7 research outputs found

    Seasonal Distribution and Abundance of Blue Crabs (Callinectes sapidus) in the Tampa Bay Estuary

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    Blue crabs (Callinectes sapidus (Rathbun)) are commercially important and are an integral part of the estuarine ecosystem as both predators and prey. Although adult blue crabs have been the focus of many studies, there is little published information on immature blue crab abundances, especially on the west Florida coast. The objectives of this study were to analyze the distributions and abundances of immature and adult blue crabs in the Tampa Bay estuary, specifically as they relate to 1) monthly and yearly trends in abundance and size, 2) timing of recruitment to the estuary, 3) sex- and size-determined distribution patterns, and 4) the influence of environmental factors, such as freshwater input. Catch rates, length frequencies, and indices of abundance were calculated for recruiting [≤20-mm carapace widths (CW)], juvenile (21–80-mm CW), and adult (\u3e80-mm CW) blue crabs caught during 1996 and 1997. Abundances of all size classes of blue crabs differed by region and month; juvenile and adult abundances were also significantly related to salinity. Immature crabs were collected in all months, confirming an extended spawning season, but there were elevated catches of recruiting blue crabs in February and September. Adults were caught year-round, with males generally being more abundant than females. Geographical regions close to the mouth of the bay had the highest densities of recruits, perhaps because of the supply of larvae being delivered to that area from offshore. With the use of monthly seine and river trawl data from an extended time period (1996–2004), annual variations in the abundance of immature and adult blue crabs were examined. A decline in the abundance of immature crabs collected in 21.3-m seines began after 1998, with a significant low occurring in 2002. A similar pattern was observed for adults collected in river trawls and by commercial fisheries. Unfavorable salinity regimes during this time period may have contributed to these abundance trends

    Seagrass Habitats as Nurseries for Reef-Associated Fish: Evidence from Fish Assemblages in and Adjacent to a Recently Established No-Take Marine Reserve in Dry Tortugas National Park, Florida, USA

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    Scientists and managers worldwide have increasingly advocated the use of marine protected areas (MPAs) to protect at—risk fish stocks. Most MPAs, however, have been established to protect reefs, while nonreef habitats, such as seagrasses, have received less consideration. In January 2007, an MPA called the Research Natural Area (RNA), was established as a no—take marine reserve in the Dry Tortugas National Park, Florida (DTNP), becoming the first MPA within the park boundaries to offer direct protection to seagrasses and reef habitat. We conducted a study using small—mesh Antillean Z—traps to (1) characterize fish assemblages in seagrass and reef habitats and (2) assess if differences in community structure existed between the RNA and adjacent open—use areas. Over 3 sampling events (Fall 2009, Spring 2010, Fall 2010), 3,163 individuals of 38 species were collected from 129 stations. Fish assemblages differed significantly among sampling events and between habitat types, but no differences were evident between the RNA and open—use areas. Unlike previous sampling efforts that focused on larger—bodied fish in the DTNP, Z—traps targeted small—bodied reef— and seagrass—associated fishes. Juvenile Haemulon plumierii and Epinephelus morio strongly contributed to community structure and were more abundant in seagrass habitats, which may serve as an important nursery area. Because the RNA was only established 2 years before this study was conducted, it could still be several years before benefits to the juvenile population become evident, but this study establishes the importance of consider-ing seagrass habitats when developing a reef—associated no—take marine reserve

    Spatial and Size Distribution of Red Drum Caught and Released in Tampa Bay, Florida, and Factors Associated with Post-Release Hooking Mortality

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    The recreational fishery for red drum (Sciaenops ocellatus) in Florida is unusual in that most red drum targeted are immature and caught within estuarine waters. Current state regulations rely exclusively on bag and size limits, resulting in the release of a large proportion of captured individuals. This study employed hook-and-line sampling conducted monthly in Tampa Bay, Florida and catch-and-release mortality experiments to determine the spatial and size distribution of red drum and the mortality rate of released fish, respectively. Of the 1,405 red drum collected, more than 70% were smaller than the minimum legal size (457 mm standard length (SL)). Size structure of red drum varied spatially and reflected ontogenetic patterns of habitat use. Data collected during catch-and-release mortality experiments were analyzed to identify factors associated with mortality. A total of 251 red drum (203-618 mm SL) were caught and held for 48 h during 9 experiments, with an overall mortality rate of 5.6%. Higher water temperature and anatomical hook position were significantly correlated with mortality; lip-hooked fish had the lowest mortality rate, while throat-hooked fish had the highest. Although hook type was not correlated with mortality, it did influence whether a fish was deep-hooked. Fish caught by J-hooks were more likely to be deep-hooked than those caught by circle hooks. Catch-and-release fishing is an effective management tool for reducing take but may contribute to short-term mortality, especially in warm, subtropical estuaries

    Thigh-length compression stockings and DVT after stroke

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    Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease

    Azithromycin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Background Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatory actions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19. Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospital with COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients were randomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once per day by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatment groups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment and were twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants and local study staff were not masked to the allocated treatment, but all others involved in the trial were masked to the outcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) were eligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was 65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomly allocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall, 561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days (rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median 10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days (rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, no significant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilation or death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24). Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or other prespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restricted to patients in whom there is a clear antimicrobial indication. Funding UK Research and Innovation (Medical Research Council) and National Institute of Health Research
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