Dong Liang

Competition among US ports to support larger container vessels is increasing needs for dredging in coastal ecosystems, which may conflict with provision of other ecosystem services. For example, the need to place materials dredged from approach channels in the Chesapeake Bay to the Port of Baltimore may compromise habitat quality for mature blue crab (Callinectes sapidus) during winter months. To assess the impacts of these important competing uses, we applied a common geostatistical approach, kriging, to estimate the abundance of blue crab in the Wolf Trap Approved Placement Site (WTAPS) and its northern extension (WTAPSNE). Data on crab abundance from an annual winter dredge survey for 1990–2020 was used to estimate both total adult and mature female abundances Baywide and for WTAPS and WTAPSNE to develop worst-case scenarios for the impact of dredged material placement. Total crab abundance in the placement sites was proportional to site area. However, mature female crabs were proportionally more abundant, indicating these placement sites are favored habitats. Analyses indicated that when Baywide female abundance was less than 150 million, the proportion of females in WTAPS was highly variable, and can be 2–3 times higher than would be predicted from area alone. When possible, dredged material placement activities in WTAPS and WTAPSNE should be limited to years when female age-1 abundance is above 150 million.

Objectives This study was conducted to examine urban–rural differences in the real-world prescribing pattern of oral anticoagulants and geographic variations in the prescribing pattern among clinicians serving Medicare beneficiaries in the USA. Design A cross-sectional study. Setting A real-world setting. Participants 232 665 clinicians who prescribed oral anticoagulants for Medicare beneficiaries from the 2020 Medicare Provider Utilisation and Payment Data were classified as warfarin only, direct oral anticoagulants (DOACs) only or warfarin+DOAC prescribers. Main outcome measures Urban–rural differences in the prescribing patterns were examined using multivariate multinominal logistic regression analysis. A geospatial analysis was conducted to estimate standardised prescriber ratios (SPR) for DOAC only or warfarin only prescribers versus warfarin+DOAC prescribers to illustrate hot and cold spots for DOAC adoption in the USA. Results 92% of clinicians who prescribed oral anticoagulants prescribed DOAC in 2020. Clinicians from rural regions were more likely to prescribe warfarin only (adjusted OR=1.335, 95% CI=(1.281 to 1.391)) and DOAC only (adjusted OR=2.052, 95% CI=(1.999 to 2.106)), compared with clinicians from urban regions. Hot spots for SPR of DOAC only versus warfarin+DOAC prescribers were mostly found in California, southern and southeastern states; cold spots were mostly found in Minnesota and Iowa. Hot spots for SPR of warfarin only versus warfarin+DOAC prescribers were mostly found in several metropolitan areas on the west coast and in Midwest; cold spots were mostly found on the east coast. Conclusions Urban–rural status of clinicians was associated with their prescribing patterns of oral anticoagulants. The study identifies geographical heterogeneity in DOAC adoption and highlights gaps that may need to be addressed for increased accessibility of DOAC for patients in need.

Technological advancement and the desire to better monitor shallow habitats in the Chesapeake Bay, Maryland, United States led to the initiation of several high-resolution monitoring programs such as ConMon (short for “Continuous Monitoring”) measuring oxygen, salinity, and chlorophyll-a at a 15-minute frequency. These monitoring efforts have yielded an enormous volume of data and insight into the condition of the tidal water of the Bay. But this information is underutilized in documenting the fine-scale variability of water quality, which is critical in identifying the link between water quality and ecological responses, partly due to the challenges in integrating monitoring data collected at different frequencies and locations. In a project to understand the environmental suitability of aquaculture sites and the future potential overlap between aquaculture and submerged aquatic vegetation, we developed a spatiotemporal synthesis of ConMon data with data from long-term, fixed-station seasonal monitoring. Here, we present our generalized additive model-based approach to predict salinity at high frequency (15 minutes) and fine spatial resolution (~100 meters) in the Maryland portion of the Bay, its major tributaries, and the shallow tidal creeks that exchange with the tributaries. Predictive performance was validated to be 1 PSU (practical salinity unit) in root mean square error using de novo monitoring. The resulting data provide insights into the environmental suitability of aquaculture, specifically the sensitivity of the Easter oyster (Crassostrea virginica) to low salinity stress. The spatiotemporal synthesis approach has potential applications for integrated monitoring and potential linkage with high-resolution water quality models for shallow habitats.

Technological advances in water quality measurement systems have provided the potential to expand high-frequency observations into coastal monitoring programs. However, with limited resources for monitoring budgets in natural waters that exhibit high temporal and spatial variability in water quality, there is a need to identify the locations and time periods where these new technologies can be deployed for maximum efficacy. To advance the capacity to make quantitative and objective decisions on the selection of monitoring locations and sampling frequency, we combined high-resolution numerical model simulations and multi-frequency water quality measurements to conduct a power analysis comparing alternative sampling designs in the assessment of water quality in the Chesapeake Bay. Specifically, we evaluated candidate monitoring networks that deployed both conventional long-term fixed station monitoring in deep channel areas and short-term continuous monitoring technologies in near-shore, shallow areas to assess 30-day dissolved oxygen criteria in two Bay tributaries. We conducted a cumulative frequency diagrams analysis to quantify the accuracy of each monitoring scheme in evaluating compliance with respect to the model. We used a Monte Carlo simulation to incorporate the spatial and temporal uncertainty of criteria failure. We found that additional long-term biweekly channel and short-term continuous shallow sampling efforts can lead to statistically unbiased and improved assessments at local spatial extents (less than 0.2 proportion of the assessed water body), especially when additional sampling is added at stations representing hypoxic water areas. Stations that represented seaward regions of the tributaries were more valuable in maintaining unbiased assessments of dissolved oxygen criteria attainment. This analysis highlights the importance of statistical evaluation of ongoing monitoring programs and suggests an approach to identify efficient deployments of monitoring resources and to improve assessment of other water quality metrics in estuarine ecosystems.

The Eastern Pacific leatherback turtle population ( Dermochelys coriacea ) has declined precipitously in recent years. One of the major causes is bycatch from coastal and pelagic fisheries. Fisheries observations are often underutilized, despite strong potential for this data to affect policy. In this study, we created a spatiotemporal species distribution model that synthesizes fisheries observations with remotely sensed environmental data. The model will be developed into a dynamic management tool for the Eastern Pacific leatherback population. We obtained leatherback observation data from multiple fisheries that have operated in the Southeast Pacific (2001–2018). A dynamic Poisson point process model was applied to predict leatherback intensity (observation per unit area) as a function of dynamic environmental covariates. This model serves as a tool for application by managers and stakeholders toward the reduction of leatherback turtle bycatch and provides a modeling framework for analyzing fisheries observations from other vulnerable populations and species.