Progress 06/06/08 to 06/05/14
Outputs
Target Audience: Membership of the American Fisheries Society, via Dr. Neill's participation in a symposium on "Population Productivity Drivers and Spatial Scale: A Case Study with Red Drum," at the 143rd annual meeting of the Society, in Little Rock, AR, September 2013. Membership of the American Fisheries Scociety consists of undergraduate and graduate college students, teachers, scientists, managers, and administrators who are involved in or otherwise concerned with fisheries science, conservation, management and/or policy. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Under auspices of this project and its educational outgrowths, many graduate students and upper-division undergraduates have learned principles of fish biology, and have developed their own research and analytical skills. About 20 graduate students at Texas A&M University and elsewhere did research that contributed directly to development of Ecophys.Fish and EcoFish. In addition, several colleagues have studied and used these models. Two, Drs. Thomas Torgersen of Norway and Vanessa Fonseca of Portugal, traveled from Europe to Texas A&M and spent time-in-residence studying with Dr. Neill. Opportunities for training and professional development have been of particular benefit to colleagues in Texas Parks and Wildlife Department's Coastal Fisheries Division. Several former and current staff, including Dr. Robert Vega, TPWD Director for Marine Stock Enhancement, have been intimately involved with this project, in multiple roles, including those of student, teacher, technician and research collaborator. ...and those opportunities should continue, indefinitely, because complete and interactive archives of Biology of Fishes and its central model EcoFish remain available, via USB flash-drive, for the benefit of future users. How have the results been disseminated to communities of interest? Results have been disseminated to communities of interest, primarily via scholarly publication and papers presented at scientific meetings. These published and presented papers have been reported previously. But, it is important to emphasize that these vehicles serve primarily to establish credibility of project findings. The real impact of those findings, over the longer term, will be to strenghten and facilitate scientific understanding of fisheries science for the students, teachers, and researchers of the future. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Reseach findings (goals 1-3), in summary: Ecophysiological research and simulation modeling, under auspices of this project and in collaboration with colleagues at Texas Parks and Wildlife Department (TPWD), has enabled analysis of juvenile-fish-survey data, in the context of juvenile-fish-stocking data, to assess efficacy of stock enhancement for red drum (Sciaenops ocellatus) in Texas. This analysis indicates that juvenile red drum reared in and released from TPWD hatcheries since 1990 may have added (net gain, accounting for supplanted wild fish) about 10.8 %, or over 4.7 million extra fish, to the fishable stock of this species in Texas waters. Goal 4: The final phase of this project focused on integration and leveraging of research findings for education, via delopment and implementation of the STELLA simulation model "EcoFish." This teaching/communications model extends and enhances the scope of our published research model Ecophys.Fish (Neill et al., Reviews in Fisheries Science 12:233-288, 2004). EcoFish provides students and colleagues an endless supply of virtual subjects for simulated experiments in fish autecology. Stochastic results are consistent with those measured for real fish in our past research.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: This project seeks broad understanding of aquatic-production systems, with emphasis on propagation of environmental effects through the individual organism, to the levels of population and community. In 2012, the process of organizing a final project report continued, together with expanded effort toward development of a more robust environmental context for Ecophys.Fish (E.F), our simulation model of fish growth and production in time-varying environments (Rev. Fish. Sci. 12:233-288, 2004; and, Trans. Amer. Fish. Soc. 136:1193-1205, 2007). The latter activity has focused on using routinely collected temperature, salinity, and dissolved-oxygen data as inputs for a model to simulate pond pH and fish production. These and related efforts involved extensive and highly substantive collaboration with colleagues at Texas Parks and Wildlife Department. PARTICIPANTS: This project involves very effective and mutually beneficial collaboration among P.I. Neill, his Texas A&M University faculty and student colleagues, and Dr. Robert Vega, Director for Marine Stock Enhancement, Coastal Fisheries Division, Texas Parks and Wildlife Department, and Dr. Vega's staff. The collaboration is enhanced by activities such as live seminars enabled by Internet-based communication, and through joint participation by Drs. Neill and Vega in thesis research projects conducted by Texas A&M University-Corpus Christi graduate students at facilities operated by TPWD, and through informal participation by Dr. Vega and his staff at TPWD in Dr. Neill's graduate-level course in fish biology at Texas A&M University (WFSC 617). A unifying theme in these collaborative activities is the development and application of simulation models emerging from Ecophys.Fish. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The elaboration of Ecophys.Fish as Ecophys.Pond represents an unfinished but promising attempt to translate ordinary "water quality" data (temperature, salinity, DO, alkalinity and pH) into rates of fish growth and production in coastal ponds. The target is a practical but mechanism-based tool for better managing aquacultural and fishery systems. Equally important, this effort is resulting in simulation models like "EcoFish," which serve very effectively as "subjects" for virtual experiments being performed in undergraduate and graduate teaching laboratories.
Publications
- Vega, R.R., W.H. Neill, J.R. Gold, M.S. Ray. 2011. Enhancement of Texas Sciaenids (red drum and spotted seatrout). In: R. Stickney, R. Iwamoto, and M. Rust, editors. Interactions of fisheries and fishing communities related to aquaculture: Proceedings of the Thirty-Eighth U.S.-Japan Aquaculture Panel Symposium, Corpus Christi, Texas, October 26-27, 2009. U.S. Dept. Commerce, NOAA Tech. Memo. NMFS-F/SPO-113, p. 85-92.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: This project seeks broad understanding of aquatic-production systems, with emphasis on propagation of environmental effects through the individual organism, to the levels of population and community. In 2011, the process of organizing a final project report began, together with continued effort toward development of a more robust environmental context for Ecophys.Fish (E.F), our simulation model of fish growth and production in time-varying environments (Rev. Fish. Sci. 12:233-288, 2004; and, Trans. Amer. Fish. Soc. 136:1193-1205, 2007). The latter activity has focused on using routinely collected temperature, salinity, and dissolved-oxygen data as inputs for a model to simulate pond pH and fish production. These and related efforts involved extensive and highly substantive collaboration with colleagues at Texas Parks and Wildlife Department. PARTICIPANTS: This project involves very effective and mutually beneficial collaboration among P.I. Neill, his Texas A&M University faculty and student colleagues, and Dr. Robert Vega, Director for Marine Stock Enhancement, Coastal Fisheries Division, Texas Parks and Wildlife Department, and Dr. Vega's staff. The collaboration is enhanced by activities such as live seminars enabled by Internet-based communication, and through joint participation by Drs. Neill and Vega in thesis research projects conducted by Texas A&M University-Corpus Christi graduate students at facilities operated by TPWD. A unifying theme in these collaborative activities is the development and application of simulation models emerging from Ecophys.Fish. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The elaboration of Ecophys.Fish as Ecophys.Pond represents an unfinished but promising attempt to translate ordinary "water quality" data (temperature, salinity, DO, alkalinity and pH) into rates of fish growth and production in coastal ponds. The target is a practical but mechanism-based tool for better managing aquacultural and fishery systems. Equally important, this effort is resulting in simulation models like "EcoFish," which serve very effectively as "subjects" for virtual experiments being performed in undergraduate and graduate teaching laboratories.
Publications
- WALKER, S.J., NEILL, W.H., LAWRENCE, A.L., and GATLIN, D.M. III. 2011. Effects of temperature and starvation on ecophysiological performance of the Pacific white shrimp (Litopenaeus vannamei). Aquaculture 319:439-445.
- BUENTELLO, J.A., POHLENZ, C., MARGULIES, D., SCHOLEY, V.P., WEXLER, J.B., TOVAR-RAMIREZ, D., NEILL, W.H., HINOJOSA-BALTAZAR, P., and GATLIN, D.M. III. 2011. A preliminary study of digestive enzyme activities and amino acid composition of early juvenile yellowfin tuna (Thunnus albacares). Aquaculture 312:205-211.
- STRONGIN, K., TAYLOR, C.M., ROBERTS, M.E., NEILL, W.H., and GELWICK, F. 2011. Food habits and dietary overlap of two silversides in the Tennessee-Tombigbee Waterway: The invasive Menidia audens versus the native Labidesthes sicculus. Am. Midl. Nat. 166:224-233.
- GAUTAM, R., BANI-YAGHOUB, M., NEILL, W.H., DOPFER, D., KASPAR, C., and IVANEK, R. 2011. Modeling the effect of seasonal variation in ambient temperature on the transmission dynamics of a pathogen with a free-living stage: Example of Escherichia coli O157:H7 in a dairy herd. Prevent. Vet. Med. 102:10-21.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: This project seeks broad understanding of aquatic-production systems, with emphasis on propagation of environmental effects through the individual organism, to the levels of population and community. Activity in 2010 focused on providing a more robust environmental context for Ecophys.Fish (E.F), our simulation model of fish growth and production in time-varying environments (Rev. Fish. Sci. 12:233-288, 2004; and, Trans. Amer. Fish. Soc. 136:1193-1205, 2007). Physical-chemical data from coastal ponds, together with textbook calculations of chemical dynamics, were used to model pond oxygen and carbon cycles, resulting in simulation of diel and seasonal trends in dissolved oxygen concentration (DO), pH, and carbon fixation leading to production of forage eaten by cultured fish. These and related efforts involved extensive and highly substantive collaboration with colleagues at Texas Parks and Wildlife Department, and provided opportunities for training 2 M.S. students and 2 Ph.D. students. PARTICIPANTS: This project involves very effective and mutually beneficial collaboration among P.I. Neill, his Texas A&M University faculty and student colleagues, and Dr. Robert Vega, Director for Marine Stock Enhancement, Coastal Fisheries Division, Texas Parks and Wildlife Department, and Dr. Vega's staff. The collaboration is enhanced by activities such as live seminars enabled by Internet-based communication, and through joint participation by Drs. Neill and Vega in thesis research projects conducted by Texas A&M University-Corpus Christi graduate students at facilities operated by TPWD. A unifying theme in these collaborative activities is the development and application of simulation models emerging from Ecophys.Fish. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The elaboration of Ecophys.Fish as Ecophys.Pond represents an unfinished but promising attempt to translate ordinary "water quality" data (temperature, salinity, DO, alkalinity and pH) into rates of fish growth and production in coastal ponds. The target is a practical but mechanism-based tool for better managing aquacultural and fishery systems. Equally important, this effort is resulting in simulation models like "EcoFish," which serve very effectively as "subjects" for virtual experiments being performed in undergraduate and graduate teaching laboratories.
Publications
- WALKER, S.J., NEILL, W.H., LAWRENCE, A.L., and GATLIN, D.M. III. 2009. Effect of salinity and body weight on ecophysiological performance of the Pacific white shrimp (Litopenaeus vannamei). J. Exp. Mar. Biol. Ecol. 380:119-124.
- FONSECA, V.F., NEILL, W.H., MILLER, J.M., and CABRAL, H.N. 2010. Ecophys.Fish perspectives on growth of juvenile soles, Solea solea and Solea senegalensis, in the Tagus estuary, Portugal. J. Sea Research 64:118-124.
- VEGA, R.R., NEILL, W.H., GOLD, J.R., and RAY, M.S. 2011. Enhancement of Texas sciaenids (red drum and spotted seatrout). Proc. UJNR 2010 Symposium. In press.
- BUENTELLO, J.A., POHLENZ, C., MARGULIES, D., SCHOLEY, V.P., WEXLER, J.B., TOVAR-RAMIREZ, D., NEILL, W.H., HINOJOSA-BALTAZAR, P., and GATLIN, D.M. III. 2011. A preliminary study of digestive enzyme activities and amino acid composition of early juvenile yellowfin tuna (Thunnus albacares). Aquaculture. In press.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: This project seeks broad understanding of aquatic-production systems, with emphasis on propagation of environmental effects through the individual organism, to the levels of population and community. Activity in 2009 focused on generalization of Ecophys.Fish (E.F), our simulation model of fish growth in time-varying environments (Rev. Fish. Sci. 12:233-288, 2004), to new species. Model variants were developed and parameterized for Pacific white shrimp (Litopenaeus vannamei), and for two flatfish species, the northern sole (Solea solea) and the Senagalese sole (Solea senegalensis). In addition, we continued work to enhance the generic E.F model for accommodation of ecophysiological feedbacks from intensively cultured aquatic organisms, to ecological dynamics of the production system itself. These and related efforts involved extensive and highly substantive collaboration with colleagues at Texas Parks and Wildlife Department, and provided opportunities for training 3 M.S. students and 2 Ph.D. students. PARTICIPANTS: This project involves very effective and mutually beneficial collaboration between P.I. Neill, his Texas A&M University faculty and student colleagues, and Dr. Robert Vega, Director for Marine Stock Enhancement, Coastal Fisheries Division, Texas Parks and Wildlife Department, and Dr. Vega's staff. The collaboration is enhanced by activities such as live seminars enabled by Internet-based communication. For example, during fall 2009, in a weekly seminar on issues at the interfaces of aquaculture and fisheries, we used a combination of Centra, Camtasia, and Skype to engage our Texas A&M group on campus in College Station; distant graduate students in San Antonio and in Miami, FL; and, Dr. Vega and his staff, both at the CCA/AEL Marine Development Center in Corpus Christi and at Sea Center Texas, in Lake Jackson. During the course of the semester, we had seminars originating at 4 of the 5 locations (all except Lake Jackson). TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The shrimp variant of the E.F model incorporated a sub-model to accommodate molting and to resolve effects of metabolic shifts concurrent with the out-migration of juvenile shrimp from estuarine to oceanic waters. The flatfish variant was able to account ecophysiologically for differences in distribution and interannual performance of the two sole species. The work on feedback of animal biology to system ecology led to development of a mechanistic model for simulating aspects of water chemistry--dissolved O2, CO2, pH, and alkalinity--in coastal ponds used for aquacultural production. All these efforts are resulting not only in practical tools for better managing aquacultural and fishery systems, but also in technical publications in peer-reviewed journals. Equally important, they are resulting in simulation models like "EcoFish," which serve very effectively as "subjects" for virtual experiments being performed in undergraduate and graduate teaching laboratories. A 16-min audio-image "tour" of EcoFish (and the associated fish biology course) is available at http://wfscdisted.tamu.edu/Neill/EcoFishPresShort600x800.html.
Publications
- WALKER, S.J. 2009. Ecophysiology of growth in the Pacific white shrimp (Litopenaeus vannamei). Ph.D. Dissertation, Texas A&M University, College Station, TX. 114 p.
- STRONGIN, K.R. 2009. Silverside diets and potential competition in the Tennessee-Tombigbee Waterway: The invasive Menidia audens versus the native Labidesthes sicculus. M.S. Thesis, Texas A&M University, College Station, TX. 24 p.
- BURR, G., HUME, M., NEILL, W.H., and GATLIN III, D.M. 2008. Effects of prebiotics on nutrient digestibility of a soybean-meal-based diet by red drum Sciaenops ocellatus (Linnaeus). Aquaculture Research 39:1680-1686.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: This project seeks broad understanding of aquatic-production systems, with emphasis on propagation of environmental effects through the individual organism, to the levels of population and community. Activity in 2008 focused on further evaluation and development of Ecophys.Fish, our simulation model of fish growth in time-varying environments (Rev. Fish. Sci. 12:233-288, 2004), now augmented with a submodel of natural mortality. We used the enhanced model to project performance of juvenile red drum over the first year of a two-year study in ponds at the Marine Development Center (MDC) in Corpus Christi, TX, and Sea Center Texas (SCT) in Lake Jackson, TX. The model suggested that survival and growth were limited by feed insufficiency and that competition for limited feed may have caused the high degree of observed growth dispersion. Results are being used to optimize future feeding regimes for the fingerling-production ponds both at MDC and SCT. Other project activities focused on development of holistic measures of goodness-of-fit for comparing performance of alternative simulation models that generate multiple ecophysiological outputs. PARTICIPANTS: Key project collaborators included Dr. Robert Vega, Texas Parks and Wildlife Department; Drs. Del Gatlin, Mike Speed, Wally Wu, and John Gold, all at Texas A&M University (TAMU); and, Dr. Thomas Torgersen, Norwegian Institute of Marine Research. Ph.D. students Lance Fontaine (TAMU), Scott Walker (TAMU), and Vanessa Fonseca (Univ. Portugal) also were important contributers to the project. TARGET AUDIENCES: Fishery and aquacultural scientists engaged in research and teaching, especially re fish autecology and production. Fishery managers and aquacultural producers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Project results are being incorporated both into the simulation model "EcoFish," used in teaching at Texas A&M University, and also into management of marine stock enhancement by Texas Parks and Wildlife Department.
Publications
- FONTAINE, L.P. 2008. Interaction of temperature, dissolved oxygen and feed energy on ecophysiological performance of juvenile red drum. Ph.D. Dissertation, Texas A&M University, College Station, TX. 161 p.
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Progress 01/01/07 to 12/31/07
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual fish, to the levels of population and community. Activity in 2007 focused on further evaluation and development of Ecophys.Fish (E.F), our simulation model of fish growth in time-varying environments (Rev. Fish. Sci. 12:233-288, 2004). We published an important paper (Trans. Amer. Fish. Soc. 136:1193-1205), reporting experimental support for a key hypothesis emerging from E.F: Growth of fish exposed to high temperatures tends to be limited by available food energy; whereas, at lower temperatures, the limit tends to be set by metabolic scope that is insufficient for exploiting available food energy. Research activities included extending E.F to better accommodate issues of fish health and welfare, and experiments to generalize E.F for application to marine shrimp. E.F with a size-dependent natural-mortality function was applied
to refine interpretation of recapture rates for released juvenile red drum identified via natural genetic markers. Impacts of this project include improved techniques for aquaculture and for managing wild fish stocks
Impacts
Nothing at this time
Publications
- Fontaine, L.P., Whiteman, K.W., Li, P., Burr, G.S., Webb, K.A., Goff, J., Gatlin, D.M. III, Neill, W.H., Davis, K.B., and Vega, R.R. 2007. Effects of temperature and feed energy on the performance of juvenile red drum. Transactions of the American Fisheries Society 136:1193-1205.
- Li, P., Gatlin III, D.M., and Neill, W.H. 2007. Dietary supplementation of a purified nucleotide mixture transiently enhanced growth and feed utilization of juvenile red drum Sciaenops ocellatus. Journal of the World Aquaculture Society 38:281-286.
- Ma, L., Saillant, E., Gatlin, D.M. III, Neill, W.H., Vega, R.R., and Gold, J.R. 2007. Heritability of cold tolerance in red drum. North American Journal of Aquaculture 69: 381-387.
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Progress 01/01/06 to 12/31/06
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual fish, to the levels of population and community; particular attention is directed to feed back loops between fish and environment. Activity in 2006 focused on development of an ecophysiology based approach for interpreting temporal and spatial fluctuations in numbers of juvenile red drum in Texas coastal waters. We added a size dependent natural mortality function to our simulation model of fish growth in time varying environments (Rev. Fish. Sci. 12:233-288, 2004) and used that to analyze Texas Parks and Wildlife Department's 30 year long seine sampling database. Preliminary results suggest that the integrated model can account for up to 60 percent of the variance in red drum sport fishery catches since 1977; and, that stock enhancement is responsible for about 18 percent of that yield since 1990. Impacts of this project
include improved strategies for managing marine fish stock enhancement practices and strategies.
Impacts
Impact statement was not submitted for this year.
Publications
- CORNICK, L.A., NEILL, W.H., and GRANT, W.E. 2006. Assessing competition between Steller sea lions and the commercial groundfishery in Alaska: A bioenergetics modelling approach. Ecological Modelling 199:107-114.
- LI, P., GATLIN III, D.M., and NEILL, W.H. 2007. Dietary supplementation of a purified nucleotide mixture transiently enhanced growth and feed utilization of juvenile red drum Sciaenops ocellatus. Journal of the World Aquaculture Society.
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Progress 01/01/05 to 12/31/05
Outputs
This project seeks broad understanding of fish production systems, with emphasis on propagation of environmental effects through the individual fish, to the levels of population and community; particular attention is directed to feed back loops between fish and environment. Activity in 2005 focused on laboratory and pond experiments to evaluate hypotheses emerging from Ecophys.Fish, our simulation model of fish growth in time varying environments (Rev. Fish. Sci 12:233-288, 2004). Both in tank and pond experiments, and as predicted, low energy feeds tended to limit growth of juvenile red drum (Sciaenops ocellatus), even when such feeds were provided in excess of demand. The limitation was exacerbated by elevated temperature. Feed supplements such as brewers yeast and nucleotides provided no apparent relief. Mortality rates for fish in the pond experiments (4 %/day at 0.5 g, down to 0.6 %/day at 4 g) were similar to those that have been estimated for red drum of
similar size in the wild despite lack of fish predators (other than cannibalistic red drum) in the ponds. Impacts of this project include improved strategies for managing red drum in ponds for stock enhancement and for food fish production.
Impacts
Model of fish performance is being used as a tool for planning marine fish stock enhancement in Texas.
Publications
- LI, P., BURR, G.S., GOFF, J., WHITEMAN, K.W., DAVIS, K.B., VEGA, R.R., NEILL, W.H., and GATLIN III, D.M. 2005. A preliminary study on the effects of dietary supplementation of brewers yeast and nucleotides, singularly or in combination, on juvenile red drum (Sciaenops ocellatus). Aquaculture Research 36: 1120-1127.
- CORNICK, L.A., NEILL, W.H., and GRANT, W.E. 2005. In press. Assessing competition between Steller sea lions and the commercial groundfish harvest in Alaska: A bioenergetics modeling approach. Ecological Modelling.
- BHUTHIMETHEE, M., DRONEN JR., N.O., and NEILL, W.H. 2005. In Press. Metazoan parasite communities of sentinel bluegill caged in two urbanizing streams, San Antonio, Texas. Journal of Parasitology.
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Progress 01/01/04 to 12/31/04
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual fish, to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Activity in 2004 focused on publication of a major paper (Neill et al. 2004) that integrated findings from the past several years of ecophysiological research, in the form of a simulation model of fish growth. Hypotheses that have emerged from this model are being tested in the current phase of our research, funded by Sea Grant. One key hypothesis already finding support in controlled laboratory experiments, is this: Feed energy-densities as low as those in natural forage (about 1,000 cal/g, as consumed) may limit growth of juvenile red drum even when that feed is available in excess of demand, especially under conditions of elevated temperature and dissolved oxygen concentration. Impacts of this
project include improved strategies for managing red drum in ponds for stock enhancement and for food-fish production.
Impacts
Model of fish performance is being used as a tool for planning marine fish stock enhancement in Texas.
Publications
- NEILL, W.H., BRANDES, T.S., BURKE, B.J., CRAIG, S.R., DIMICHELE, L.V., DUCHON, K., EDWARDS, R.E., FONTAINE, L.P., GATLIN III, D.M., HUTCHINS, C., MILLER, J.M., PONWITH, B.J., STAHL, C.J., TOMASSO, J.R., and VEGA, R.R. 2004. Ecophys.Fish: A simulation model of fish growth in time-varying environmental regimes. Reviews in Fisheries Science 12:233-288.
- NEILL, W.H., OBORNY JR., E.L., CRAIG, S.R., MATLOCK, M.D., and GATLIN III, D.M. 2003. Estimating metabolism of fish in aquacultural production systems. International Journal of Recirculating Aquaculture 4:25-32.
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Progress 01/01/03 to 12/31/03
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual fish, to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Activity in 2003 focused on preparation and submission of a major ms. that integrated findings from the past several years of ecophysiological research. This 127-page ms., entitled "Ecophys.Fish: A simulation model of fish growth in time-varying environmental regimes" describes the simulation model, its theoretical basis, its parameterization for two species of fish (the marine red drum Sciaenops ocellatus and the freshwater bluegill Lepomis macrochirus), and field tests of model efficacy. The ms. is now under review for publication in the international journal Ecological Modelling. Implications of the model already have led to a proposal for the next phase of our research, which will focus on
ecophysiological effects of cyclic environmental regimes; the research will be funded by Sea Grant.
Impacts
Model of fish performance is being used as a tool for planning marine fish stock enhancement in Texas.
Publications
- NEILL, W.H., OBORNY JR., E.L., CRAIG, S.R., MATLOCK, M.D., and GATLIN III, D.M. 2003. Estimating metabolism of fish in aquacultural production systems. International Journal of Recirculating Aquaculture.
- AKIN, S., and NEILL, W.H. 2003. Routine metabolism of mosquitofish at three different salinities. Texas Journal of Science 55:255-262.
- HUR, J.W., CHOI, C.Y., CHANG, Y.J., and NEILL, W.H. 2003. Effects of confinement and transport stress on physiological condition in olive flounder. Journal of Aquaculture 16:135-141.
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Progress 01/01/02 to 12/31/02
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Activity in 2002 focused on integrating research findings from the past several years in the form of a simulation model that represents the effects of environmental factors on fish growth. This model, its theoretical basis, its parameterization for two species of fish (the marine red drum Sciaenops ocellatus and the freshwater bluegill Lepomis macrochirus), and field tests of its efficacy have been described in a 150-page ms. entitled Ecophys.Fish: A simulation model of fish growth in time-varying environmental regimes. The ms. is now under review by the co-authors. An extended abstract of the ms. already has been published, in the proceedings of the most recent International Congress on the Biology of
Fish.
Impacts
Model of fish performance is being used as a tool for planning marine fish stock enhancement in Texas.
Publications
- Neill, W.H., Miller, J.M. Vega, R.R. and Fontaine, L.P. 2002. A simulation model of fish growth in time varying environmental regimes. Developments in Understanding Fish Growth, p. 97-101. In Developments in Understanding Fish Growth, B. Small and D. MacKinlay, eds. International Congress on the Biology of Fish, University of British Columbia, Vancouver,B.C., Canada. Physiology Section, American Fisheries Society.
- Fontaine, L.P., Neill. W.H., and Clark, K.W. 2002. Fish performance ecoassay of urbanizing streams in the San Antonio River Basin. Enviroinmental stress and health in fish, p. 55-58.In Environmental stress and health in fish, S.M. Adams, B. Barton, and D. MacKinlay, eds. International Congress on the Biology of Fish, University of British Columbia, Vancouver, B.C., Canada. Physiology Section, American Fisheries Society.
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Progress 01/01/01 to 12/31/01
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Research in 2001 focused on ecoassays of habitat quality for fish production. Performance both of freshwater and marine fish (bluegill and red drum, respectively) in field cage-trials was interpreted via laboratory bioassays of metabolic capacity and an ecophysiological simulation model that permitted the observed variation in fish survival and growth to be partitioned into effects of monitored environmental variables and those of residual environmental quality. The preliminary conclusion is that the majority of variation, both in survival and growth, is associated with temporal changes in water temperature and dissolved oxygen. However, more subtle variation in environment, resolvable via bioassay of
metabolic capacity, accounts for a very significant fraction of the variation in fish performance. In the case of winter cage trials with red drum, modeled growth's goodness-of-fit was improved 28 % by incorporating effects of residual environmental quality estimated via bioassay.
Impacts
Model of fish performance is being used as a tool for planning marine fish-stock enhancement in Texas.
Publications
- JIANG, D.-H., LAWRENCE, A.L., NEILL, W.H., and GONG, H.. 2000. Effects of temperature and salinity on nitrogenous excretion by. Journal of Experimental Marine Biology and Ecology 253:193-209.
- VELASCO, M., LAWRENCE, A.L., and NEILL, W.H. 2001. Comparison of survival and growth of postlarvae reared in static and recirculating culture systems. Texas J. Sci. 53:227-338.
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Progress 01/01/00 to 12/31/00
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Research in 2000 focused on further field-evaluation of an ecophysiological model designed to simulate fish growth in habitats with varying food, oxygen, temperature, salinity, and pH. The model has its basis in F.E.J. Frys metabolic scope concept, coupled with conventional bioenergetics theory. Versions of the model parameterized for the euryhaline red drum and freshwater bluegill have performed equally well, both accounting for upwards of 90 % of variation in growth of fish caged in environmentally heterogeneous habitats. Moreover, we now have learned how to use automated respirometry data from the lab, to calibrate the model for effects of residual environmental variation. Most recently, the model has
been augmented to accommodate responses to lethal and directive factors. The consequent virtual fish has such realistic capacities that it is being used as the subject of simulated experiments performed by undergraduate students in our senior-level fish biology course.
Impacts
The ecophysiological model of fish performance is being used both as a tool for planning marine fish-stock enhancement in Texas, and to provide virtual subjects for experiments performed by undergraduate fisheries students at Texas A&M University.
Publications
- Wu, H., Li, B.L., Springer, T.A., and Neill, W.H. 2000. Modelling animal movement as a persistent random walk in two dimensions: expected magnitude of net displacement. Ecological Modelling 132:115-124.
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Progress 01/01/99 to 12/31/99
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Research in 1999 focused on further field-evaluation of an ecophysiological model designed to simulate fish growth in habitats with varying food, oxygen, temperature, salinity, and pH. The model has its basis in F.E.J. Fry's metabolic scope concept, coupled with conventional bioenergetics theory; parameterization of the model had been accomplished via a series of lab experiments performed in prior years. Tests with red drum caged both in coastal hatchery ponds and in the estuary near Corpus Christi, TX, provided further support for the model's utility as a tool for interpreting and accurately predicting the effects of mutivariate environment on red drum growth, over periods up to six months and to fish
sizes over 600 g. Now, attention is turning to augmentation of the red drum model so that it can accommodate responses to lethal and directive factors, and to reparameterization of the basic model for the freshwater bluegill. The bluegill version of the model will be used to interpret metabolic-scope data from fish acclimatized in urbanizing streams of the San Antonio (TX) River basin, in the context of an EPA-funded study of watershed-restoration methodology.
Impacts
This project is to provide a better sceitnific basis for fisheries mansgement and aquacultural production of fish, via physiological experimentation and computer simulation.
Publications
- WU, H., LI, B.L., SPRINGER, T.A., and NEILL, W.H. 1999. In Press. Modelling animal movement as a persistent random walk in two dimensions: expected magnitude of net displacement. Ecological Modelling.
- KAMPS, R.H., and NEILL, W.H.. 1999. Aquacultural effluents: Directive signals to the system downstream? Journal of Chemical Ecology 25:2041-2050.
- RITVO, G., SPEED, F.M., NEILL, W.H., DIXON, J.B., LAWRENCE, A.L., and SAMOCHA T.M. 1999. Regression analysis of soil chemical composition for two shrimp farms in Texas. Journal of the World Aquaculture Society 30:26-35.
- BUENTELLO, J.A., GATLIN, D.M. III, and NEILL, W.H. 1999. In Press. Effects of water temperature and dissolved oxygen on daily feed consumption, feed utilization and growth of channel catfish. Aquaculture.
- DOOLEY, K.E., and NEILL, W.H.. 1999. In Press. Systems modeling by interdisciplinary teams: Innovative approaches to distance education. Journal of Natural Resources and Life Sciences Education.
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Progress 01/01/98 to 12/31/98
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Research in 1998 focused on field tests of an ecophysiological model designed to simulate red drum growth in habitats with varying food, oxygen, temperature, salinity, and pH. The model has its basis in F.E.J. Fry's metabolic scope concept, coupled with conventional bioenergetics theory; parameterization of the model had been accomplished via a series of lab experiments performed in prior years. Predictions of short-term (5-7 days) growth in early juvenile red drum compared very favorably with that observed in environmentally monitored cages. Two such cage trials were performed, one in a hatchery pond at the CCA/CPL Marine Development Center in Corpus Christi, TX, and the other at two contrasting sites
in the Packery Channel area of Corpus Christi Bay. The Packery Channel test was particularly heartening, because the model predicted no growth at the environmentally bad site, where growth was, in fact, slightly negative, and a 31.5 % increase in median weight (4.5 % per day, from 0.15 g) at the good site--which was exactly what was observed. A simulation of red drum growth over the longer term also agreed with observation: Environmental data from Texas Water Development Board's website for were used to simulate over-winter growth of first-year red drum in Lavaca Bay, TX, during 1990-91, for comparison with sizes observed in a sample of age-1 red drum collected by Texas Parks and Wildlife Department in mid-June 1991; predicted size was 123 g, and median observed size was 127 g (range, 83-142 g).
Impacts
(N/A)
Publications
- MILLER, J.M., NEILL, W.H., DUCHON, K.A., and ROSS, S.W. 1998. In Press. Ecophysiological determinants of secondary production in salt marshes: A simulation study. Proceedings of the National (U.S.) Symposium on Coastal Marsh Ecology and Restoration.
- ANDERSON, A.A., and NEILL, W.H. 1998. Thermal preference of tailwater vs. non-tailwater populations of Etheostoma spectabile. Copeia 1998:226-230.
- RITVO, G., SAMOCHA, T.M., LAWRENCE, A.L., and NEILL, W.H. 1998. Growth of Penaeus vannamei on soils from various Texas shrimp farms, under laboratory conditions. Aquaculture 163:101-110.
- RITVO, G., DIXON. J.B., LAWRENCE, A.L., SAMOCHA, T.M., NEILL, W.H., and SPEED, M.F. 1998. In Press. Accumulation of chemical elements in Texas shrimp pond soils. Journal of the World Aquaculture Society.
- RITVO, G., DIXON, J.B., SAMOCHA, T.M., LAWRENCE, A.L., and NEILL, W.H. 1998. In Press. Low-cost experimental unit and growth medium for testing soil effects on shrimp culture. Aquacultural Engineering.
- VELASCO, M., LAWRENCE, A.L., and NEILL, W.H. 1998. Development of a static-water ecoassay with microcosm tanks for postlarval Litopenaeus vannamei. Aquaculture 161:79-87.
- VELASCO, M., LAWRENCE, A.L., and NEILL, W.H. 1998. Effects of dietary phosphorus level and inorganic source on survival and growth of Penaeus vannamei postlarvae in zero-water exchange culture tanks. Aquatic Living Resources 11:29-33.
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Progress 01/01/97 to 12/31/97
Outputs
This project seeks broad understanding of fish-production systems, with emphasis on propagation of environmental effects through the individual to the levels of population and community; particular attention is directed to feed-back loops between fish and environment. Research in 1997 moved toward tests of an ecophysiological model of fish production in habitats with varying food, oxygen, temperature, and salinity. F.E.J. Frys metabolic scope concept was coupled with conventional bioenergetics to provide a theoretical basis for the model. The models central rule is this: Fish eat all feed presented or until available oxygen becomes insufficient to support the processing of more feed (metabolic scope is exceeded); the fish then partition the consumed feed energy and substrates in the usual ways (conventional bioenergetics) between various obligatory activities and growth; if obligatory activities cost more than available feed energy, the fish metabolizes its biomass
and loses weight; if obligatory activities cost more than available metabolic scope, the fish dies. Time-varying oxygen, temperature, and salinity are accommodated as limiting, controlling, and loading effects on metabolism and, thus, on metabolic scope; food insufficiencies limit conversion of metabolic scope into growth. Lab experiments have yielded model-parameter estimates for red drum, and the model has been implemented in STELLA II for simulation. Plans and funding (Sea Grant) were developed for field tests of the model, both in commercial-aquaculture and natural-fishery settings. Hatchery/nursery problems at our collaborating commercial-aquaculture facility delayed the test there until 1998. On the other front, activities began in October 1997, with a successful release of 230,000 0.3-g hatchery-produced juvenile red drum into Corpus Christi Bay. Simulated and observed growth rates of these fish over 35 days were quite similar, being in each case about 4 % per day.
Impacts
(N/A)
Publications
- RITVO, G., NEILL, W.H., LAWRENCE, A.L., and SAMOCHA, T.A. 1998. Turbidity related to shrimp size in tanks with soil substrate. Aquacultural Engineering. In press.
- VELASCO, M., LAWRENCE, A.L., and NEILL, W.H. 1998. Development of a static-water ecoassay with microcosm tanks for postlarval Penaeus vannamei. Aquaculture.
- MILLER, J.M., NEILL, W.H., and DUCHON, K.A. 1997. An ecophysiological model for predicting performance of released fish. Bulletin of the National Research Institute of Aquaculture (Japan). ANDERSON, A.A., and NEILL, W.H. 1998. Thermal preference of tailwater vs. non-tailwater populations of Etheostoma spectabile. Copeia. In press.
- KAMPS, R.A. 1996. Bioassimilation versus nitrification for the removal of ammonia in aquaculture biofilters. M.S. thesis, Texas A&M University, College Station, TX. 65 p.
- FORSBERG, J.A., DORSETT, P.W., and NEILL, W.H. 1996. Survival and growth of red drum Sciaenops ocellatus in saline groundwaters of west Texas USA. Journal of the World Aquaculture Society 27:462-474.
- FORSBERG, J.A., and NEILL, W.H. 1997. Saline groundwater as an aquaculture medium: Physiological studies on the red drum, Sciaenops ocellatus. Environmental Biology of Fishes 49:119-128.
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Progress 01/01/96 to 12/30/96
Outputs
This project seeks broad understanding of fish-production systems. Research in 1996 focused on development of an oxy-bioenergetic model of fish production in habitats with varying oxygen, temperature, and salinity. F.E.J. Fry's "metabolic scope" concept was coupled with conventional bioenergetics to provide a theoretical basis for the model. The model's central rule is this: Fish eat all feed presented or until available oxygen becomes insufficient to support the processing of more feed (metabolic scope is exceeded); the fish then partition the consumed feed energy and substrates in the usual ways (conventional bioenergetics) between various obligatory activities and growth; if obligatory activities cost more than available feed energy, the fish metabolizes its biomass and loses weight; if obligatory activities cost more than available metabolic scope, the fish dies. Time-varying oxygen, temperature, and salinity are accommodated as limiting, controlling, and loading
effects on metabolism and, thus, on metabolic scope. Lab experiments have yielded model-parameter estimates for red drum, and the model is being implemented in STELLA II for simulation.
Impacts
(N/A)
Publications
- VELASCO, M., LAWRENCE, A. L., NEILL, W.H. In press. Development of a static-waterecoassay with microcosm tanks for postlarval Penaeus vannamei. Aquaculture.
- FORSBERG, J.A., DORSETT, P. W., NEILL, W.H. In press. Survival and growth of red drum Sciaenops ocellatus in saline groundwaters of west Texas USA. Journal of the World Aquaculture Society.
- FORSBERG, J. A., NEILL, W.H. In press. Saline groundwater as an aquaculture medium:Physiological studies on the red drum Sciaenops ocellatus. Environmental Biology of Fishes.
- FLOOD, L.P., CARVAN, M.J. III, JAEGER, L., BUSBEE, D.L., GATLIN, D.M. III, NEILL, W.H. 1996. Reduction in hepatic microsomal P-450 and related catalytic activity in farm-raised red drum. Journal of Aquatic Animal Health 8:13-21.
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Progress 01/01/95 to 12/30/95
Outputs
This project seeks broad understanding of fish-production systems, emphasis on propagation of environmental effects through individual to the levels of population & community; particular attention directed to feed-back loops between fish & environment. Intensive aquaculture is primary application-focus, because it offers extreme cases for studying such interactions; however, important issues of wild-fish conservation & management, such as recruitment, also are targeted. Three research thrusts ended in 1995: 1) Lab experiments & pond production-trials indicated that saline aquaculture in west Texas is technically quite feasible, despite characteristically high sulfate levels in water & soil, but that such aquaculture is economically problematic, with negative internal rates of return on investment for the most reasonable production scenarios. 2) A series of lab & field research efforts on cold- kill & its management fish production systems, culminated in a general model
of cold acclimation & lethal resistance in cold-intolerant fishes & in development of efficient, economical thermal-refuge technology. 3) An experimental & modeling analysis of salinity responses of paddlefish suggested little likelihood that paddlefish stocked into an east Texas river will move into other river systems via the intercoastal waterway where salinities exceed 4 ppt, well short of the 96-h median tolerance limit of 8 ppt.
Impacts
(N/A)
Publications
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