Texas Sea Grant College Program
otherCollege Station, Texas, United States
Research output, citation impact, and the most-cited recent papers from Texas Sea Grant College Program (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Texas Sea Grant College Program
The consensus that humans are causing recent global warming is shared by 90%-100% of publishing climate scientists according to six independent studies by co-authors of this paper. Those results are consistent with the 97% consensus reported by Cook et al (Environ. Res. Lett. 8 024024) based on 11 944 abstracts of research papers, of which 4014 took a position on the cause of recent global warming. A survey of authors of those papers (N=2412 papers) also supported a 97% consensus. Tol (2016 Environ. Res. Lett. 11 048001) comes to a different conclusion using results from surveys of nonexperts such as economic geologists and a self-selected group of those who reject the consensus. We demonstrate that this outcome is not unexpected because the level of consensus correlates with expertise in climate science. At one point, Tol also reduces the apparent consensus by assuming that abstracts that do not explicitly state the cause of global warming ('no position') represent nonendorsement, an approach that if applied elsewhere would reject consensus on well-established theories such as plate tectonics. We examine the available studies and conclude that the finding of 97% consensus in published climate research is robust and consistent with other surveys of climate scientists and peer-reviewed studies.
Abstract A continuous record of organic carbon δ 13 C from a buried soil sequence in south-central Texas demonstrates: 1) strong coupling between marine and adjacent continental ecosystems in the late Pleistocene as a result of glacial meltwater entering the Gulf of Mexico and 2) ecosystem decoupling in the Holocene associated with a reduction of meltwater and a shift in global circulation patterns. In the late Pleistocene, reduction in C 4 plant productivity correlates with two well-documented glacial meltwater pulses (∼15,000 and 12,000 14 C yr B.P.), indicating a cooler-than-present adjacent continental environment. Increased C 4 production between 11,000 and 10,000 14 C yr B.P. suggests that the Younger Dryas was a warm interval responding to the diversion of glacial meltwater away from the Mississippi River. With waning meltwater flow, C 4 productivity generally increased throughout the Holocene, culminating in peak warm intervals at ∼5000 and 2000 14 C yr B.P. Shifts in the abundances of C 3 –C 4 plants through the late Quaternary show no correlation to ecophysiological responses to atmospheric CO 2 concentration.
The Useful to Usable (U2U) project was a six-year research and extension project funded by the United States Department of Agriculture to provide both useful and usable climate information for the agricultural (corn) sector in the Midwestern United States. The project adopted an extensive co-production of knowledge and decision-making approach that involved intense iteration with potential end-users, including farmers and a variety of pro- fessional agricultural advisors, through focus groups and surveys, feedback at outreach events, and frequent informal interactions to develop both decision support tools and delivery mechanisms that met stakeholder needs. This overview paper for this special issue illustrates some key ways that the co-production process informed the overall project. Subsequent papers in the special issue span the different objectives of the U2U project, including social, climate, and agronomic sciences. A brief overview of these papers is pre- sented here.
Archaeological and ecological investigations in the Mirador Basin of northern Guatemala have recovered archaeological, phytolith, palynological, and pedological data relevant to the early occupation and development of Maya civilization in a specific environmental matrix. Fluctuation in vegetation types as evident in cores and archaeological profiles suggest that the seasonally wet, forested bajo environment currently found in the northern Peten was anciently more of a perennially wet marsh system that may have been heavily used and influenced by large Preclassic occupations. Data suggest that climatic and environmental factors correspond with the cultural process in the Mirador Basin, and research in progress is oriented to further elucidating these issues.
We analysed 20 boxes of, frozen imported bait-shrimp (China: Parapenaeopsis sp. and Metapenaeopsis sp.) and 8 boxes of native, frozen bait-shrimp (Gulf of Mexico: Litopenaeus setiferus and Farfantepenaeus duorarum) by RT-PCR or PCR for Taura syndrome virus (TSV), yellowhead virus/gill-associated virus (YHV/GAV), white-spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV). All 28 boxes of shrimp were negative for TSV, YHV/GAV and IHHNV; 2 boxes of imported bait-shrimp were WSSV-positive by 3 different PCR assays. Intramuscular injection of replicate groups of SPF (specific pathogen-free) L. vannamei juveniles with 2 different tissue homogenates prepared from the 2 WSSV-positive bait boxes resulted in 100% mortality of the test shrimp within 48 to 72 h post-injection. No mortality occurred among injected negative control groups. Histological and in situ hybridization analyses of 20 moribund treatment-shrimp demonstrated severe WSSV infections in each sample. Oral exposure of SPF L. vannamei postlarvae, PL (PL 25 to 30 stage; approximately 0.02 g) to minced tissue prepared from the 2 WSSV-positive bait-lots did not induce infection, possibly because of an insufficient infectious dose and/or viral inactivation resulting from multiple freeze-thaw cycles of the bait-shrimp during PCR testing. Use of an electric drill and collection of drill-tailings (tissue from approximately 20 to 30 shrimp) from frozen blocks of shrimp was successfully employed as an alternate tissue-sampling method without thawing. Our findings indicate that imported WSSV-infected bait shrimp, originating from China, are being sold in Texas for the purpose of sport fishing and represent a potential threat to freshwater and marine crustacean fisheries, as well as to coastal US shrimp farms.
James W. Avault, Jr. AVA Publishing Co., Baton Rouge, Louisiana. 1996. 889 pages. $99.95 (paper). (Available from the American Fisheries Society; AFS members receive a 10% discount.) Many attempts ...
The usefulness of climate information for agricultural risk management hinges on its availability and relevance to the producer when climate-sensitive decisions are being made. Climate information providers are challenged with the task of balancing forecast availability and lead time with acceptable forecast skill, which requires an improved understanding of the timing of agricultural decision making. Achieving a useful balance may also require an expansion of inquiry to include use of non-forecast climate information (i.e. historical climate information) in agricultural decision making. Decision calendars have proven valuable for identifying opportunities for using different types of climate information. The extent to which decision-making time periods are localized versus generalized across major commodity-producing regions is yet unknown, though, which has limited their use in climate product development. Based on a 2012 survey of more than 4770 agricultural producers across the U.S. Corn Belt region, we found variation in the timing of decision-making points in the crop year based on geographic variation as well as crop management differences. Many key decisions in the cropping year take place during the preceding fall and winter, months before planting, raising questions about types of climate information that might be best inserted into risk management decisions at that time. We found that historical climate information and long term climate outlooks are less influential in agricultural risk management than current weather, short term forecasts, or monthly climate projections, even though they may, in fact, be more useful to certain types of decision making.
This chapter contains sections titled: Beginnings of aquaculture Expansion prior to the mid-1800s The explosion of hatcheries Art becomes science Commercial finfish species development Shrimp culture Mollusk culture Controversy References
Abstract Aim Understanding the spatial ecology of animal movements is a critical element in conserving long‐lived, highly mobile marine species. Analyzing networks developed from movements of six sea turtle species reveals marine connectivity and can help prioritize conservation efforts. Location Global. Methods We collated telemetry data from 1235 individuals and reviewed the literature to determine our dataset's representativeness. We used the telemetry data to develop spatial networks at different scales to examine areas, connections, and their geographic arrangement. We used graph theory metrics to compare networks across regions and species and to identify the role of important areas and connections. Results Relevant literature and citations for data used in this study had very little overlap. Network analysis showed that sampling effort influenced network structure, and the arrangement of areas and connections for most networks was complex. However, important areas and connections identified by graph theory metrics can be different than areas of high data density. For the global network, marine regions in the Mediterranean had high closeness, while links with high betweenness among marine regions in the South Atlantic were critical for maintaining connectivity. Comparisons among species‐specific networks showed that functional connectivity was related to movement ecology, resulting in networks composed of different areas and links. Main conclusions Network analysis identified the structure and functional connectivity of the sea turtles in our sample at multiple scales. These network characteristics could help guide the coordination of management strategies for wide‐ranging animals throughout their geographic extent. Most networks had complex structures that can contribute to greater robustness but may be more difficult to manage changes when compared to simpler forms. Area‐based conservation measures would benefit sea turtle populations when directed toward areas with high closeness dominating network function. Promoting seascape connectivity of links with high betweenness would decrease network vulnerability.
Abstract: A simple spreadsheet model was used to evaluate potential water quality benefits of high‐density development. The question was whether the reduced land consumed by higher density development ( vs. standard suburban developments) would offset the worse water quality generated by a greater amount of impervious surface in the smaller area. Total runoff volume and per acre loadings of total phosphorous, total nitrogen, and total suspended solids increased with density as expected, but per capita loadings and runoff decreased markedly with density. For a constant or given population, then, higher density can result in dramatically lower total loadings than more diffuse suburban densities. The model showed that a simple doubling of standard suburban densities [to 8 dwelling units per acre (DUA) from about 3 to 5 DUA] in most cases could do more to reduce contaminant loadings associated with urban growth than many traditional stormwater best management practices (BMPs), and that higher densities such as those associated with transit‐oriented development could outperform almost all traditional BMPs, in terms of reduced loadings per a constant population. Because higher density is associated with vibrant urban life, building a better city may be the best BMP to mitigate the water quality damage that will accompany the massive urban growth expected for the next several decades.
The idea that interspecific variation in trophic morphology among closely related species effectively permits resource partitioning has driven research on ecological radiation since Darwin first described variation in beak morphology among Geospiza. Marine turtles comprise an ecological radiation in which interspecific differences in trophic morphology have similarly been implicated as a pathway to ecopartition the marine realm, in both extant and extinct species. Because marine turtles are charismatic flagship species of conservation concern, their trophic ecology has been studied intensively using stable isotope analyses to gain insights into habitat use and diet, principally to inform conservation management. This legion of studies provides an unparalleled opportunity to examine ecological partitioning across numerous hierarchical levels that heretofore has not been applied to any other ecological radiation. Our contribution aims to provide a quantitative analysis of interspecific variation and a comprehensive review of intraspecific variation in trophic ecology across different hierarchical levels marshalling insights about realised trophic ecology derived from stable isotopes. We reviewed 113 stable isotope studies, mostly involving single species, and conducted a meta-analysis of data from adults to elucidate differences in trophic ecology among species. Our study reveals a more intricate hierarchy of ecopartitioning by marine turtles than previously recognised based on trophic morphology and dietary analyses. We found strong statistical support for interspecific partitioning, as well as a continuum of intraspecific trophic sub-specialisation in most species across several hierarchical levels. This ubiquity of trophic specialisation across many hierarchical levels exposes a far more complex view of trophic ecology and resource-axis exploitation than suggested by species diversity alone. Not only do species segregate along many widely understood axes such as body size, macrohabitat, and trophic morphology but the general pattern revealed by isotopic studies is one of microhabitat segregation and variation in foraging behaviour within species, within populations, and among individuals. These findings are highly relevant to conservation management because they imply ecological non-exchangeability, which introduces a new dimension beyond that of genetic stocks which drives current conservation planning. Perhaps the most remarkable finding from our data synthesis is that four of six marine turtle species forage across several trophic levels. This pattern is unlike that seen in other large marine predators, which forage at a single trophic level according to stable isotopes. This finding affirms suggestions that marine turtles are robust sentinels of ocean health and likely stabilise marine food webs. This insight has broader significance for studies of marine food webs and trophic ecology of large marine predators. Beyond insights concerning marine turtle ecology and conservation, our findings also have broader implications for the study of ecological radiations. Particularly, the unrecognised complexity of ecopartitioning beyond that predicted by trophic morphology suggests that this dominant approach in adaptive radiation research likely underestimates the degree of resource overlap and that interspecific disparities in trophic morphology may often over-predict the degree of realised ecopartitioning. Hence, our findings suggest that stable isotopes can profitably be applied to study other ecological radiations and may reveal trophic variation beyond that reflected by trophic morphology.
Abstract Knowledge of the spatial distribution of populations is fundamental to management plans for any species. When tracking data are used to describe distributions, it is sometimes assumed that the reported locations of individuals delineate the spatial extent of areas used by the target population. Here we examine existing approaches to validate this assumption, highlight caveats, and propose a new method for a more informative assessment of the number of tracked animals (i.e. sample size) necessary to identify distribution patterns. We show how this assessment can be achieved by considering the heterogeneous use of habitats by a target species using the probabilistic property of a utilisation distribution. Our methods are compiled in the r package SDL filter . We illustrate and compare the protocols underlying existing and new methods using conceptual models and demonstrate an application of our approach using a large satellite tracking dataset of flatback turtles Natator depressus tagged with accurate Fastloc‐GPS tags ( n = 69). Our approach has applicability for the post hoc validation of sample sizes required for the robust estimation of distribution patterns across a wide range of taxa, populations and life‐history stages of animals.
We developed a Kemp’s ridley (Lepidochelys kempii) stock assessment model to evaluate the relative contributions of conservation efforts and other factors toward this critically endangered species’ recovery. The Kemp’s ridley demographic model developed by the Turtle Expert Working Group (TEWG) in 1998 and 2000 and updated for the binational recovery plan in 2011 was modified for use as our base model. The TEWG model uses indices of the annual reproductive population (number of nests) and hatchling recruitment to predict future annual numbers of nests on the basis of a series of assumptions regarding age and maturity, remigration interval, sex ratios, nests per female, juvenile mortality, and a putative ‘‘turtle excluder device effect’’ multiplier starting in 1990. This multiplier was necessary to fit the number of nests observed in 1990 and later. We added the effects of shrimping effort directly, modified by habitat weightings, as a proxy for all sources of anthropogenic mortality. Additional data included in our model were incremental growth of Kemp’s ridleys marked and recaptured in the Gulf of Mexico, and the length frequency of stranded Kemp’s ridleys. We also added a 2010 mortality factor that was necessary to fit the number of nests for 2010 and later (2011 and 2012). Last, we used an empirical basis for estimating natural mortality, on the basis of a Lorenzen mortality curve and growth estimates. Although our model generated reasonable estimates of annual total turtle deaths attributable to shrimp trawling, as well as additional deaths due to undetermined anthropogenic causes in 2010, we were unable to provide a clear explanation for the observed increase in the number of stranded Kemp’s ridleys in recent years, and subsequent disruption of the species’ exponential growth since the 2009 nesting season. Our consensus is that expanded data collection at the nesting beaches is needed and of high priority, and that 2015 be targeted for the next stock assessment to evaluate the 2010 event using more recent nesting and in-water data.
The Midwestern United States experienced a devastating drought in 2012, leading to reduced corn and soybean yields and increased instances of pests and disease. Climate change induced weather variability and extremes are expected to increase in the future, and have and will continue to impact the agricultural sector. This study investigated how agricultural trade publications portrayed the 2012 U.S. Midwestern drought, whether climate change was associated with drought, and whether these publications laid out transformative adaptation measures farmers could undertake in order to increase their adaptive capacity for future climate uncertainty. We performed a content analysis of 1000 media reports between April 1, 2012 and March 31, 2014, sampled from ten agricultural trade publications. The results lead us to suggest that trade publications' 2012 U.S. Midwestern drought discussion lacked information that would allow farmers and agricultural advisors to assess climate change risk and subsequent potential adaptive management strategies. Agricultural risk from climate change is very real, and farmers will need to adapt. The agricultural trade publications studied missed an opportunity to convey risk from climate change and the transformative adaptation practices necessary for a sustainable and resilient agricultural system.
Abstract The development of motor synchrony in dolphins has been described qualitatively, but seldom quantified. We provide a detailed description of the development of synchrony in 12 calves for periods ranging from birth to a few days up to 22 wk. We observed the presence of synchrony, relative positions, and proximity and undertook a videotape analysis of one calf for initiations/terminations of synchrony, response time to breaks in synchrony, and the development of complex behaviors by the calf relative to synchrony. Synchrony was uniformly present more than 90% of the time during month 1, then began to decline gradually. Echelon position was most frequent but calves also spent time in infant position. Initially all calves were most frequently in direct physical contact with their mothers, but by 2 wk of age, all pairs were more likely to be near each other (<0.5 m) without touching. Behavioral complexity increased gradually over the study, and adults frequently performed behaviors during synchronous swimming, providing opportunities for social learning. Synchrony is a predominant behavior in mother‐calf interactions, and we speculate that it may be an important mechanism through which calves learn from their mothers via their tandem interactions with the environment.
Eastern box turtles (Terrepene carolina carolina) are often negatively impacted by anthropogenic activities, such as mortality caused by vehicles or agricultural equipment. However, studies investigating human perceptions of a particular species are often directed toward charismatic megafauna or polarizing species, such as wolves. Given the worldwide decline of reptiles and box turtles’ high potential for human-caused mortality, there is a need to investigate the factors affecting public perception of this species. This article investigated respondents’ value orientations, attitudes, beliefs, and behavioral intentions directed at box turtles. Mail surveys were distributed to 1,378 respondents of the Blue River Watershed in southern Indiana. Respondents had generally positive attitudes toward the species. However, both attitudes and behavioral intentions were significantly influenced by respondents’ wildlife value orientations, indicating that wildlife value orientations can serve as a predictor of attitudes even when directed at well-liked, but non-charismatic imperiled species.
The objective of the Coastal and Inland Flooding Observation and Warning (CI-FLOW) project is to prototype new hydrometeorologic techniques to address a critical NOAA service gap: routine total water level predictions for tidally influenced watersheds. Since February 2000, the project has focused on developing a coupled modeling system to accurately account for water at all locations in a coastal watershed by exchanging data between atmospheric, hydrologic, and hydrodynamic models. These simulations account for the quantity of water associated with waves, tides, storm surge, rivers, and rainfall, including interactions at the tidal/surge interface. Within this project, CI-FLOW addresses the following goals: i) apply advanced weather and oceanographic monitoring and prediction techniques to the coastal environment; ii) prototype an automated hydrometeorologic data collection and prediction system; iii) facilitate interdisciplinary and multiorganizational collaborations; and iv) enhance techniques and technologies that improve actionable hydrologic/hydrodynamic information to reduce the impacts of coastal flooding. Results are presented for Hurricane Isabel (2003), Hurricane Earl (2010), and Tropical Storm Nicole (2010) for the Tar–Pamlico and Neuse River basins of North Carolina. This area was chosen, in part, because of the tremendous damage inflicted by Hurricanes Dennis and Floyd (1999). The vision is to transition CI-FLOW research findings and technologies to other U.S. coastal watersheds.
Marine turtles are both flagship species of conservation concern and indicators of ocean health. As highly migratory species, and despite substantial research effort focusing on nesting females and satellite tagging studies, we still know little about the trophic ecology and habitat use of immature stages and males. Consequently, marine turtle biologists began using stable isotope analyses in the last decade to elucidate various aspects of trophic ecology, including habitat use and trophic position. This has resulted in a burgeoning but largely disconnected literature of mostly single-species case studies. Here we comprehensively synthesize this body of work into a unified data repository, the MarTurtSI database. MarTurtSI contains stable isotope data from six of seven marine turtle species ranging from juveniles to adults, in different developmental, feeding, and breeding habitats across multiple ocean basins. MarTurtSI will be curated and updated with the aim of enabling continued comprehensive and global investigations into the trophic ecology of marine turtles especially in the face of climate change and other conservation challenges.
In the past, intensive shrimp farm effluents have been characterized as having an environmental impact, but with improvements in technology to control the factors that contribute to the impact, this situation has improved rapidly. In 1994, Texas shrimp farmers began to retrofit their farms and to reuse culture water. Farmers have found that they could reuse far more water than ever thought possible, and the process cleans the renewable natural resource. The management teams have led the way to sustainable, environmentally friendly shrimp farming in the USA by recirculating water and have cut their water use over time to filling ponds and evaporation replacement. In the process, farms have cut their stocking densities, use lower protein feeds, feed more frequently, have widened and deepened their discharge canals, have placed weirs or baffles in discharge canals to help settle the solids, have increased mechanical aeration in those canals and the ponds, and have increased production as a result. Recirculated water has been monitored on the farms and comparisons of intake versus average recirculation-system water have been made. Results show marked improvement in water quality when recirculation is employed. Because of these successes, farms are stocking more shrimp ponds in anticipation of equally successful future crops using the modified procedures.
ABSTRACT In order to test the feasibility of producing a breeding stock of nonindigenous penaeid shrimp in closed pond systems tests were performed using second season animals previously overwintered in a heated raceway. The shrimp, originally stocked as postlarvae, were reared to 150.0 mm in length and 30.0 g in weight. The shrimp were then harvested, overwintered, then returned to a 0.1 ha pond in Corpus Christi, Texas. In their second season the shrimp grew to 190.0 mm and 52.0 g and exhibited signs of sexual maturity. Sampling of the pond produced mated females that were removed from the pond and spawned in the laboratory.