Egress of Adult Sport Fish from an Estuarine Reserve within Merritt Island National Wildlife Refuge, Florida

A tag-recapture study was conducted within Merritt Island National Wildlife Refuge in the waters surrounding Kennedy Space Center, Florida (where public access has been restricted since 1962), to document egress of adult sport fish from an estuarine reserve. A total of 3,358 sport fish were tagged within the restricted areas. The species tagged were red drum Sciaenops ocellatus (n = 1,366), spotted seatrout Cynoscion nebulosus (n = 927), black drum Pogonias cromis (n = 760), and common snook Centropomis undecimalis (n = 305). Results showed that adult sport fish moved from the restricted areas within Merritt Island National Wildlife Refuge to surrounding areas open to fishing. The recapture rates, based on angler responses outside of the restricted areas, were 3.1%, 0.8%, 2.9%, and 16.1% for red drum, spotted seatrout, black drum, and common snook, respectively. In general, red drum, spotted seatrout, and black drum were recaptured in waters adjacent to the restricted areas. Common snook, however, migrated from the restricted areas south to inlets. Tag recaptures for red drum, spotted seatrout, and black drum, together with a previous study that found greater abundance and size of sport fish in the restricted areas than in adjacent areas open to fishing, substantiate the fish replenishment zone function of the restricted areas. The restricted areas within Merritt Island National Wildlife Refuge protect fish populations and large adult sport fish egress to surrounding waters open to fishing

Ecological Studies of Wolves on Isle Royale, 1979-1980

Annual Report 1979-1980 (Covering the twenty-second year of research)https://digitalcommons.mtu.edu/wolf-annualreports/1041/thumbnail.jp

Temperature Variability in a Subtropical Estuary and Implications for Common Snook Centropomus undecimalis, a Cold-Sensitive Fish

Variability in winter water temperature was compared among three habitat types (estuary, river, canal) in a subtropical estuarine system to explore how it might affect site selection and survival of a cold-sensitive fish, Common Snook Centropomus undecimalis. The study was conducted during three winters (2008–2010); a rapid cooling event occurred during the first winter, mild temperatures the second, and an extreme cold event in the third (an 80-yr event). During the extreme cold event in January 2010, catastrophic fish mortality occurred throughout the region that resulted in the emergency closure of the Common Snook recreational fishery. Over the entire studied estuarine system, dead Common Snook were reported at 43 sites; 26 of the sites were large fish kills consisting of 100–2,000 individuals. The distribution of mortality sites was widespread, although most were located in the estuary proper (n = 39), with only several in rivers and canals (n = 4). Temperature loggers recorded similar water temperatures among habitat types (estuary, river, canal), except during short periods (~3 d; up to 2°C) after cold fronts; this indicates that fish have distinct time constraints if searching for warmer water sites. During the short periods after cold fronts, canal water temperatures were the warmest and most stable, whereas the river and estuary temperature rankings varied

Ecological Studies of Wolves on Isle Royale, 1980-1981

Annual Report 1980-1981 (Covering the twenty-third year of research)https://digitalcommons.mtu.edu/wolf-annualreports/1040/thumbnail.jp

Patterns of fish use and piscivore abundance within a reconnected saltmarsh impoundment in the northern Indian River Lagoon, Florida

Nearly all saltmarshes in east-central, Florida were impounded for mosquito control during the 1960s. The majority of these marshes have since been reconnected to the estuary by culverts, providing an opportunity to effectively measure exchange of aquatic organisms. A multi-gear approach was used monthly to simultaneously estimate fish standing stock (cast net), fish exchange with the estuary (culvert traps), and piscivore abundance (gill nets and bird counts) to document patterns of fish use in a reconnected saltmarsh impoundment. Changes in saltmarsh fish abundance, and exchange of fish with the estuary reflected the seasonal pattern of marsh flooding in the northern Indian River Lagoon system. During a 6-month period of marsh flooding, resident fish had continuous access to the marsh surface. Large piscivorous fish regularly entered the impoundment via creeks and ditches to prey upon small resident fish, and piscivorous birds aggregated following major fish movements to the marsh surface or to deep habitats. As water levels receded in winter, saltmarsh fish concentrated into deep habitats and emigration to the estuary ensued (200% greater biomass left the impoundment than entered). Fish abundance and community structure along the estuary shoreline (although fringed with marsh vegetation) were not analogous to marsh creeks and ditches. Perimeter ditches provided deep-water habitat for large estuarine predators, and shallow creeks served as an alternative habitat for resident fish when the marsh surface was dry. Use of the impoundment as nursery by transients was limited to Mugil cephalus Linnaeus, but large juvenile and adult piscivorous fish used the impoundment for feeding. In conclusion, the saltmarsh impoundment was a feeding site for piscivorous fish and birds, and functioned as a net exporter of forage fish to adjacent estuarine waters

Feeding Habits of Common Snook, Centropomus undecimalis, in Charlotte Harbor, Florida

We examined the feeding habits, ontogenetic and seasonal diet variations, and predator size–prey size relationships of common snook, Centropomus undecimalis, in Charlotte Harbor, Florida, through stomach contents analysis. A total of 694 stomachs were extracted from common snook (300–882 mm standard length [SL]) during a 24-month period (March 2000–February 2002); 432 stomachs contained prey items. At least 37 prey taxa were identified, including 19 that had not been previously reported. Fishes made up 71% of the prey by number and 90% by weight. Three prey items made up almost 50% of the diet numerically—Lagodon rhomboides, Anchoa spp., and Farfantepenaeus duorarum. Seven species made up more than 60% of the diet by weight—L. rhomboides, Cynoscion nebulosus, Mugil gyrans, Bairdiella chrysoura, Synodus foetens, Orthopristis chrysoptera, and Mugil cephalus. An ontogenetic shift in prey preference was identified in adult common snook at around 550 mm SL. Smaller individuals (300–549 mm SL) ate more F. duorarum, palaemonid shrimp, cyprinodontids, and Eucinostomus spp. than did larger individuals (550–882 mm SL), which ate more S. foetens, ariids, and sciaenids. Significant, positive relationships between predator size and prey size were observed between common snook and L. rhomboides, O. chrysoptera, portunid crabs, and all fish prey combined. Prey size selection contributed to some seasonal differences in their diet. For example, in winter when L. rhomboides are abundant in the estuary and small in size (mean = 23 mm SL), common snook ate few individuals, but they consumed many during summer when larger L. rhomboides (mean = 51 mm SL) were available. In summary, common snook are opportunistic predators that feed on a wide variety of prey and exploit specific-sized prey that are abundant in their environment

Ecological Studies of Wolves on Isle Royale, 1981-1982

Annual Report 1981-1982 (Covering the twenty-fourth year of research)https://digitalcommons.mtu.edu/wolf-annualreports/1039/thumbnail.jp

Habitat Use by Juvenile Gag, Mycteroperca microlepis (Pisces: Serranidae), in Subtropical Charlotte Harbor, Florida (USA)

Estuaries play a key role in the juvenile stage of gag (Myeteroperca microlepis). The use of estuarine habitats by juvenlle gag has been examined in temperate estuaries, which are at the northern limits of the range of this species, but the importance of subtropical estuaries during the early life history of this species has not been studied extensively. Gag were collected in subtropical Charlotte Harbor, Florida, during routine monthiy sampling from January 1996 to Decemher 2002. Juvenlle gag were collected using a 21.3-m seine, a 183-m haul seine, and a 183-m purse seine. A total of 738 individuals ranging from 30 to 489 mm standard length (SL) were collected in 4,480 samples. Most gag (96%) were probably young-of-the-year (\u3c 288 mm SL). The majority of juveniles were collected in polyhaline Gasparilla and Pine Island sounds from April to December, with a few larger individuals captured year-round. The observed period of gag settlement was similar to thet reported in other subtropical and temperate estuaries, but gag in Charlotte Harbor remained in the estuary longer and egressed at a larger size than did gag in other estuaries. Relative abundance of juvenile gag within Charlotte Harbor was greatest on shallow seagrass shoals but was also high along flinging mangrove shorelines, which is a habitat not previously reported for gag

Long-term site fidelity of endangered smalltooth sawfish (Pristis pectinata) from different mothers

Understanding how endangered species use nursery habitats is vital for recovery planning. Research on the smalltooth sawfish (Pristis pectinata) has shown that areas of estuarine nurseries, called hotspots, are used consistently. The objectives of our study were 1) to determine whether 10 young-of-the-year smalltooth sawfish in an artificial, non-main-stem portion (i.e., a seawall canal system) of a hotspot were descended from one or different mothers and 2) to document long-term habitat use by these individuals. At least 4 mothers contributed to the group, which comprised siblings, half-siblings, and unrelated individuals. Young sawfish exhibited site fidelity to their capture location, spending 61% of their time there. Continuous residency lasted as long as 86 days, but these fish made small-scale diel

The STOP COVID 2 study: Fluvoxamine vs placebo for outpatients with symptomatic COVID-19, a fully remote randomized controlled trial

BACKGROUND: Prior randomized clinical trials have reported benefit of fluvoxamine ≥200 mg/d vs placebo for patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: This randomized, double-blind, placebo-controlled, fully remote multisite clinical trial evaluated whether fluvoxamine prevents clinical deterioration in higher-risk outpatients with acute coronavirus disease 2019 (COVID-19). Between December 2020 and May 2021, nonhospitalized US and Canadian participants with confirmed symptomatic infection received fluvoxamine (50 mg on day 1, 100 mg twice daily thereafter) or placebo for 15 days. The primary modified intent-to-treat (mITT) population included participants who started the intervention within 7 days of symptom onset with a baseline oxygen saturation ≥92%. The primary outcome was clinical deterioration within 15 days of randomization, defined as having both (1) shortness of breath (severity ≥4 on a 0-10 scale or requiring hospitalization) RESULTS: A total of 547 participants were randomized and met mITT criteria (n = 272 fluvoxamine, n = 275 placebo). The Data Safety Monitoring Board recommended stopping early for futility related to lower-than-predicted event rates and declining accrual concurrent with vaccine availability in the United States and Canada. Clinical deterioration occurred in 13 (4.8%) participants in the fluvoxamine group and 15 (5.5%) participants in the placebo group (absolute difference at day 15, 0.68%; 95% CI, -3.0% to 4.4%; log-rank CONCLUSIONS: This trial did not find fluvoxamine efficacious in preventing clinical deterioration in unvaccinated outpatients with symptomatic COVID-19. It was stopped early and underpowered due to low primary outcome rates. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov Identifier: NCT04668950