scholarly journals The impacts of warming and hypoxia on the performance of an obligate ram ventilator

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel P Crear ◽  
Rich W Brill ◽  
Peter G Bushnell ◽  
Robert J Latour ◽  
Gail D Schwieterman ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Individual Species ◽  
Nursery Ground ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Western Atlantic ◽  
Nursery Habitats ◽  
Hypoxic Water ◽  
Overall Performance ◽  
Metabolic Performance

Abstract Climate change is causing the warming and deoxygenation of coastal habitats like Chesapeake Bay that serve as important nursery habitats for many marine fish species. As conditions continue to change, it is important to understand how these changes impact individual species’ behavioral and metabolic performance. The sandbar shark (Carcharhinus plumbeus) is an obligate ram-ventilating apex predator whose juveniles use Chesapeake Bay as a nursery ground up to 10 years of age. The objective of this study was to measure juvenile sandbar shark metabolic and behavioral performance as a proxy for overall performance (i.e. fitness or success) when exposed to warm and hypoxic water. Juvenile sandbar sharks (79.5–113.5 cm total length) were collected from an estuary along the eastern shore of Virginia and returned to lab where they were fitted with an accelerometer, placed in a respirometer and exposed to varying temperatures and oxygen levels. Juvenile sandbar shark overall performance declined substantially at 32°C or when dissolved oxygen concentration was reduced below 3.5 mg l−1 (51% oxygen saturation between 24–32°C). As the extent of warm hypoxic water increases in Chesapeake Bay, we expect that the available sandbar shark nursery habitat will be reduced, which may negatively impact the population of sandbar sharks in the western Atlantic as well as the overall health of the ecosystem within Chesapeake Bay.

scholarly journals Sensitivity of a shark nursery habitat to a changing climate

2020 ◽  
Vol 652 ◽  
pp. 123-136
Author(s):  
DP Crear ◽  
RJ Latour ◽  
MAM Friedrichs ◽  
P St-Laurent ◽  
KC Weng
Keyword(s):  
Climate Change ◽  
Chesapeake Bay ◽  
Foraging Ecology ◽  
Life Stage ◽  
Nursery Habitat ◽  
Habitat Model ◽  
Suitable Habitat ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Nursery Habitats

Nursery area habitats such as estuaries are vital for the success of many fish populations. Climate change is altering conditions in these areas, which can thus impact the availability of suitable nursery habitat. The sandbar shark Carcharhinus plumbeus uses Chesapeake Bay (USA) as a nursery habitat during the summer months from birth up to 10 yr of age. To assess the impacts of climate change on juvenile sandbar sharks, we developed a habitat model using longline data collected from a fishery-independent survey within Chesapeake Bay. With this model, we projected contemporary and future distributions of suitable habitat for juvenile sandbar sharks in Chesapeake Bay under varying environmental regimes. Predicted suitable juvenile sandbar shark habitat was negatively impacted by future increases in temperature, but positively influenced by future decreases in dissolved oxygen. The latter trend was likely related to the habitat partitioning that occurs between different life stages. Changes in salinity had relatively small impacts. By end-of-century the projected amount of suitable bottom habitat decreased; however, when incorporating the entire water column, projected suitable habitat increased. This suggests that juvenile sandbar sharks may need to make a behavioral shift to avoid non-preferred conditions, which could alter their foraging ecology or refuge strategies. As nursery habitats change with climate change, it is crucial to understand how a species may be impacted during this vital life stage when trying to predict overall species success in the future.

Effective size closely approximates the census size in the heavily exploited western Atlantic population of the sandbar shark, Carcharhinus plumbeus

2008 ◽  
Vol 10 (6) ◽  
pp. 1697-1705 ◽  
Author(s):  
David S. Portnoy ◽  
Jan R. McDowell ◽  
Camilla T. McCandless ◽  
John A. Musick ◽  
John E. Graves
Keyword(s):  
Effective Size ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Western Atlantic ◽  
Atlantic Population ◽  
Census Size

scholarly journals Using historical and citizen science data to improve knowledge about the occurrence of the elusive sandbar shark Carcharhinus plumbeus (Chondrichthyes – Carcharhinidae) in the Adriatic Sea

2021 ◽  
Vol 22 (1) ◽  
pp. 169
Author(s):  
PATRICK L. JAMBURA ◽  
ILIJA ĆETKOVIĆ ◽  
JÜRGEN KRIWET ◽  
JULIA TÜRTSCHER
Keyword(s):  
Citizen Science ◽  
Threatened Species ◽  
Adriatic Sea ◽  
Nursery Ground ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
High Concentration ◽  
Science Data ◽  
Po River ◽  
The Mediterranean

The Mediterranean Sea is an extinction hotspot for sharks, skates, and rays, with at least half of all species being threatened. The sandbar shark Carcharhinus plumbeus is among the most threatened species and is declared endangered (EN) in the Mediterranean according to the IUCN Red List of Threatened Species. The Adriatic Sea was previously proposed to be an important nursery area for this species based on sporadic sightings of neonates and juveniles. However, this species is generally considered to be rare in this region, and reports of its presence are scarce. Here, we present new records for the sandbar shark in the Adriatic Sea and review spatial and temporal data accumulated from literature, museum specimens, and citizen science initiatives in an attempt to assess the distribution and seasonality of this species. The majority of the records were from neonate and juvenile sandbar sharks, and three hotspots for their occurrence could be identified: (1) the Emilia-Romagna region, (2) the Veneto region, and (3) the Gulf of Trieste. Our data indicate a high concentration of sandbar sharks around the delta of the Po river, emphasising the need for scientific surveys in this confined area in order to confirm a possible nursery ground. Data collected by citizen science initiatives reveal that this species is still present in the Adriatic Sea and might be more abundant than previously thought, underlining the potential of citizen science as a valuable tool to monitor the distribution of rare and endangered species.

World phylogeography and male-mediated gene flow in the sandbar shark, Carcharhinus plumbeus

2010 ◽  
Vol 19 (10) ◽  
pp. 1994-2010 ◽  
Author(s):  
DAVID S. PORTNOY ◽  
JAN R. MCDOWELL ◽  
EDWARD J. HEIST ◽  
JOHN A. MUSICK ◽  
JOHN E. GRAVES
Keyword(s):  
Gene Flow ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus

Multicenter clinical evaluation of VITEK® 2 meropenem-vaborbactam for susceptibility testing of Enterobacterales and Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Hari P. Dwivedi ◽  
Simone Franklin ◽  
Sukantha Chandrasekaran ◽  
Omai Garner ◽  
Maria M. Traczewski ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Automated System ◽  
Individual Species ◽  
Method Performance ◽  
Overall Performance ◽  
Vitek 2 ◽  
Tract Infections ◽  
Alternate Solution ◽  
After Error

The carbapenem/beta-lactamase inhibitor (meropenem-vaborbactam; MEV) used to treat complicated urinary tract infections and pyelonephritis in adults was approved in 2017 by the U.S. Food and Drug Administration (FDA). We evaluated VITEK 2 MEV (bioMérieux, Durham, NC) compared to the reference broth microdilution (BMD) method. Of 449 Enterobacterales isolates analyzed per FDA/CLSI breakpoints, overall performance was 98.2% Essential Agreement (EA), 98.7% Category Agreement (CA), and 0% Very Major Errors (VME) or Major Errors (ME). For FDA intended for use 438 Enterobacterales isolates, performance was 98.2% EA, 98.6% CA, and 0% VME or ME. Evaluable EA was 81.0% but with only 42 on-scale evaluable results. Individual species demonstrated EA and CA rates ≥ 90% without any VME or ME. When evaluated using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, overall VITEK 2 MEV performance for Enterobacterales and Pseudomonas aeruginosa demonstrated 97.3% EA, 99.2% CA, 2.3% VME, and 0.6% ME (after error resolution: 97.3% EA, 99.4% CA, 2.2% VME, and 0.4% ME) compared to the reference BMD method. Performance for P. aeruginosa included 92.2% EA, 97.4% CA, 0% VME, and 3.0% ME (after error resolution: 92.2% EA, 98.7% CA, 0% VME, and 1.5% ME). Performance for Enterobacterales included 98.2% EA, 99.6% CA, 3.0% VME, and 0.2% ME. Evaluable EA was 80.6% but due to only 67 evaluable results. These findings support VITEK 2 MEV as an accurate automated system for MEV susceptibility testing of Enterobacterales and P. aeruginosa and could be an alternate solution to the manual labor intensive reference BMD method.

Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

1999 ◽  
Keyword(s):  
Simulation Model ◽  
Maximum Size ◽  
Population Projections ◽  
Population Declines ◽  
Sandbar Shark ◽  
Carcharhinus Plumbeus ◽  
Marine Animals ◽  
Important Species ◽  
Age Structured ◽  
Stage Class

<em>Abstract.</em> —The sandbar shark <em>Carcharhinus plumbeus </em> is the most important species caught in the commercial shark fishery operating off the U.S. Atlantic and Gulf of Mexico coasts. Previous demographic studies of this and other species of sharks have utilized age-structured, deterministic life tables that provided point estimates of maximum rates of increase. To reduce some of the uncertainty in estimates of age at maturity and longevity—especially acute in the case of the sandbar shark—I constructed a stage-based model based on an Usher matrix that utilizes the more reliable estimates of size at maturity and maximum size for this species in the northwest Atlantic. Because demographic variability also can affect estimated rates of increase, I introduced stochasticity into the model by randomly selecting fecundity rates from an empirically determined distribution, and natural mortality rates from estimates obtained through four life history methods. The simulation model was applied to females only. Population projections 20 years forward in time without exploitation predicted slowly growing populations at approximately 1.3%/year. Application of a constant instantaneous mortality rate (<EM>F</EM> ) of 0.1 to each stage-class separately indicated that removal of large juveniles would produce the greatest population declines, whereas removal of age-0 individuals would be sustainable. The simulation model was then used to predict potential outcomes under three hypothetical harvesting scenarios using the current U.S. commercial quota indicating that all strategies produced pronounced population declines.

What ecological role do soft-substrate tide pools play for fishes? Difference in community structures between estuarine and coastal tidal flats in subtropical Japan

2020 ◽  
Vol 71 (7) ◽  
pp. 737
Author(s):  
Taiga Kunishima ◽  
Katsunori Tachihara
Keyword(s):  
Tidal Flat ◽  
High Tide ◽  
Tidal Flats ◽  
Individual Species ◽  
Nursery Ground ◽  
Ecological Role ◽  
Soft Substrate ◽  
Use Patterns ◽  
Habitat Value ◽  
Ecological Roles

Soft-substrate tide pools are considered important habitats for fishes from an ecological perspective. However, the ecological roles of such pools and use patterns by fish remain unclear, especially regarding differences between estuarine and coastal tidal flats. In this study, quantitative sampling using the quadrat method was performed in the estuarine and coastal tidal flats on Okinawa-jima Island of subtropical Japan during four seasons. Ecological roles of soft-substrate tide pools were classified as follows: (1) permanent habitat for residents; (2) nursery ground for transients; and (3) waiting area until high tide for accidental species. Within these classifications, the ecological role and value of tide pools for transient fishes varied between the tidal flat types. The habitat value of tide pools is higher for residents than for transient species because the habitat is not replaceable for residents because of their specific ability to survive there. By contrast, transient and accidental species use the tide pools as temporary habitats; however, their high diversity affects the variation in community structure on Okinawa-jima Island. Our results suggest that we should consider not only species diversity, but also habitat use patterns of individual species, together with their life history, when evaluating habitat value with regard to conservation and management of each tidal flat.

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