, month={May}, pages={1410–1416} }
 @article{may_aday_hale_denlinger_marschall_2012, title={Modeling Habitat Selection of a Top Predator: Considering Growth and Physical Environments in a Spatial Context}, volume={141}, ISSN={["1548-8659"]}, DOI={10.1080/00028487.2012.655122}, abstractNote={AbstractMechanisms associated with habitat selection by fishes are often unknown and require both physical habitat and growth environment considerations. We used spatially explicit prey biomass estimates, predator growth rate potential (GRP), bottom slope, predator distance from shore, and substrate data to predict habitat use of the saugeye (walleye Sander vitreus × sauger S. canadensis), a popular sport fish that is stocked throughout the central United States. We used telemetry to determine saugeye locations, acoustics to estimate prey biomass and distributions, and a bioenergetics model to aid in calculation of GRP. Akaike's information criterion was used to determine which habitat variables were most important in explaining saugeye location. Models that included both physical habitat and either GRP or prey density performed better than models that considered only one of these parameter types. The resulting models provided the data to create location suitability maps. In general, saugeyes favored steep slopes over hard substrates in nearshore areas with high biomass of gizzard shad Dorosoma cepedianum or high GRP. This comprehensive analysis suggests that the consideration of both spatial habitat suitability and temporal prey availability may improve fisheries management and conservation through a quantitative appreciation of available resources.}, number={1}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={May, Cassandra J. and Aday, D. Derek and Hale, R. Scott and Denlinger, Jonathan C. S. and Marschall, Elizabeth A.}, year={2012}, month={Jan}, pages={215–223} }
 @article{feiner_aday_rice_2012, title={Phenotypic shifts in white perch life history strategy across stages of invasion}, volume={14}, ISSN={["1573-1464"]}, DOI={10.1007/s10530-012-0231-z}, number={11}, journal={BIOLOGICAL INVASIONS}, author={Feiner, Zachary S. and Aday, D. Derek and Rice, James A.}, year={2012}, month={Nov}, pages={2315–2329} }
 @article{donaldson_aday_cooke_2011, title={A Call for Mini-Reviews: An Effective but Underutilized Method of Synthesizing Knowledge to Inform and Direct Fisheries Management, Policy, and Research}, volume={36}, ISSN={["0363-2415"]}, DOI={10.1080/03632415.2011.10389084}, abstractNote={AbstractRemaining current on emerging research in fisheries science is challenging. While review articles are often a go‐to resource for managers and researchers alike, reviews in certain fisheries science subdisciplines are either dated or simply do not exist. Although there are a number of journals that publish lengthy reviews on topics relevant to fisheries, these are not always accessible and may not be read by managers, policymakers, and legislators. To address these concerns, there is a need for direct, concise, and timely review articles that tackle emerging issues (i.e., mini‐reviews). Reviews of this type are rarely published in American Fisheries Society journals or fisheries journals in general, despite the fact that they have been widely successful and influential (in terms of both academic measures of research “impact” and in affecting change in management and policy) in ecological and conservation journals. We provide suggestions for developing high‐quality mini‐reviews and propose that Fisheries is an ideal outlet for these short and timely articles aimed at reaching a broad, multidisciplinary audience, including scientists, managers, policymakers, legislators, and other stakeholders.}, number={3}, journal={FISHERIES}, author={Donaldson, M. R. and Aday, D. D. and Cooke, S. J.}, year={2011}, month={Mar}, pages={123–129} }
 @article{money_sackett_aday_serre_2011, title={Using River Distance and Existing Hydrography Data Can Improve the Geostatistical Estimation of Fish Tissue Mercury at Unsampled Locations}, volume={45}, ISSN={["1520-5851"]}, DOI={10.1021/es2003827}, abstractNote={Mercury in fish tissue is a major human health concern. Consumption of mercury-contaminated fish poses risks to the general population, including potentially serious developmental defects and neurological damage in young children. Therefore, it is important to accurately identify areas that have the potential for high levels of bioaccumulated mercury. However, due to time and resource constraints, it is difficult to adequately assess fish tissue mercury on a basin wide scale. We hypothesized that, given the nature of fish movement along streams, an analytical approach that takes into account distance traveled along these streams would improve the estimation accuracy for fish tissue mercury in unsampled streams. Therefore, we used a river-based Bayesian Maximum Entropy framework (river-BME) for modern space/time geostatistics to estimate fish tissue mercury at unsampled locations in the Cape Fear and Lumber Basins in eastern North Carolina. We also compared the space/time geostatistical estimation using river-BME to the more traditional Euclidean-based BME approach, with and without the inclusion of a secondary variable. Results showed that this river-based approach reduced the estimation error of fish tissue mercury by more than 13% and that the median estimate of fish tissue mercury exceeded the EPA action level of 0.3 ppm in more than 90% of river miles for the study domain.}, number={18}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, publisher={American Chemical Society (ACS)}, author={Money, Eric S. and Sackett, Dana K. and Aday, D. Derek and Serre, Marc L.}, year={2011}, month={Sep}, pages={7746–7753} }
 @article{midway_aday_kwak_gross_2010, title={Cover Preference of the Carolina Madtom (Noturus furiosus), an Imperiled, Endemic Southeastern Stream Fish}, volume={25}, ISSN={0270-5060 2156-6941}, url={http://dx.doi.org/10.1080/02705060.2010.9664368}, DOI={10.1080/02705060.2010.9664368}, abstractNote={ABSTRACT In a laboratory setting, we investigated cover preference of the Carolina madtom (Noturus furiosus), an imperiled, endemic southeastern USA stream fish. Fish were tested individually and given 24 hours to make a selection from four cover options, including rock, leaf pack, mussel shell, and an artificial cover unit. Among 30 trials, Carolina madtom preferred the artificial cover unit, selecting it 63% of the time. Rock was selected 23% of the time, and leaf pack 13%. Mussel shells were not selected during any trial.}, number={1}, journal={Journal of Freshwater Ecology}, publisher={Informa UK Limited}, author={Midway, S. R. and Aday, D. D. and Kwak, T. J. and Gross, K.}, year={2010}, month={Mar}, pages={151–154} }
 @article{sackett_aday_rice_cope_buchwalter_2010, title={Does proximity to coal-fired power plants influence fish tissue mercury?}, volume={19}, ISSN={["1573-3017"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-79952278475&partnerID=MN8TOARS}, DOI={10.1007/s10646-010-0545-5}, abstractNote={Much of the mercury contamination in aquatic biota originates from coal-fired power plants, point sources that release mercury into the atmosphere. Understanding mercury dynamics is primarily important because of the toxic threat mercury poses to wildlife and humans through the consumption of contaminated fish. In this study, we quantified the relative importance of proximity to coal-fired power plants on mercury accumulation in two fish species of different trophic positions. Fish, water and sediment were collected and analyzed from 14 lakes, seven near to (<10 km) and seven far from (>30 km) coal-fired power plants. Lower tissue mercury and higher tissue selenium concentrations were measured in fish collected near power plants. Moreover, mercury accumulation in fish was driven by biotic characteristics (e.g., trophic position, total length, age), waterbody characteristics (e.g., pH, dissolved organic carbon and sulfate) and distance from power plants. Proximity to an atmospheric point-source of mercury and selenium, such as a coal-fired power plant, affects the quantities of mercury and selenium accumulated in fish tissue. Differences in accumulation are hypothesized to be driven in part by selenium-mitigated reductions in fish tissue mercury near power plants. Although reduced fish tissue mercury in systems near power plants may decrease mercury-specific risks to human consumers, these benefits are highly localized and the relatively high selenium associated with these tissues may compromise ecological health.}, number={8}, journal={ECOTOXICOLOGY}, author={Sackett, Dana K. and Aday, D. Derek and Rice, James A. and Cope, W. Gregory and Buchwalter, David}, year={2010}, month={Nov}, pages={1601–1611} }
 @article{sackett_aday_rice_cope_2009, title={A Statewide Assessment of Mercury Dynamics in North Carolina Water Bodies and Fish}, volume={138}, ISSN={["0002-8487"]}, DOI={10.1577/t08-178.1}, abstractNote={AbstractMercury contamination of aquatic systems has received much attention recently because of potential health effects on humans and wildlife. Although the factors affecting mercury deposition, its conversion to biologically active methylmercury, and its bioaccumulation in aquatic systems have been identified, equivocal results for particular species and systems have hampered policy making. Our study addresses this problem through a comprehensive, statewide synthesis of the available data on fish mercury contamination in North Carolina and the environmental factors associated with methylmercury formation and transport through aquatic food webs. Using data collected by the North Carolina Department of Environment and Natural Resources, the U.S. Environmental Protection Agency, and others, we examined the relationships between a suite of biotic and abiotic factors and tissue mercury concentrations in fish from North Carolina water bodies. Multivariate tests were conducted to create predictive models relating environmental variables to mercury levels in fish, and Akaike's information criterion was used to examine the relative strengths of the candidate models. The best model in our analyses (R2 = 0.81) included species, fish trophic status, ecoregion, and pH. Other important drivers of mercury accumulation were land use patterns (the percentage of the subbasin that is agricultural) and site type (swamps versus lakes, rivers, and bays). Although previous investigations have indicated similar individual relationships, our study is unique in that we examined the relative importance of a large number of biotic and abiotic variables across a range of environments, ecosystems, and species. The results of these analyses should help policymakers in making risk assessment decisions and serve as a template for future investigations.}, number={6}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Sackett, Dana K. and Aday, D. Derek and Rice, James A. and Cope, W. Gregory}, year={2009}, month={Nov}, pages={1328–1341} }
 @article{godbout_aday_rice_bangs_quattro_2009, title={Morphological Models for Identifying Largemouth Bass, Spotted Bass, and Largemouth Bass X Spotted Bass Hybrids}, volume={29}, ISSN={["1548-8675"]}, DOI={10.1577/M08-253.1}, abstractNote={AbstractHybridization is common among many closely related fishes, such as the largemouth bass Micropterus salmoides and spotted bass M. punctulatus. Although these species are common members of the sport fish community in midwestern and southeastern U.S. reservoirs, fairly little is known about their ecological interactions or the potential for the introduction of one species to influence the other species. To address these ecological questions and develop appropriate management strategies, reliable field and laboratory identification of each parental species and their hybrid is required. To that end, we collected juvenile (n = 60) and adult (n = 78) largemouth bass, spotted bass, and largemouth bass × spotted bass hybrids from Lake Norman, North Carolina, a system with a historically strong largemouth bass fishery that recently experienced a spotted bass introduction. We recorded a suite of morphological traits on each individual and correlated those observations with DNA sequences from one mitochondrial marker and three nuclear DNA markers in an attempt to develop morphological field and laboratory methods for identifying individuals of the parental species and their hybrid. After confirming that largemouth bass and spotted bass were hybridizing in Lake Norman, we used classification tree analyses to form dichotomous keys for field and laboratory identification of parental individuals and hybrids at juvenile (50–100 mm total length) and adult (300–500 mm) life stages. These keys should provide fishery biologists and managers with a tool to identify these two species, which commonly interact and closely resemble one another. In addition, these keys should be useful in providing evidence that largemouth bass and spotted bass are hybridizing before more expensive techniques like DNA sequencing are pursued.}, number={5}, journal={NORTH AMERICAN JOURNAL OF FISHERIES MANAGEMENT}, author={Godbout, Jason D. and Aday, D. Derek and Rice, James A. and Bangs, Max R. and Quattro, Joseph M.}, year={2009}, month={Oct}, pages={1425–1437} }
 @article{aday_2007, title={The presence of an invasive macrophyte (Phragmites australis) does not influence juvenile fish habitat use in a freshwater estuary}, volume={22}, ISSN={["0270-5060"]}, DOI={10.1080/02705060.2007.9664185}, abstractNote={ABSTRACT I evaluated the short-term influence of the presence of the invasive macrophyte Phragmites australis on fish use in Old Woman Creek, a freshwater estuary connected intermittently to Lake Erie in northcentral Ohio. With minnow traps, trap nets, and light traps I sampled juvenile fish in two areas of the estuary, one dominated by P. australis and the other dominated by a native macrophyte, narrow-leaved cattail (Typha angustifolia). The number of fish species present and the total number of individuals were similar in each habitat, indicating that habitat use by fish was not influenced by the presence of P. australis.}, number={3}, journal={JOURNAL OF FRESHWATER ECOLOGY}, author={Aday, Derek}, year={2007}, month={Sep}, pages={535–537} }
 @article{aday_shoup_neviackas_kline_wahl_2005, title={Prey community responses to bluegill and gizzard shad foraging: Implications for growth of juvenile largemouth bass}, volume={134}, ISSN={["1548-8659"]}, DOI={10.1577/T04-073.1}, abstractNote={AbstractBluegill Lepomis macrochirus, gizzard shad Dorosoma cepedianum, and largemouth bass Micropterus salmoides are common lentic species that may compete for invertebrate prey resources, and interactions among these species can have important consequences for aquatic community structure. Differential foraging behavior of bluegills and gizzard shad as juveniles, for example, may structure zooplankton and benthos communities and influence the growth of juvenile largemouth bass. We conducted a mesocosm experiment (1.6‐m‐diameter circular tanks) in which we allowed high and low densities of juvenile bluegills (70–100 mm total length [TL]) and gizzard shad (135–155 mm TL) to forage on established zooplankton and benthos communities for 6 weeks. After this period, we added juvenile largemouth bass (50–80 mm TL) to each tank for 4 weeks to examine growth and diets. Although foraging by bluegill and gizzard shad had limited effects on the total population densities of invertebrates, important taxon‐specific effects were observed. At the time that largemouth bass were added to tanks, bluegill treatments exhibited a higher macrozooplankton density, higher turbidity, and lower density of larval hydrophilid coleopterans than did gizzard shad or control treatments. The growth of juvenile largemouth bass was strongly influenced by treatment; largemouth bass grew at similar rates in the gizzard shad and control treatments but lost weight in the bluegill treatments. We suggest that bluegills compete with juvenile largemouth bass for preferred prey items, thereby limiting largemouth bass growth. Further, our results demonstrate that the presence of larger gizzard shad may not have the negative implications observed in previous studies with smaller individuals. Knowledge of the relative, size‐specific abundances of bluegills and gizzard shad should provide resource managers with valuable information for developing initiatives aimed at maximizing the growth of juvenile largemouth bass.}, number={5}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Aday, DD and Shoup, DE and Neviackas, JA and Kline, JL and Wahl, DH}, year={2005}, month={Sep}, pages={1091–1102} }
 @article{aday_philipp_wahl_2006, title={Sex-specific life history patterns in bluegill (Lepomis macrochirus): interacting mechanisms influence individual body size}, volume={147}, ISSN={["1432-1939"]}, DOI={10.1007/s00442-005-0242-x}, abstractNote={The ultimate body size that an individual fish achieves can be a function both of direct effects of growth or indirect effects associated with the timing of sexual maturation (and associated energetic tradeoffs). These alternatives are often invoked to explain variation in body size within and among fish populations, but have rarely been considered simultaneously. We assessed how resource availability and timing of maturation interact to influence individual body size of bluegill (Lepomis macrochirus). Resource availability (high and low food) and the social structure of the population (presence or absence of large, mature males) were varied in experimental ponds. Food ration affected growth (larger fish in the high food treatments) and the social structure of the population affected timing of maturation (early maturation of males in the absence of large males). Treatment effects, however, were sex-specific; males responded to the social structure of the population and females were more responsive to resource availability. We also found individuals that became sexually mature were smaller than those that remained immature, although results were sex-specific and resource dependent. For males, individuals that matured were smaller when resources were limited; mature and immature females showed no difference in body size regardless of food ration. We show that both resource availability and the processes that control timing of maturation interact in sex-specific ways to influence body size of bluegill. These results suggest that a more robust explanation for variable body size requires consideration of sex-specific interactions between ecological (food and growth) and evolutionary (timing of maturation) mechanisms.}, number={1}, journal={OECOLOGIA}, author={Aday, DD and Philipp, DP and Wahl, DH}, year={2006}, month={Feb}, pages={31–38} }
 @article{berra_aday_2004, title={Otolith description and age-and-growth of nursuryfish, Kurtus gulliveri, from Northern Australia}, volume={65}, DOI={10.1111/j.1095-8649.2004.00454.x}, journal={Journal of Fish Biology}, author={Berra, T. M. and Aday, D. D.}, year={2004}, pages={354–362} }
 @article{aday_wahl_philipp_2003, title={A mechanism for social inhibition of sexual maturation in bluegill}, volume={62}, ISSN={["1095-8649"]}, DOI={10.1046/j.1095-8649.2003.00033.x}, abstractNote={Social control of maturation is a common phenomenon in fishes, yet associated mechanisms are often unidentified. An examination of interactions between mature and juvenile male bluegill Lepomis macrochirus in mesocosms, isolating visual, chemical and physical interactions, suggested that chemical cues are responsible for inhibiting maturation of juvenile males.}, number={2}, journal={JOURNAL OF FISH BIOLOGY}, author={Aday, DD and Wahl, DH and Philipp, DP}, year={2003}, month={Feb}, pages={486–490} }
 @article{aday_wahl_philipp_2003, title={Assessing population-specific and environmental influences on bluegill life-histories: a common garden approach}, volume={84}, DOI={10.1890/02-3139}, abstractNote={Investigations into vertebrate life histories have demonstrated trade-offs between growth and reproduction that can result in individual and population-specific variation in life-history strategies. Mechanisms to explain variation among populations, however, often remain unidentified. We examined the relative strength of genetic (population source) and environmental (population social structure) factors on variation in growth and timing of maturation for juvenile male bluegill in a common garden experiment. We placed juvenile male bluegill collected from two different wild source populations, one with parental males that are large (>190 mm total length) and one with parental males that are stunted (<155 mm total length), in a common environment and varied the social structure by controlling the presence or absence of large, mature, male bluegill collected from a third population. Juvenile male bluegill from both populations allocated significantly more energy to reproduction in the absence of large males than in their presence. Within ponds, differences in growth and maturation rates between juvenile males from the two source populations were small but significant. These results indicate both genetic and environmental components to growth and maturation in bluegill but emphasize the importance of social interactions in shaping individual life-history strategies.}, journal={Ecology (Brooklyn, New York, N.Y.)}, author={Aday, D. D. and Wahl, D. H. and Philipp, D. P.}, year={2003}, pages={3370–3375} }
 @article{aday_hoxmeier_wahl_2003, title={Direct and indirect effects of gizzard shad on bluegill growth and population size structure}, volume={132}, ISSN={["0002-8487"]}, DOI={10.1577/1548-8659(2003)132<0047:DAIEOG>2.0.CO;2}, abstractNote={Abstract Competition with gizzard shad Dorosoma cepedianum has been shown to influence survival of larval bluegills Lepomis macrochirus as well as growth and size structure of largemouth bass Micropterus salmoides, which prey on these planktivorous species. However, little is known about how the presence of gizzard shad influences bluegills beyond the larval stage. We examined bluegill–gizzard shad interactions across 10 reservoirs with and 10 without gizzard shad to determine direct and indirect effects of gizzard shad on bluegill population size structure. In the presence of gizzard shad, bluegills exhibited smaller adult (>3 years old) size structure. Benthic invertebrate densities were higher in non-gizzard shad reservoirs, which may have contributed to increased bluegill growth in these systems. In contrast, zooplankton densities were similar in reservoirs with and without gizzard shad. Turbidity was higher in reservoirs with gizzard shad, which may have reduced foraging success and growth of bluegil...}, number={1}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Aday, DD and Hoxmeier, RJH and Wahl, DH}, year={2003}, month={Jan}, pages={47–56} }
 @article{aday_kush_wahl_philipp_2002, title={The influence of stunted body size on the reproductive ecology of bluegill Lepomis macrochirus}, volume={11}, ISSN={["1600-0633"]}, DOI={10.1034/j.1600-0633.2002.00011.x}, abstractNote={Abstract – Although stunting is a common phenomenon in fish populations, the consequences of stunted body size on the reproductive ecology of individuals has received little attention. The present study compares the reproductive ecology of bluegill in established stunted and non‐stunted populations. Three ponds (two non‐stunted and one stunted) were monitored for spawning activity throughout the summer. Parental male bluegill from both non‐stunted populations were older, larger, and had greater mating success (number of eggs or fry within nests) than parental males in the stunted population. Stunted bluegill also experienced a shortened reproductive season owing to the delay in onset of spawning. The present study demonstrates that individual size and population size structure can have a marked influence on the reproductive ecology of bluegill.}, number={3}, journal={ECOLOGY OF FRESHWATER FISH}, author={Aday, DD and Kush, CM and Wahl, DH and Philipp, DP}, year={2002}, month={Sep}, pages={190–195} }
 @article{aday_rutherford_kelso_2000, title={Field and laboratory determinations of hypoxic effects on RNA-DNA ratios of bluegill}, volume={143}, ISSN={["0003-0031"]}, DOI={10.1674/0003-0031(2000)143[0433:FALDOH]2.0.CO;2}, abstractNote={Abstract We used RNA-DNA ratios in both field and laboratory experiments to examine the effects of hypoxia on short-term growth of bluegill Lepomis macrochirus collected from the lower Atchafalaya River Basin, Louisiana. In the field experiment, RNA-DNA ratios of bluegill (17.8–52.3 g) from hypoxic habitats (DO < 2.0 mg L−1; n = 26) were significantly lower than ratios of bluegill from normoxic habitats (DO > 4.0 mg L−1; n = 31). In each of two laboratory experiments 40 bluegill (14.54–76.70 g) were individually placed in aquaria to test the effects of hypoxia on RNA-DNA ratios. Additionally, bluegill were fed at different rates in the first experiment to determine the effects of feeding level on RNA-DNA ratios. Results of the first experiment confirmed the sensitivity of RNA-DNA ratios to short-term changes in growth, as fed bluegill had significantly higher ratios than starved bluegill. In both experiments RNA-DNA ratios were not significantly different in bluegill subjected to hypoxia. Results of the study indicate that laboratory experiments did not adequately simulate increased bioenergetic demands and fluctuating DO levels found in hypoxic areas of the Basin.}, number={2}, journal={AMERICAN MIDLAND NATURALIST}, author={Aday, DD and Rutherford, DA and Kelso, WE}, year={2000}, month={Apr}, pages={433–442} }