Epiplastral and geographic variation in Echmatemys, a geoemydid turtle from the Eocene of North America: A multi-tiered analysis of epiplastral shape complexity

Numerous geoemydid turtle fossils from the extinct genus Echmatemys have been recovered from the middle Eocene Uinta Formation, Uinta Basin, Utah over the past several decades. Here, we tested whether co-occurring Uintan species Echmatemys callopyge and E. uintensis can be reliably differentiated based on epiplastral morphology, and whether their geospatial distributions overlapped significantly. The geographic spatial and stratigraphic distributions of Uinta Basin E. callopyge and E. uintensis specimens were compared using ArcGIS and analysis of variance (ANOVA). The analysis revealed overlapping geographic distributions of these two species, and no significant differences in stratigraphic dispersal. This finding of extensive geospatial overlap between the two Uintan Echmatemys species highlights the need for accurate taxonomic identification, such as the gular scale morphology validated here. In addition, we sought to address a methodological question regarding the relative efficacy of data complexity in this context. Using epiplastra from three additional Eocene species of Echmatemys, we employed hierarchical analyses of increasing data complexity, from standard linear dimensions to 2D geometric morphometrics to 3D laser scans, to determine the degree to which data complexity contributes to taxonomic assessments within this genus. Uintan species E. callopyge and E. uintensis were found to differ significantly in epiplastral shape as captured by all three categories of data. These findings verify that these two co-occurring species can be differentiated consistently using the shape of the gular scale, and that the use of geometric morphometrics can improve identification of fragmentary specimens. Among the non-Uintan species, dorsal and ventral 2D landmark data reliably differentiated among species, but the linear dimensions were less useful

Patterns in island endemic forest-dependent bird research: the Caribbean as a case-study

From Springer Nature via Jisc Publications RouterHistory: received 2018-10-25, rev-recd 2019-03-19, registration 2019-04-26, accepted 2019-04-26, online 2019-05-04, epub 2019-05-04, ppub 2019-06Publication status: PublishedAbstract: Unequal patterns in research effort can result in inaccurate assessments of species extinction risk or ineffective management. A group of notable conservation concern are tropical island endemic birds, many of which are also forest-dependent, which increases their vulnerability to extinction. Yet, island bird species have received limited research attention compared to their continental congeners, despite this taxon being globally regarded as well-studied. We used the insular Caribbean, a globally important endemism hotspot with high rates of deforestation, to explore research bias of island and regional endemic forest-dependent birds. A review of the published literature (n = 992) found no significant increase in the number of studies over the search period. Research effort was significantly higher among species with threatened status, long generation time, wide habitat breadth and low to intermediate elevational distributions. Among family groups, the Psittacidae received the highest research effort, while the Cuculidae were the most underrepresented family (30-fold higher and six-fold less than expected, respectively). We found geographic biases in effort, with Jamaica having six-fold less and Puerto Rico eight times more research than expected for their level of endemism. These patterns likely reflect individual interests and limited capacity and funding, typical of Small Island Developing States. With over 50% of species in this review having declining population trends, we recommend prioritizing research that emphasises conservation- and management-relevant data across underrepresented families and islands, by fostering greater collaboration between researchers, practitioners and the existing local amateur ornithological community

Simulated climate change impacts on striped bass, blue crab and Eastern oyster in oyster sanctuary habitats of Chesapeake Bay

Oyster reefs and the species that inhabit them will likely be impacted by shifts in environmental conditions due to climate change. This study examined the potential impact of long-term shifts in water temperature and salinity as a result of climate change on the biomasses of important fisheries species within oyster sanctuary sites in the Choptank and Little Choptank river complex (CLC) in Chesapeake Bay using an Ecopath with Ecosim food web model. The model was used to evaluate changes in the oyster reef food web, with particular emphasis on impacts to striped bass (Morone saxatilis), blue crab (Callinectes sapidus), and Eastern oysters (Crassostrea virginica). Eight different climate change scenarios were used to vary water temperature and salinity within Chesapeake Bay up to the year 2100 based on projections given by previous studies. Simulations used a 4 °C increase in temperature along with an increase (+12 or +10) or decrease (−2) in salinity at annual time steps. The rate of change in species biomasses across scenarios ranged from −0.0052 to 0.0008 t/km2/month for striped bass, −0.0021 to 0.0026 t/km2/month for blue crab and −0.0018 to 0.0026 t/km2/month for oysters. Across the majority of scenarios, the biomasses of striped bass and blue crab decreased, while oyster biomass increased. These results begin to offer insight on the interaction between oyster reef restoration benefits and climate change. The modeling framework utilized by this study may be adapted to other systems to assess the effects of climate change on other coastal restoration habitats

Measuring the Value of Forage Fish to Recreational Fishermen

Fisheries management has been traditionally single-species oriented. Only recently more pressure has been put on developing a holistic, science-based approach that considers the ecosystem as a whole. This approach is widely known as ecosystem-based fisheries management (EBFM). One of the most often highlighted aspects of EBFM is the relevance of predator-prey interactions in the aquatic ecosystems. The motivation is that there are considerable trade-offs between the supporting role of forage species as energy conveyors in food webs and provisioning service as target species to fisheries. We study this aspect by looking at the Chesapeake Bay. The motivation is a recent debate on the potential impact of excessive forage base fishing. In particular, we are interested in the propagation of forage overfishing through the food web and its influence on more valuable, higher trophic species fisheries. We develop a Bayesian model of recreational harvest of striped bass where benefits are derived from stock size as well as age structure. The age structure drives the probability of catching a fish of a particular size what is of considerable importance to the fishery highly constrained by minimum catch size regulations. Then, using a dynamic multispecies framework (Ecosim) and modified random utility model, we analyze multiple scenarios varying by menhaden regulations and derive benefits changes imposed on the striped bass recreational fishery. We focus on the recreational sector as recent research indicates that the recreational fishing is becoming increasingly important and new management strategies may be necessary to address this shifting trend

Dynamic modelling of flexibly supported gears using iterative convergence of tooth mesh stiffness

This paper presents a new gear dynamic model for flexibly supported gear sets aiming to improve the accuracy of gear fault diagnostic methods. In the model, the operating gear centre distance, which can affect the gear design parameters, like the gear mesh stiffness, has been selected as the iteration criteria because it will significantly deviate from its nominal value for a flexible supported gearset when it is operating. The FEA method was developed for calculation of the gear mesh stiffnesses with varying gear centre distance, which can then be incorporated by iteration into the gear dynamic model. The dynamic simulation results from previous models that neglect the operating gear centre distance change and those from the new model that incorporate the operating gear centre distance change were obtained by numerical integration of the differential equations of motion using the Newmark method. Some common diagnostic tools were utilized to investigate the difference and comparison of the fault diagnostic results between the two models. The results of this paper indicate that the major difference between the two diagnostic results for the cracked tooth exists in the extended duration of the crack event and in changes to the phase modulation of the coherent time synchronous averaged signal even though other notable differences from other diagnostic results can also be observed

Network approaches for formalizing conceptual models in ecosystem-based management

Funding Intermodel comparisons were supported through funding from the NOAA Integrated Ecosystem Assessment Program. P.S. McDonald’s involvement was funded in part by a grant from Washington Sea Grant, University of Washington, pursuant to National Oceanic and Atmospheric Administration Award number NA14OAR4170078. Funding for RPW was supported by the National Marine Fisheries Service (NMFS)/Sea Grant Population and Ecosystem Dynamics Graduate Fellowship via federal award NA14OAR4170077. Acknowledgements We would like to acknowledge and thank the participants of the NOAA Integrated Ecosystem Assessment Program conceptual network modelling workshop at Baton Rouge, LA in July 2018. The discussions at this meeting formed some of the basis for the ideas presented in this manuscript. We also thank J. Moss and two anonymous reviewers for valuable comments on earlier manuscript drafts. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the National Marine Fisheries Service, NOAA. Reference to trade names does not imply endorsement by the National Marine Fisheries Service, NOAA. This is NOAA Integrated Ecosystem Assessment Program contribution number 2021_3.Peer reviewedPostprin

Combining Ecosystem and Single-Species Modeling to Provide Ecosystem-Based Fisheries Management Advice Within Current Management Systems.

Although many countries have formally committed to Ecosystem-Based Fisheries Management (EBFM), actual progress toward these goals has been slow. This paper presents two independent case studies that have combined strategic advice from ecosystem modeling with the tactical advice of single-species assessment models to provide practical ecosystem-based management advice. With this approach, stock status, reference points, and initial target F are computed from a single-species model, then an ecosystem model rescales the target F according to ecosystem indicators without crossing pre-calculated single-species precautionary limits. Finally, the single-species model computes the quota advice from the rescaled target F, termed here Feco. Such a methodology incorporates both the detailed population reconstructions of the single-species model and the broader ecosystem perspective from ecosystem-based modeling, and fits into existing management schemes. The advocated method has arisen from independent work on EBFM in two international fisheries management systems: (1) Atlantic menhaden in the United States and (2) the multi species fisheries of the Irish Sea, in the Celtic Seas ecoregion. In the Atlantic menhaden example, the objective was to develop ecological reference points (ERPs) that account for the effect of menhaden harvest on predator populations and the tradeoffs associated with forage fish management. In the Irish Sea, the objective was to account for ecosystem variability when setting quotas for the individual target species. These two exercises were aimed at different management needs, but both arrived at a process of adjusting the target F used within the current single-species management. Although the approach has limitations, it represents a practical step toward EBFM, which can be adapted to a range of ecosystem objectives and applied within current management systems.publishedVersio

It is Not All About the Benjamins: Understanding Preferences for Mates with Resources

We contend that preferences for mates with resources or money might be calibrated on where a potential mate gets her/his money. In three studies (N= 668) we examined the nature of individuals' preferences for mates who have resources or money. Both sexes preferred a long-term mate who has earned her/his money over other sources. In particular, women preferred mates who earned their money over other potential means of getting resources (i.e., inheritance, embezzlement, and windfall). Women maintained a high level of interest in mates who earned their money regardless of duration of the mateship whereas men became less interested in a mate who earned her money in the context of short-term relationships. Overall, the sexes preferred a mate who earned their money more strongly in the long-term than the short-term context. Results are discussed from evolutionary and sociocultural models of mate preferences

Demonstration of strain-specific CD8 T cell responses to Theileria annulata

The present study set out to examine the nature and specificity of the bovine CD8 T cell response at the clonal level in a group of eight animals immunized with a cloned population of Theileria annulata. The results demonstrated that immunized animals generated parasite-specific CD8 T cells that produced IFNγ in response to parasite stimulation but had highly variable levels of cytotoxicity for parasitized cells. The study also demonstrated that these parasite-specific CD8 T cells could be propagated and cloned in vitro from the memory T cell pool of cattle immunized with live T. annulata parasites. Within the small group of animals studied, there was evidence that responses were preferentially directed to antigens presented by an A10+ class I major histocompatibility complex (MHC) haplotype, suggesting that responses restricted by products of this haplotype may be dominant. The A10-restricted responses showed differential recognition of different parasite isolates and clones. By using a cloned population of parasites both for immunization of the animals and for in vitro analyses of the responses, we obtained unambiguous evidence that at least a proportion of CD8 T cells restricted by one MHC haplotype were parasite strain restricted