Validation of a portable, waterproof blood pH analyser for elasmobranchs

Quantifying changes in blood chemistry in elasmobranchs can provide insights into the physiological insults caused by anthropogenic stress, and can ultimately inform conservation and management strategies. Current methods for analysing elasmobranch blood chemistry in the field are often costly and logistically challenging. We compared blood pH values measured using a portable, waterproof pH meter (Hanna Instruments HI 99161) with blood pH values measured by an i- STAT system (CG4+ cartridges), which was previously validated for teleost and elasmobranch fishes, to gauge the accuracy of the pH meter in determining whole blood pH for the Cuban dogfish (Squalus cubensis) and lemon shark (Negaprion brevirostris). There was a significant linear relationship between values derived via the pH meter and the i- STAT for both species across a wide range of pH values and temperatures (Cuban dogfish: 6.8-7.1 pH 24-30 degrees C; lemon sharks: 7.0-7.45 pH 25-31 degrees C). The relative error in the pH meter's measurements was similar to +/- 2.7%. Using this device with appropriate correction factors and consideration of calibration temperatures can result in both a rapid and accurate assessment of whole blood pH, at least for the two elasmobranch species examined here. Additional species should be examined in the future across a wide range of temperatures to determine whether correction factors are universal

Exercise intensity while hooked is associated with physiological status of longline-captured sharks

Some shark populations face declines owing to targeted capture and by-catch in longline fisheries. Exercise intensity during longline capture and physiological status may be associated, which could inform management strategies aimed at reducing the impacts of longline capture on sharks. The purpose of this study was to characterize relationships between exercise inten- sity and physiological status of longline-captured nurse sharks (Ginglymostoma cirratum) and Caribbean reef sharks (Carcharhinus perezi). Exercise intensity of longline-captured sharks was quantified with digital cameras and accelerometers, which was paired with blood-based physiological metrics from samples obtained immediately post-capture. Exercise intensity was associated with physiological status following longline capture. For nurse sharks, blood pH increased with capture dur- ation and the proportion of time exhibiting low-intensity exercise. Nurse sharks also had higher blood glucose and plasma potassium concentrations at higher sea surface temperatures. Associations between exercise intensity and physiological sta- tus for Caribbean reef sharks were equivocal; capture duration had a positive relation with blood lactate concentrations and a negative relationship with plasma chloride concentrations. Because Caribbean reef sharks did not appear able to influence blood pH through exercise intensity, this species was considered more vulnerable to physiological impairment. While both species appear quite resilient to longline capture, it remains to be determined if exercise intensity during capture is a useful tool for predicting mortality or tertiary sub-lethal consequences. Fisheries management should consider exercise during cap- ture for sharks when developing techniques to avoid by-catch or reduce physiological stress associated with capture

Conservation successes and challenges for wide-ranging sharks and rays

Overfishing is the most significant threat facing sharks and rays. Given the growth in consumption of seafood, combined with the compounding effects of habitat loss, climate change, and pollution, there is a need to identify recovery paths, particularly in poorly managed and poorly monitored fisheries. Here, we document conservation through fisheries management success for 11 coastal sharks in US waters by comparing population trends through a Bayesian state-space model before and after the implementation of the 1993 Fisheries Management Plan for Sharks. We took advantage of the spatial and temporal gradients in fishing exposure and fisheries management in the Western Atlantic to analyze the effect on the Red List status of all 26 wide-ranging coastal sharks and rays. We show that extinction risk was greater where fishing pressure was higher, but this was offset by the strength of management engagement (indicated by strength of National and Regional Plan of Action for sharks and rays). The regional Red List Index (which tracks changes in extinction risk through time) declined in all regions until the 1980s but then improved in the North and Central Atlantic such that the average extinction risk is currently half that in the Southwest. Many sharks and rays are wide ranging, and successful fisheries management in one country can be undone by poorly regulated or unregulated fishing elsewhere. Our study underscores that well-enforced, science-based management of carefully monitored fisheries can achieve conservation success, even for slow-growing species

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

The conservation implications of spatial and temporal variability in the diurnal use of Bahamian tidal mangrove creeks by transient predatory fishes

Mangrove creeks have a range of functional roles in tropical seascapes, but their use as feeding and refuge areas for commercially and ecologically important transient predators is poorly understood. This study used video cameras to investigate the diurnal use of three Bahamian mangrove creeks by transient predators during a 2-month period. More than 500 fishes from 10 species were recorded, including elasmobranchs, reef-associated fishes, and nearshore specialists. A multivariate analysis indicated that movement of the transient predator assemblage was not significantly linked to any abiotic variable and did not vary among creeks. Generalized linear mixed-effects models of the four most abundant transient predators demonstrated species-specific variations in creek use. Sightings of Caranx ruber and Negaprion brevirostris varied significantly among the three creeks. Furthermore, C. ruber was seen most frequently close to high tide, while N. brevirostris was seen more frequently with increasing time since sunrise and during higher tidal ranges. Sphyraena barracuda and Tylosurus crocodilus were seen most frequently just after low tide. All three creeks appear to be functionally important for transient predators, but these species exhibit considerable spatio-temporal variability in how they use this habitat. Mangrove creeks are threatened by a range of anthropogenic stressors, and are frequently a target of conservation initiatives. The species-specific spatial variability in creek use demonstrates that simply including representative creeks in marine protected areas could exclude functionally important areas. Furthermore, development that alters tidal cycles in creeks is likely to have significant impacts on transient predators, and underscores the need for restoration and conservation of hydrological flow

Perioperative Pain Management Practices Vary Across Time and Setting for Pediatric ACL Reconstruction: Trends From a National Database in the United States.

BackgroundSurgical and anesthetic techniques have enabled a shift to the ambulatory setting for the majority of patients with anterior cruciate ligament (ACL) tears. While this change likely reflects improvements in acute pain management, little is known about national trends in pediatric perioperative pain management after ACL reconstruction (ACLR).PurposeTo describe recent trends in the United States in perioperative pain management for pediatric ACLR.Study designCross-sectional study; Level of evidence, 3.MethodsPediatric patients (age, ≤18 years) who underwent ACLR with peripheral nerve blocks between January 2008 and December 2017 were identified in the Pediatric Health Information System database. We modeled the use of oral and intravenous analgesic medications over time using Bayesian logistic mixed models. Models were adjusted for patient age, sex, race, primary payer, and treatment setting (ambulatory, observation, or inpatient).ResultsThe study criteria produced a sample of 18,605 patients. Older children were more likely to receive intravenous acetaminophen, intravenous ketorolac, and oral and intravenous opioids. Younger children were more likely to receive ibuprofen. In our adjusted logistic model, treatment setting was found to be an independent predictor of the utilization of all medications. We found an increase in the overall utilization of oral acetaminophen (adjusted odds ratio [adj OR], 1.14 [95% CI, 1.04-1.23]), intravenous acetaminophen (adj OR, 1.42 [95% CI, 1.22-1.65]), and oral opioids (adj OR, 1.16 [95% CI, 1.06-1.28]) over the study period at a typical hospital. We found significant heterogeneity in medication use across hospitals, with the most heterogeneity in intravenous acetaminophen. Other studied descriptive variables did not appear to predict practices.ConclusionAfter adjusting for patient characteristics and treatment settings, pain management strategies varied among hospitals and over time. Patient age and treatment setting predicted practices. Regional anesthesia, opioid medications, and intravenous ketorolac remained the mainstays of treatment, while intravenous acetaminophen emerged in use over the course of the study period. The variability in the pain management of pediatric patients undergoing ACLR suggests that further study is necessary to establish the most effective means of perioperative pain management in these patients

Shark tooth collagen stable isotopes (δ\u3csup\u3e15\u3c/sup\u3eN and δ\u3csup\u3e13\u3c/sup\u3eC) as ecological proxies

The isotopic composition of tooth-bound collagen has long been used to reconstruct dietary patterns of animals in extant and palaeoecological systems. For sharks that replace teeth rapidly in a conveyor-like system, stable isotopes of tooth collagen (δ13CTeeth & δ15NTeeth) are poorly understood and lacking in ecological context relative to other non-lethally sampled tissues. This tissue holds promise, because shark jaws may preserve isotopic chronologies from which to infer individual-level ecological patterns across a range of temporal resolutions. Carbon and nitrogen stable isotope values were measured and compared between extracted tooth collagen and four other non-lethally sampled tissues of varying isotopic turnover rates: blood plasma, red blood cells, fin and muscle, from eight species of sharks. Individual-level isotopic variability of shark tooth collagen was evaluated by profiling teeth of different ages across whole jaws for the shortfin mako shark Isurus oxyrinchus and sandbar shark Carcharhinus plumbeus. Measurements of δ13CTeeth and δ15NTeeth were positively correlated with isotopic values from the four other tissues. Collagen δ13C was consistently 13C-enriched relative to all other tissues. Patterns for δ15N were slightly less uniform; tooth collagen was generally 15N-enriched relative to muscle and red blood cells, but congruent with fin and blood plasma (values clustered around a 1:1 relationship). Significant within-individual variability was observed across whole shortfin mako shark (δ13C range = 1.4‰, δ15N range = 3.6‰) and sandbar shark (δ13C range = 1.2‰–2.4‰, δ15N range = 1.7‰–2.4‰) jaws, which trended with tooth age. We conclude that amino acid composition and associated patterns of isotopic fractionation result in predictable isotopic offsets between tissues. Within-individual variability of tooth collagen stable isotope values suggests teeth of different ages may serve as ecological chronologies, that could be applied to studies on migration and individual-level diet variation across diverse time-scales. Greater understanding of tooth replacement rates, isotopic turnover and associated fractionation of tooth collagen will help refine potential ecological inferences, outlining clear goals for future scientific inquiry