@article{craig_rice_crowder_nadeau_2007, title={Density-dependent growth and mortality in an estuary-dependent fish: an experimental approach with juvenile spot Leiostomus xanthurus}, volume={343}, ISSN={["1616-1599"]}, DOI={10.3354/meps06864}, abstractNote={The abundance of demersal marine fishes is a function of both pre-settlement processes that influence recruitment to benthic juvenile habitats, as well as post-settlement density-dependent processes that act during the juvenile stage. Few studies have investigated density-dependence for fishes that spawn offshore and recruit to inshore estuaries for the juvenile stage prior to returning to offshore waters as adults (i.e. estuary-dependent). We conducted 2 replicated experiments at differ- ent spatial scales to test for density-dependent growth and mortality in juvenile spot Leiostomus xan- thurus, a common estuary-dependent species. In the small-scale experiment, we stocked spot in 1 m 2 cages in a marsh creek at densities of 2, 5, and 10 fish m -2 and determined their growth and mortal- ity after 51 d. In the large-scale experiment, we stocked spot in 79 m 2 pond sections at 2, 5, and 10 fish m -2 and determined their growth and mortality after 52 d. We sampled benthic infauna at the end of the pond experiment to determine if prey availability mediated the effects of density on spot growth and mortality. Average spot growth rates decreased 83 to 97% and mortality increased 2- to 4-fold as density increased from 2 to 10 fish m -2 . The density of benthic infauna at the end of the pond exper- iment was inversely related to spot density, consistent with competition for food as the underlying mechanism. Estimates of spot density compiled from the literature indicate that the density-depen- dent effects we observed occurred within the range of reported field densities. Our results provide strong experimental support for the hypothesis that density-dependent processes during the demer- sal juvenile stage in estuaries can modify patterns in the abundance of spot, and perhaps other estu- ary-dependent species, that are established prior to settlement.}, journal={MARINE ECOLOGY PROGRESS SERIES}, author={Craig, J. Kevin and Rice, James A. and Crowder, Larry B. and Nadeau, David A.}, year={2007}, pages={251–262} }
 @article{craig_crowder_henwood_2005, title={Spatial distribution of brown shrimp (Farfantepenaeus aztecus) on the northwestern Gulf of Mexico shelf: effects of abundance and hypoxia}, volume={62}, ISSN={["1205-7533"]}, DOI={10.1139/F05-036}, abstractNote={ We used fishery-independent hydrographic and bottom trawl surveys on the northwestern Gulf of Mexico shelf from 1983–2000 to test for density dependence and effects of hypoxia (dissolved oxygen ≤ 2.0 mg·L–1) on the spatial distribution of brown shrimp (Farfantepenaeus aztecus). Spatial distribution of shrimp was positively related to abundance on the Texas shelf but negatively related to abundance on the Louisiana shelf. Density dependence was weak, however, and may have been due to factors other than density-dependent habitat selection. Males were distributed over a broader area and further offshore than were females, though differences in spatial distribution between sexes were not large (~10%–15%). Large-scale hypoxia (up to ~20 000 km2) on the Louisiana shelf occurs in regions of typically high shrimp density and results in substantial habitat loss (up to ~25% of the Louisiana shelf), with shifts in distribution and associated high densities both inshore and offshore of the hypoxic region. We discuss these results in terms of the generality of density-dependent spatial distributions in marine populations and potential consequences of habitat loss and associated shifts in distribution due to low dissolved oxygen. }, number={6}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Craig, JK and Crowder, LB and Henwood, TA}, year={2005}, month={Jun}, pages={1295–1308} }
 @article{diamond_cowell_crowder_2000, title={Population effects of shrimp trawl bycatch on Atlantic croaker}, volume={57}, ISSN={["0706-652X"]}, DOI={10.1139/cjfas-57-10-2010}, abstractNote={We used stage-within-age based matrix models of Atlantic croaker (Micropogonias undulatus) in the Gulf of Mexico and the South and Mid-Atlantic bights to explore the population-level impacts of shrimp trawl bycatch on estuarine-dependent fishes and to investigate tradeoffs between directed adult fisheries and bycatch mortality. The Gulf model reflected a rapidly declining population, while the Atlantic population showed a modest decline. Elasticity analyses indicated that both populations were more sensitive to the summed survival of adults than first-year survival, particularly in the Gulf. Contrary to our expectations, bycatch mortality on late juveniles was not the most important factor affecting either population of Atlantic croaker, and this result was robust to uncertainty in both adult and late juvenile mortality estimates. Both populations were most sensitive to ocean larva mortality, followed by mortality of estuary larvae and adults in the Gulf and of early juveniles and adults in the Atlantic. ...}, number={10}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Diamond, SL and Cowell, LG and Crowder, LB}, year={2000}, month={Oct}, pages={2010–2021} }
 @article{diamond_crowder_cowell_1999, title={Catch and bycatch: The qualitative effects of fisheries on population vital rates of Atlantic croaker}, volume={128}, ISSN={["1548-8659"]}, DOI={10.1577/1548-8659(1999)128<1085:CABTQE>2.0.CO;2}, abstractNote={Abstract Bycatch in shrimp trawl fisheries can make up 60–80% of the catch by weight. Finfish taken incidentally in shrimp trawls include juveniles of species that are valuable in directed fisheries as adults. Atlantic croaker Micropogonias undulatus is commonly caught as bycatch in shrimp trawls and has also been a target species in both the Gulf of Mexico (the Gulf) and the South and Middle Atlantic bights (the Atlantic). The catch of Atlantic croaker, including bycatch, has historically been at least three times higher in the Gulf than in the Atlantic. Gulf fisheries, including the directed industrial fishery, have primarily harvested juvenile fish. In contrast, the most intensive fisheries in the Atlantic have targeted adult fish. We hypothesized that population-level effects of exploitation differ qualitatively between fisheries that take primarily juveniles and fisheries that target adults, even in the face of bycatch of juveniles. We compiled data on Atlantic croaker fisheries, life history paramet...}, number={6}, journal={TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY}, author={Diamond, SL and Crowder, LB and Cowell, LG}, year={1999}, month={Nov}, pages={1085–1105} }
 @article{letcher_priddy_walters_crowder_1998, title={An individual-based, spatially-explicit simulation model of the population dynamics of the endangered red-cockaded woodpecker, Picoides borealis}, volume={86}, ISSN={["0006-3207"]}, DOI={10.1016/S0006-3207(98)00019-6}, abstractNote={Spatially-explicit population models allow a link between demography and the landscape. We developed a spatially-explicit simulation model for the red-cockaded woodpecker, Picoides borealis, an endangered and territorial cooperative breeder endemic to the southeastern United States. This kind of model is especially appropriate for this species because it can incorporate the spatial constraints on dispersal of helpers, and because territory locations are predictable. The model combines demographic data from a long-term study with a description of the spatial location of territories. Sensitivity analysis of demographic parameters revealed that population stability was most sensitive to changes in female breeder mortality, mortality of female dispersers and the number of fledglings produced per brood. Population behavior was insensitive to initial stage distribution; reducing the initial number of birds by one-half had a negligible effect. Most importantly, we found that the spatial distribution of territories had as strong an effect on response to demographic stochasticity as territory number. Populations were stable when territories were highly aggregated, with as few as 49 territories. When territories were highly dispersed, more than 169 territories were required to achieve stability. Model results indicate the importance of considering the spatial distribution of territories in management plans, and suggest that this approach is worthy of further development.}, number={1}, journal={BIOLOGICAL CONSERVATION}, author={Letcher, BH and Priddy, JA and Walters, JR and Crowder, LB}, year={1998}, month={Oct}, pages={1–14} }
 @article{mccollum_crowder_mccollum_1998, title={Complex interactions of fish, snails, and littoral zone periphyton}, volume={79}, number={6}, journal={Ecology (Brooklyn, New York, N.Y.)}, author={McCollum, E. W. and Crowder, L. B. and McCollum, S. A.}, year={1998}, pages={1980–1984} }
 @article{cowell_crowder_kepler_1998, title={Density-dependent prenatal androgen exposure as an endogenous mechanism for the generation of cycles in small mammal populations}, volume={190}, ISSN={["1095-8541"]}, DOI={10.1006/jtbi.1997.0543}, abstractNote={Small mammal populations exhibit cyclic fluctuations in their population densities. Several hypotheses regarding the mechanisms underlying these population cycles have been advanced, but none has yet gained general approval. We propose here an endogenous mechanism based on the masculinization of female offspring in response to increased population levels. High population levels trigger the non-specific stress response resulting in high levels of circulating androgens in individuals of the population, including pregnant females. These androgens masculinize female offspring in utero, thereby reducing the reproductive capacity of the next generation and subsequently the population size. We have developed and analysed a mathematical model to investigate the possible role of prenatal androgen exposure in the generation of limit cycles. We find the locus of Hopf bifurcations for this model and show that limit cycles depend on three parameters: (1) the delay between birth and sexual maturation; (2) the slope of the function that relates average prenatal androgen exposure to total population density; and (3) the difference between the maximum birth rates of the low- and high-androgen exposed females. We derive the analytical form relating these parameters at the Hopf-bifurcation locus and discuss its biological ramifications. In brief, in each of these three parameters is sufficiently large, population cycles will results from the endogenous mechanism proposed.Copyright 1998 Academic Press Limited Copyright 1998 Academic Press Limited}, number={1}, journal={JOURNAL OF THEORETICAL BIOLOGY}, author={Cowell, LG and Crowder, LB and Kepler, TB}, year={1998}, month={Jan}, pages={93–106} }
 @article{crowder_squires_rice_1997, title={Nonadditive effects of terrestrial and aquatic predators on juvenile estuarine fish}, volume={78}, DOI={10.1890/0012-9658(1997)078[1796:neotaa]2.0.co;2}, abstractNote={Small fish frequently avoid large fish predators by moving into shallow refuges, but this can increase encounters with terrestrial piscivores. In previous experiments, we documented that juvenile spot (Leiostomus xanthurus) respond to southern flounder (Paralichthys lethostigma) by moving into shallow water. This might increase their risk of predation by birds. We conducted a pond-scale field experiment to test the hypothesis that predation by birds and flounder will have nonadditive effects on spot survival and size. We expected spot to have lower survival in the presence of both predators than expected based on their additive effects (i.e., facilitation among predators). The experiment was a 2 3 2 factorial with and without flounders and bird access. Flounder significantly reduced spot survival while birds did not, but there was a significant interaction effect. Spot survived better with both predators than expected based on adding separate predator effects. Mean spot growth rate was unaffected by treatment. Spot moved to shallow water in the presence of flounder and aggregated more tightly in the presence of birds. The observed nonadditive effects could have been due to interference between flounder and birds. However, because all the flounder in our experiments survived and their growth was unaffected by birds, we favor the idea that behavioral changes (increased aggregation) by spot to avoid bird pre- dation also further reduced their vulnerability to flounder. Our results suggest that modeling the effects of multiple predators will be more complicated than simply adding up the effects observed in experiments with single predators.}, number={6}, journal={Ecology (Brooklyn, New York, N.Y.)}, author={Crowder, L. B. and Squires, D. D. and Rice, J. A.}, year={1997}, pages={1796–1804} }
 @inbook{rice_crowder_marschall_1997, title={Predation on juvenile fishes: Dynamic interactions between size-structured predators and prey}, volume={21}, booktitle={Early life history and recruitment in fish populations (Fish and Fisheries series #21)}, publisher={London: Chapman & Hall}, author={Rice, J. A. and Crowder, L. B. and Marschall, E. A.}, editor={R. C. Chambers and Trippel, E. A.Editors}, year={1997}, pages={333–356} }
 @article{letcher_rice_crowder_binkowski_1997, title={Size- and species dependent variability in consumption and growth rates of larvae and juveniles of three freshwater fishes}, volume={54}, ISSN={["0706-652X"]}, DOI={10.1139/cjfas-54-2-405}, number={2}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={Letcher, BH and Rice, JA and Crowder, LB and Binkowski, FP}, year={1997}, month={Feb}, pages={405–414} }
 @misc{miller_crowder_rice_marschall_1988, title={LARVAL SIZE AND RECRUITMENT MECHANISMS IN FISHES - TOWARD A CONCEPTUAL-FRAMEWORK}, volume={45}, ISSN={["1205-7533"]}, DOI={10.1139/f88-197}, abstractNote={ Understanding the mechanisms controlling recruitment in fishes is a major problem in fisheries science. Although the literature on recruitment mechanisms is large and growing rapidly, it is primarily species specific. There is no conceptual framework to integrate the existing information on larval fish ecology and its relationship to survival and recruitment. In this paper, we propose an integrating framework based on body size. Although all larval fish are small relative to adult fish, total length at hatching differs among species by an order of magnitude. As many of the factors critical to larval survival and growth are size dependent, substantially different expectations arise about which mechanisms might be most important to recruitment success. We examined the evidence for the importance of size to feeding and starvation, to activity and searching ability, and to risk of predation. Regressions based on data from 72 species of marine and freshwater species suggest that body size is an important factor that unifies many of the published observations. A conceptual framework based on body size has the potential to provide a useful integration of the available data on larval growth and survival and a focus for future studies of recruitment dynamics. }, number={9}, journal={CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES}, author={MILLER, TJ and CROWDER, LB and RICE, JA and MARSCHALL, EA}, year={1988}, month={Sep}, pages={1657–1670} }
 @article{crouse_crowder_caswell_1987, title={A STAGE-BASED POPULATION-MODEL FOR LOGGERHEAD SEA-TURTLES AND IMPLICATIONS FOR CONSERVATION}, volume={68}, ISSN={["1939-9170"]}, DOI={10.2307/1939225}, abstractNote={Management of many species is currently based on an inadequate understanding of their population dynamics. Lack of age—specific demographic information, particularly for long—lived iteroparous species, has impeded development of useful models. We use Lefkovitch stage class matrix model, based on preliminary life table developed by Frazer (1983), to point to interim management measures and to identify those data most critical to refining our knowledge about the population dynamics of threatened loggerhead sea turtles (Caretta caretta). Population projections are used to examine the sensitivity of Frazer's life table to variations in parameter estimates as well as the likely response of the population to various management alternatives. Current management practices appear to be focused on the least responsive life stage, eggs on nesting—beaches. Alternative protection efforts for juvenile loggerheads,such as using turtle excluder devices (TEDs), may be far more effective.}, number={5}, journal={ECOLOGY}, author={CROUSE, DT and CROWDER, LB and CASWELL, H}, year={1987}, month={Oct}, pages={1412–1423} }