Eric Schultz
University of Connecticut, Ecology & Evolutionary Biology, Faculty Member
Using carbon and nitrogen stable isotope values, we analyzed the trophic position (TP) and the isotopic niche width of lanternfishes from three different fishing grounds in the Southern Pacific Ocean. Fishes from Perú had slightly higher... more
Using carbon and nitrogen stable isotope values, we analyzed the trophic position (TP) and the isotopic niche width of lanternfishes from three different fishing grounds in the Southern Pacific Ocean. Fishes from Perú had slightly higher δ13C values compared with fish from Chilean fisheries grounds. In contrast, δ15N values increased with latitude (North to South). Myctophids TP differed between the three fishing grounds (highest in Central Chile, lowest in Peru). Peruvian fishes had a smaller isotopic niche than the lanternfishes of the Chilean fishing grounds.
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Because human welfare derived from the restoration of aquatic ecological systems can include non-use components, applications of stated preference (SP) valuation such as choice experiments are often required for comprehensive welfare... more
Because human welfare derived from the restoration of aquatic ecological systems can include non-use components, applications of stated preference (SP) valuation such as choice experiments are often required for comprehensive welfare evaluation. Many recent studies apply SP techniques to assess willingness-to-pay (WTP) for policies that affect the ecology of aquatic systems (for example, Bateman et al., 2006; Birol et al., 2008; Boyer and Polasky, 2004; Do and Bennett, 2009; Flores and Shafran, 2006; Hanley et al., 2006; ...
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Stated preference scenarios often describe outcomes to be valued in terms of intermediate biophysical processes or ecosystem services with indirect utility effects, rather than in terms of final, directly welfare‐relevant consequences.... more
Stated preference scenarios often describe outcomes to be valued in terms of intermediate biophysical processes or ecosystem services with indirect utility effects, rather than in terms of final, directly welfare‐relevant consequences. This article evaluates whether valid welfare estimates can emerge from this practice. We begin with a theoretical model demonstrating conditions under which stated preference scenarios that include intermediate outcomes will elicit welfare estimates identical to those from parallel scenarios that include associated final outcomes (i.e., convergent validity will hold). The model demonstrates that a necessary condition for convergent validity is the ability of respondents to correctly predict biophysical production functions linking intermediate to final outcomes. Hypotheses from the theoretical model are then evaluated empirically using an application of choice experiments to migratory fish restoration in the U.S. state of Rhode Island. Empirical results are mixed but generally reject convergent validity; welfare estimates are not robust to the use of an intermediate outcome in lieu of a related final outcome in stated preference scenarios, as predicted by theory. Results of the analysis suggest that greater attention should be given to the reliability of welfare estimation when final outcomes cannot be quantified.
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Background: Post-Pleistocene diversification of threespine stickleback in fresh water offers a valuable opportunity to study how changes in environmental salinity shape physiological evolution in fish. In Alaska, the presence of both... more
Background: Post-Pleistocene diversification of threespine stickleback in fresh water offers a valuable opportunity to study how changes in environmental salinity shape physiological evolution in fish. In Alaska, the presence of both ancestral oceanic populations and derived landlocked populations, including recent lake introductions, allows us to examine rates and direction of evolution of osmoregulation following halohabitat transition. Hypotheses: Strong selection for enhanced freshwater tolerance will improve survival of recently lake-introduced stickleback in ion-poor conditions compared with their oceanic ancestors. Trade-offs between osmoregulation in fresh water and seawater will allow members of the ancestral population to survive better in response to seawater challenge, as mediated by upregulating salt-secreting transporters in the gill. Poorer hypo-osmoregulatory performance of derived fish will be marked by higher levels of taurine and other organic osmolytes. Methods: ...
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River herring—a collective name for the Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis—play a crucial role in freshwater and marine ecosystems along the Eastern Seaboard of North America. River herring are anadromous and... more
River herring—a collective name for the Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis—play a crucial role in freshwater and marine ecosystems along the Eastern Seaboard of North America. River herring are anadromous and return to freshwater habitats in the tens to hundreds of millions to spawn, supplying food to many species and providing nutrients to freshwater ecosystems. After two and a half centuries of habitat loss, habitat degradation, and overfishing, river herring are at historic lows. In 2013, National Oceanic and Atmospheric Administration Fisheries established the Technical Expert Working Group (TEWG) to synthesize information about river herring and to provide recommendations to advance the science related to their restoration. This paper was composed largely by the chairs of the TEWG subgroups and represents a review of the current state of knowledge of river herring, with an emphasis on identification of threats and discussion of recent research and m...
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AbstractInnovative methods for analysis of reproduction may provide more information that can be used to conserve species of concern. We present data on oocyte development, batch size, and batch number of anadromous Alewives Alosa... more
AbstractInnovative methods for analysis of reproduction may provide more information that can be used to conserve species of concern. We present data on oocyte development, batch size, and batch number of anadromous Alewives Alosa pseudoharengus in a lake-spawning population located in Connecticut. We sampled female Alewives as they arrived at the spawning habitat (uprunners) and females as they were leaving (downrunners). We estimated batch size by weighing all oocytes and performed image analysis on oocytes in subsamples of some ovaries, thereby estimating oocyte size-frequency distribution to define the number of batches. We performed both whole-mount and histological analysis on other ovaries to compare gravimetric and stereological estimates of batch size and to precisely characterize oocyte developmental stages. Uprunners had advanced oocytes at the ultimate stage of vitellogenesis and usually three additional less-developed batches. Postovulatory follicles and oocytes that were being resorbed were ...
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1. Experiments were designed to reveal geographic differentiation, and its evolutionary significance, in early life-history characters of Fundulus heteroclitus. The inherited capacity for growth was studied for five populations, from... more
1. Experiments were designed to reveal geographic differentiation, and its evolutionary significance, in early life-history characters of Fundulus heteroclitus. The inherited capacity for growth was studied for five populations, from South Carolina to Maine, USA, at three temperatures representative of field conditions. Two generations of newly hatched fish were reared and tested. The second generation of fish was produced from parents that were themselves reared in the laboratory, in order to control for maternally transmitted ...
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Stated preference analyses often impose strong and unrealistic assumptions regarding the spatial distribution of willingness to pay, including spatial homogeneity and continuous distance decay. Assumptions such as these—increasingly... more
Stated preference analyses often impose strong and unrealistic assumptions regarding the spatial distribution of willingness to pay, including spatial homogeneity and continuous distance decay. Assumptions such as these—increasingly abandoned by non-economics disciplines in favor of approaches that allow for localized patchiness—can have critical implications for benefit transfer. This paper evaluates patchiness and hot spots in stated preference welfare estimates and discusses implications for benefit transfer. The ...
Page 1. Poeciliid Mating Systems, Copulatory Organ Size, and Scaling Relationships By: Martha Divver Dr. Eric Schultz Department of Ecology and Evolutionary Biology Background image of P. petenensis courtesy of Dr. Margaret Ptacek Page 2.... more
Page 1. Poeciliid Mating Systems, Copulatory Organ Size, and Scaling Relationships By: Martha Divver Dr. Eric Schultz Department of Ecology and Evolutionary Biology Background image of P. petenensis courtesy of Dr. Margaret Ptacek Page 2. Overview • Background information • Objectives • Methods • Results • Conclusions Page 3. What are poeciliids? • Live-bearing group of fishes that includes guppies, swordtails, and mollies • Found in local pet stores; popular aquarium fish • Come in a variety of shapes, colors and sizes Page 4. ...
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SUMMARY The alewife (Alosa pseudoharengus) is a clupeid that undergoes larval and juvenile development in freshwater preceding marine habitation. The purpose of this study was to investigate osmoregulatory mechanisms in alewives that... more
SUMMARY The alewife (Alosa pseudoharengus) is a clupeid that undergoes larval and juvenile development in freshwater preceding marine habitation. The purpose of this study was to investigate osmoregulatory mechanisms in alewives that permit homeostasis in different salinities. To this end, we measured physiological, branchial biochemical and cellular responses in juvenile alewives acclimated to freshwater (0.5 p.p.t.) or seawater (35.0 p.p.t.). Plasma chloride concentration was higher in seawater-acclimated than freshwater-acclimated individuals (141 mmol l–1vs 134 mmol l–1), but the hematocrit remained unchanged. In seawater-acclimated individuals, branchial Na+/K+-ATPase (NKA) activity was higher by 75%. Western blot analysis indicated that the abundance of the NKA α-subunit and a Na+/K+/2Cl– cotransporter (NKCC1) were greater in seawater-acclimated individuals by 40% and 200%, respectively. NKA and NKCC1 were localized on the basolateral surface and tubular network of ionocytes i...
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Research Interests: Business, Ecosystem Services, Ecological Economics, Water quality, Valuation (Sustainability), and 15 moreSurvey Methodology, Applied Economics, Aquatic Ecosystem, Ecological Indicator, River Restoration, Choice Model, Ecological Indicators, Choice Experiment, Discrete choice models, Stated Preference, Ecosystem service, Willingness to Pay, Water Quality, ENVIRONMENTAL SCIENCE AND MANAGEMENT, and Index of Biotic Integrity
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Estuaries provide high quality nursery habitat for larval fishes due to high productivity, predator protection, and warm temperatures. Previous studies suggest that larval naked gobies (Gobiosoma bosci) are capable of upriver migration... more
Estuaries provide high quality nursery habitat for larval fishes due to high productivity, predator protection, and warm temperatures. Previous studies suggest that larval naked gobies (Gobiosoma bosci) are capable of upriver migration and estuarine retention despite net seaward flow. Gobiosoma bosci larvae were collected at a fixed site in the Hudson River estuary in late July of 1998 from 4 discrete depths to provide a time-series of depth-stratified abundance during both a spring and a neap tide. Larvae were concentrated at depth, indicating that depth preference behavior is present and will likely contribute to up-river transport. Harmonic regression analysis revealed that larvae are most abundant in samples at night due to periodic diel vertical migrations in which they move deeper than the sampled region during daytime. Dependent upon hydrography of this site, diel vertical movements may also contribute to up-river transport. Larval depth distribution was not homogenized by sp...
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Winter flounder ( Pseudopleuronectes americanus ) come inshore during the late winter and early spring to lay their eggs in shallow bays and estuaries along the coast. Unlike most fish eggs, which are buoyant, these eggs are demersal and... more
Winter flounder ( Pseudopleuronectes americanus ) come inshore during the late winter and early spring to lay their eggs in shallow bays and estuaries along the coast. Unlike most fish eggs, which are buoyant, these eggs are demersal and sink to the seafloor. This makes them vulnerable to burial from various types of natural and human-caused disturbances (e.g., storms, mobile fishing gear, maintenance dredging). Our objective was to map spawning areas in two harbors and search for generalities among these sites that would allow us to predict where winter flounder might spawn in other areas. This would allow managers to avoid permitting activities for those times and locations where winter flounder spawn. We used a modified demersal plankton net (a benthic sled) to collect winter flounder eggs in New Haven and Milford harbors and map their distributions. Most of the eggs were collected at the end of March, when water temperatures were 4-6 ° C. This could vary from year to year depend...
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This Report is brought to you for free and open access by the Department of Ecology and Evolutionary Biology at DigitalCommons@UConn. It hasbeen accepted for inclusion in EEB Articles by an authorized administrator of... more
This Report is brought to you for free and open access by the Department of Ecology and Evolutionary Biology at DigitalCommons@UConn. It hasbeen accepted for inclusion in EEB Articles by an authorized administrator of DigitalCommons@UConn. For more information, please contactdigitalcommons@uconn.edu.
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Page 1. International Association for Ecology Water Relations of Epiphytic and Terrestrially-Rooted Strangler Figs in a Venezuelan Palm Savanna Author(s): N. Michele Holbrook and Francis E. Putz Reviewed work(s): Source: Oecologia, Vol.... more
Page 1. International Association for Ecology Water Relations of Epiphytic and Terrestrially-Rooted Strangler Figs in a Venezuelan Palm Savanna Author(s): N. Michele Holbrook and Francis E. Putz Reviewed work(s): Source: Oecologia, Vol. 106, No. ... Michele Holbrook ? ...
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Some of the authors of this publication are also working on these related projects: IFOP-SUBPESCA 1049/50-LE16: Stomach contents of Micromesistius australis and ratfishes (Coelorhynchus sp) during 2016 View project Eric T Schultz... more
Some of the authors of this publication are also working on these related projects: IFOP-SUBPESCA 1049/50-LE16: Stomach contents of Micromesistius australis and ratfishes (Coelorhynchus sp) during 2016 View project Eric T Schultz University of Connecticut 91 PUBLICATIONS 2,803 CITATIONS SEE PROFILE Stephen D. McCormick USGS, Conte Anadromous Fish Research Center 173 PUBLICATIONS 9,836 CITATIONS SEE PROFILE
Synopsis The cost of reproduction is a central concept in theories of life-history evolution. One way to empirically examine the tradeoff between current reproduction and future reproductive prospects is to use natural intraspecific... more
Synopsis The cost of reproduction is a central concept in theories of life-history evolution. One way to empirically examine the tradeoff between current reproduction and future reproductive prospects is to use natural intraspecific variation in life-history traits. However, this approach is complicated by the sensitivity of life-history traits to variation in the level of resources. We report here an attempt to measure the cost of increasing reproductive activity in populations of female bluehead wrasse, Thalassoma bifasciatum, a coral-reef fish. All of ...
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Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology and physiology influences whole-organism performance will yield... more
Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology and physiology influences whole-organism performance will yield insight into the factors that shape its own evolution. We demonstrate that nonmigratory populations of alewife (Alosa pseudoharengus) have evolved reduced swimming performance in parallel, compared with their migratory ancestor. In contrast to theoretically and empirically based predictions, poor swimming among nonmigratory populations is unrelated to the evolution of osmoregulation and occurs despite the fact that nonmigratory alewives have a more fusiform (torpedo-like) body shape than their ancestor. Our results suggest that elimination of long-distance migration from the life cycle has shaped performance more than changes in body shape and physiological regulatory capacity.
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Comparative approaches in physiological genomics offer an opportunity to understand the functional importance of genes involved in niche exploitation. We used populations of Alewife (Alosa pseudoharengus) to explore the transcriptional... more
Comparative approaches in physiological genomics offer an opportunity to understand the functional importance of genes involved in niche exploitation. We used populations of Alewife (Alosa pseudoharengus) to explore the transcriptional mechanisms that underlie adaptation to fresh water. Ancestrally anadromous Alewives have recently formed multiple, independently derived, landlocked populations, which exhibit reduced tolerance of saltwater and enhanced tolerance of fresh water. Using RNA-seq, we compared transcriptional responses of an anadromous Alewife population to two landlocked populations after acclimation to fresh (0 ppt)- and salt-water (35 ppt). Our results suggest that the gill transcriptome has evolved in primarily discordant ways between independent landlocked populations and their anadromous ancestor. By contrast, evolved shifts in the transcription of a small suite of well-characterized osmoregulatory genes exhibited a strong degree of parallelism. In particular, transc...
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Stated preference scenarios often provide information on intermediate biophysical processes but omit information on the resulting final services that provide utility. This may cause respondents to speculate about the effects of... more
Stated preference scenarios often provide information on intermediate biophysical processes but omit information on the resulting final services that provide utility. This may cause respondents to speculate about the effects of intermediate outcomes on their welfare, leading to biased welfare estimates. This work clarifies distinctions between intermediate and final ecosystem services within stated preference valuation and develops a structural model by which to infer respondents’ speculations when a final ecosystem service is omitted. The model also derives implications for welfare estimates. Methods and results are illustrated using an application of choice experiments to fish restoration in Rhode Island's Pawtuxet watershed.