30 results match your criteria: "Southeast Ecological Science Center[Affiliation]"

Frequencies of decision making and monitoring in adaptive resource management.

PLoS One

October 2017

Southeast Ecological Science Center, U.S. Geological Survey, Gainesville, Florida, United States of America.

Adaptive management involves learning-oriented decision making in the presence of uncertainty about the responses of a resource system to management. It is implemented through an iterative sequence of decision making, monitoring and assessment of system responses, and incorporating what is learned into future decision making. Decision making at each point is informed by a value or objective function, for example total harvest anticipated over some time frame.

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Influence of Manatees' Diving on Their Risk of Collision with Watercraft.

PLoS One

August 2016

Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 Eighth Ave. SE, St. Petersburg, FL, 33710, United States of America.

Watercraft pose a threat to endangered Florida manatees (Trichechus manatus latirostris). Mortality from watercraft collisions has adversely impacted the manatee population's growth rate, therefore reducing this threat is an important management goal. To assess factors that contribute to the risk of watercraft strikes to manatees, we studied the diving behavior of nine manatees carrying GPS tags and time-depth recorders in Tampa Bay, Florida, during winters 2002-2006.

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Statistical Models for the Analysis and Design of Digital Polymerase Chain Reaction (dPCR) Experiments.

Anal Chem

November 2015

Southeast Ecological Science Center, U.S. Geological Survey , 7920 NW 71st Street, Gainesville, Florida 32653, United States.

Statistical methods for the analysis and design of experiments using digital PCR (dPCR) have received only limited attention and have been misused in many instances. To address this issue and to provide a more general approach to the analysis of dPCR data, we describe a class of statistical models for the analysis and design of experiments that require quantification of nucleic acids. These models are mathematically equivalent to generalized linear models of binomial responses that include a complementary, log-log link function and an offset that is dependent on the dPCR partition volume.

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We used repeated sightings of individual birds encountered in community-level surveys to investigate the relative roles of habitat and biological interactions in determining the distribution and abundance of each species. To analyze these data, we developed a multispecies N-mixture model that allowed estimation of both positive and negative correlations between abundances of different species while also estimating the effects of habitat and the effects of errors in detection of each species. Using a combination of single- and multispecies N-mixture modeling, we examined for each species whether our measures of habitat were sufficient to account for the variation in encounter histories of individual birds or whether other habitat variables or interactions with other species needed to be considered.

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Habitat suitability index (HSI) models are commonly used to predict habitat quality and species distributions and are used to develop biological surveys, assess reserve and management priorities, and anticipate possible change under different management or climate change scenarios. Important management decisions may be based on model results, often without a clear understanding of the level of uncertainty associated with model outputs. We present an integrated methodology to assess the propagation of uncertainty from both inputs and structure of the HSI models on model outputs (uncertainty analysis: UA) and relative importance of uncertain model inputs and their interactions on the model output uncertainty (global sensitivity analysis: GSA).

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Species distribution models (SDM) link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species' ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems.

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Article Synopsis
  • Environmental DNA (eDNA) methods help detect low-density species and improve occupancy models to estimate detection probabilities, but inconsistent terminology has led to issues in applying these methods in studies.
  • In southern Florida, visual surveys and traps have struggled to effectively estimate the occupancy of invasive giant constrictor snakes, which threaten local ecosystems like the Everglades.
  • Researchers developed specific eDNA assays for various constrictor species, successfully detecting Burmese pythons in numerous sampling events, leading to valuable insights for conservation and management efforts in the region.
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Enhanced understanding of ectoparasite-host trophic linkages on coral reefs through stable isotope analysis.

Int J Parasitol Parasites Wildl

April 2015

Department of Biological Sciences, Arkansas State University, PO Box 599, State University, AR 72467, USA.

Parasitism, although the most common type of ecological interaction, is usually ignored in food web models and studies of trophic connectivity. Stable isotope analysis is widely used in assessing the flow of energy in ecological communities and thus is a potentially valuable tool in understanding the cryptic trophic relationships mediated by parasites. In an effort to assess the utility of stable isotope analysis in understanding the role of parasites in complex coral-reef trophic systems, we performed stable isotope analysis on three common Caribbean reef fish hosts and two kinds of ectoparasitic isopods: temporarily parasitic gnathiids (Gnathia marleyi) and permanently parasitic cymothoids (Anilocra).

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To address the ongoing debate over the impact of invasive species on native terrestrial wildlife, we conducted a large-scale experiment to test the hypothesis that invasive Burmese pythons (Python molurus bivittatus) were a cause of the precipitous decline of mammals in Everglades National Park (ENP). Evidence linking pythons to mammal declines has been indirect and there are reasons to question whether pythons, or any predator, could have caused the precipitous declines seen across a range of mammalian functional groups. Experimentally manipulating marsh rabbits, we found that pythons accounted for 77% of rabbit mortalities within 11 months of their translocation to ENP and that python predation appeared to preclude the persistence of rabbit populations in ENP.

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The "value of information" (VOI) is a generic term for the increase in value resulting from better information to guide management, or alternatively, the value foregone under uncertainty about the impacts of management (Yokota and Thompson, Medical Decision Making 2004; 24: 287). The value of information can be characterized in terms of several metrics, including the expected value of perfect information and the expected value of partial information. We extend the technical framework for the value of information by further developing the relationship between value metrics for partial and perfect information and describing patterns of their performance.

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Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and therefore represent a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and performed de novo assembly of the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome and that a subset of these substitutions were in genes evolving under positive selection and putatively associated with a marine phenotype.

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Northern Gulf of Mexico (NGoM) loggerheads (Caretta caretta) make up one of the smallest subpopulations of this threatened species and have declining nest numbers. We used satellite telemetry and a switching state-space model to identify distinct foraging areas used by 59 NGoM loggerheads tagged during 2010-2013. We tagged turtles after nesting at three sites, 1 in Alabama (Gulf Shores; n = 37) and 2 in Florida (St.

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Marine and inland fishes of St. Croix, U. S. Virgin Islands: an annotated checklist.

Zootaxa

May 2014

U. S. Geological Survey, Southeast Ecological Science Center, 7920 NW 71st Street, Gainesville, Florida 32653, USA.; Email:

An historical account is given for the ichthyological research at St. Croix, U. S.

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We developed a statistical model to estimate the abundances of potentially interacting species encountered while conducting point-count surveys at a set of ecologically relevant locations - as in a metacommunity of species. In the model we assume that abundances of species with similar traits (e.g.

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Selective serotonin reuptake inhibitors (SSRIs) have been reported to range from low parts per trillion to parts per billion levels in surface waters, wastewater effluents, and sediments. These low levels have led to concern for their potential long-term risks to the survival, growth, and reproduction of aquatic organisms. We investigated the acute and chronic effects of sertraline on the life history traits of Ceriodaphnia dubia over the course of three generations under environmentally realistic concentrations.

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In capture-recapture and mark-resight surveys, movements of individuals both within and between sampling periods can alter the susceptibility of individuals to detection over the region of sampling. In these circumstances spatially explicit capture-recapture (SECR) models, which incorporate the observed locations of individuals, allow population density and abundance to be estimated while accounting for differences in detectability of individuals. In this paper I propose two Bayesian SECR models, one for the analysis of recaptures observed in trapping arrays and another for the analysis of recaptures observed in area searches.

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Total mercury concentrations in lionfish (Pterois volitans/miles) from the Florida Keys National Marine Sanctuary, USA.

Mar Pollut Bull

January 2014

School of Natural Resources and Environment, University of Florida, 103 Black Hall, Gainesville, FL 32611, USA; Fisheries and Aquatic Sciences Program, School of Forest Resources and Conservation, University of Florida, 7922 NW 71st Street, Gainesville, FL 32653, USA. Electronic address:

Strategies to control invasive lionfish in the western Atlantic and Caribbean are likely to include harvest and consumption. Until this report, total mercury concentrations had been documented only for lionfish from Jamaica, and changes in concentrations with increasing fish size had not been evaluated. In the Florida Keys, total mercury concentrations in dorsal muscle tissue from 107 lionfish ranged from 0.

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Anthropogenic semivolatile organic compounds (SOCs) that persist in the environment, bioaccumulate, are toxic at low concentrations, and undergo long-range atmospheric transport (LRT) were identified and quantified in the atmosphere of a Saharan dust source region (Mali) and during Saharan dust incursions at downwind sites in the eastern Caribbean (U.S. Virgin Islands, Trinidad and Tobago) and Cape Verde.

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Article Synopsis
  • N-mixture models help estimate species abundance using repeated point count surveys while adjusting for the fact that not all individuals are detected.
  • An extension of these models tackles issues like rarity, which causes more zero detections than expected, and correlated behaviors that complicate detection rates among surveys.
  • The new model incorporates a hurdle model for abundance and a beta-binomial model for detectability, improving flexibility in estimating species occurrence, mean abundance, and detection probabilities, as demonstrated with the West Indian manatee.
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Nesting strategies and use of important in-water habitats for far-ranging marine turtles can be determined using satellite telemetry. Because of a lack of information on habitat-use by marine turtles in the northern Gulf of Mexico, we used satellite transmitters in 2010 through 2012 to track movements of 39 adult female breeding loggerhead turtles (Caretta caretta) tagged on nesting beaches at three sites in Florida and Alabama. During the nesting season, recaptured turtles emerged to nest 1 to 5 times, with mean distance between emergences of 27.

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Coral, fish, plankton, and detritus samples were collected from coral reefs in Virgin Islands National Park (VIIS) and Virgin Islands Coral Reef National Monument (VICR) to assess existing contamination levels. Passive water sampling using polar organic chemical integrative samplers (POCIS) and semi-permeable membrane devices found a few emerging pollutants of concern (DEET and galaxolide) and polynuclear aromatic hydrocarbons. Very little persistent organic chemical contamination was detected in the tissue or detritus samples.

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Invasive species represent an increasing threat to native ecosystems, harming indigenous taxa through predation, habitat modification, cross-species hybridization and alteration of ecosystem processes. Additionally, high economic costs are associated with environmental damage, restoration and control measures. The Burmese python, Python molurus bivittatus, is one of the most notable invasive species in the US, due to the threat it poses to imperiled species and the Greater Everglades ecosystem.

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Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate.

Biology (Basel)

March 2013

Cherokee Nation Technology Solutions, Contracted to U.S. Geological Survey, Southeast Ecological Science Center, 7920 NW 71st Street, Gainesville, FL 32653, USA.

The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change-that of extreme variation in precipitation-may have on amphibians.

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Several models have been developed to predict the geographic distribution of a species by combining measurements of covariates of occurrence at locations where the species is known to be present with measurements of the same covariates at other locations where species occurrence status (presence or absence) is unknown. In the absence of species detection errors, spatial point-process models and binary-regression models for case-augmented surveys provide consistent estimators of a species' geographic distribution without prior knowledge of species prevalence. In addition, these regression models can be modified to produce estimators of species abundance that are asymptotically equivalent to those of the spatial point-process models.

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