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At least 181 records · Page 10Linked to original sources

USGS2012

Environmental conditions associated with bat white-nose syndrome in the north-eastern United States

1. White-nose syndrome (WNS) is an emerging disease of hibernating North American bats that is caused by the cold-growing fungus Geomyces destructans . Since first observed in the winter of 2007, WNS has led to unprecedented mortality in several species of bats and may threaten more than 15 additional hibernating bat species if it continues across the continent. Although the exact means by which fungal infection causes mortality are undetermined, available evidence suggests a strong role of winter environmental conditions in disease mortality. 2. By 2010, the fungus G. destructans was detected in new areas of North America far from the area it was first observed, as well as in eight European bat species in different countries, yet mortality was not observed in many of these new areas of North America or in any part of Europe. This could be because of the differences in the fungus, rates of disease progression and/or in life-history or physiological traits of the affected bat species between different regions. Infection of bats by G. destructans without associated mortality might also suggest that certain environmental conditions might have to co-occur with fungal infection to cause mortality. 3. We tested the environmental conditions hypothesis using Maxent to map and model landscape surface conditions associated with WNS mortality. This approach was unique in that we modelled possible requisite environmental conditions for disease mortality and not simply the presence of the causative agent. 4. The top predictors of WNS mortality were land use/land cover types, mean air temperature of wettest quarter, elevation, frequency of precipitation and annual temperature range. Model results suggest that WNS mortality is most likely to occur in landscapes that are higher in elevation and topographically heterogeneous, drier and colder during winter, and more seasonally variable than surrounding landscapes. 5. Synthesis and applications . This study mapped the most likely environmental surface conditions associated with bat mortality owing to WNS in the north-eastern United Sates; maps can be used for selection of priority monitoring sites. Our results provide a starting point from which to investigate and predict the potential spread and population impacts of this catastrophic emerging disease.

Journal of Applied Ecology↗

USGS2019

Size-specific apparent survival rate estimates of white sharks using mark-recapture models

For species that exist at low abundance or are otherwise difficult to study, it is challenging to estimate vital rates such as survival and fecundity and common to assume that survival rates are constant across ages and sexes. Population assessments based on overly simplistic vital rates can lead to erroneous conclusions. We estimated sex and length-based annual apparent survival rates for white sharks (Carcharodon carcharias). We found evidence that annual apparent survival differed over ontogeny in a system with competitive foraging aggregations, from 0.63 (SE = 0.08) for newly recruiting sub-adults to 0.95 (SE = 0.02) for the largest sharks. Our results reveal a potential challenge to ontogenetic recruitment in a long-lived, highly mobile top marine predator, as survival rates for sub-adult white sharks may be lower than previously assumed. Alternatively, younger and competitively inferior individuals may be forced to permanently emigrate from primary foraging sites. This study provides new methodology for estimating apparent survival as a function of diverse covariates by capture-recapture study including when sex assignment is uncertain.

California↗

USGS1966

Contamination of the freshwater ecosystem by pesticides

A large part of our disquieting present-day pesticide problem is intimately tied to the freshwater ecosystem. Economic poisons are used in so many types of terrain to control so many kinds of organisms that almost all lakes and streams are likely to be contaminated. In addition to accidental contamination many pesticides are deliberately applied directly to fresh waters for suppression of aquatic animals or plants. The problem is intensified because of the extreme susceptibility of freshwater organisms. The complexity of freshwater environments and their variety makes it difficult to comprehend the total effect of pesticides.

Journal of Applied Ecology↗

USGS1966

Insecticide contaminations in wetland habitats and their effects on fish- eating birds

An unusual mortality of fish-eating birds occurred at the Tule Lake National Wildlife Refuge in California between 1960 and 1962. Over 1100 dead birds of ten species were found during that period. Investigations of the mortality indicated that birds died as a result of their exposure to toxaphene, which was applied to adjoining agricultural areas, transported to the refuge in waste irrigation water, and accumulated in fish eaten by the birds. Toxaphene was used in agriculture for only 3 years, 1958-60, and by 1962 residues were no longer found in the marsh habitat. However, results also showed that a potentially hazardous contamination of DDT and its metabolites was present in the birds and the environment. Studies were, therefore, continued to determine the food-chain relationships of DDT in marsh ecosystems, and the effects of the insecticide on birds. Sampling for insecticide residues was undertaken at four waterfowl refuges, each representing a somewhat different set of environmental conditions. DDT residues in water at each refuge were found to be relatively low, but filtered samples showed that residues in suspended material were 10 000 to 20 000 times as great as those in the filtrate. Much of the suspended material was organic matter, which is an important source of energy for the ecosystems. In environments with invertebrates, DDT residues were relatively low in sediments and high in fish, while residues in vegetation were highest where invertebrates were absent. Results suggest that organic materials and invertebrates can be important factors in determining the fate and involvement of insecticides in aquatic environments. Studies of the movements, exposure to pesticides, productivity, and longevity of individuals in three nesting colonies of White Pelicans were begun in 1962 to depict the relationships of pesticides to a migratory population of birds dependent upon wetland habitats. To date there is no evidence that the exposure of pelicans to DDT is influencing the population dynamics of the birds.

California, Oregon↗

USGS1984

Reproduction by an altricial songbird, the red-winged blackbird, in fields treated with the organophosphate insecticide fenthion

(1) Breeding red-winged blackbirds were used as a model to study the effects of a single application of an organophosphate insecticide, fenthion, on reproduction of altricial songbirds. (2) The insecticide had no significant effect on frequency of nest abandonment, clutch size, hatching success, or fledgling success. (3) Growth rates of young nestlings were lower in nests on one of two treated areas, but overall growth rates of survivors were not significantly different from controls in nests on nearby unsprayed areas. (4) The insecticide had no measured effect on male spatial organization. (5) Measures of abundance of the principal nestling food item, noctuid larvae, showed that one application of the insecticide significantly reduced the abundance of the food supply, but the reduction of food supply did not result in a decrease in nestling growth rates or fledgling success.

Wyoming↗

USGS1982

Care of nestlings by wild female starlings exposed to an organophosphate pesticide

(1) Our objective was to determine the effect of exposure to an organophosphate pesticide (OP), dicrotophos (3-hydroxy- N,N -dimethyl- cis -scrotonamide dimethyl phosphate), on care of nestlings by wild female starlings ( Sturnus vulgaris ). (2) We selected twelve pairs of active nests based on synchrony in the reproductive cycle. When nestlings were 10 days old (day 10), adult males were captured and killed and brood size was adjusted to four. The frequency and temporal distribution of sorties made by each pair of females to feed their young were recorded for 2 h at 18.00 hours on day 11 and 06.00 hours on day 12. One female from each pair was given a single oral dose of dicrotophos (2.5 mg/kg of body weight) dissolved in corn oil; the second female received an equivalent exposure of pure corn oil. Birds were released and their nestlings weighed. Parental care was again monitored between 18.00 and 20.00 hours on day 12 and 06.00 and 08.00 hours on day 13. Females were then captured and they with their young were weighed and killed. Changes in parental care in OP-dosed and control females were compared using paired t-tests. (3) The OP-dosed females made significantly ( P < 0.5) fewer sorties to feed their young and remained away from their boxes for longer periods of time than controls. Nestlings of OP-treated females lost significantly more weight ( X̄ = 9.3%) than nestlings of controls ( X̄ = 3.2%). Brain ChE activity in OP-treated females was inhibited an average of 50.7% compared with controls. Weight changes in OP-dosed ( X̄ = -8.9%) and control females ( X̄ = -8.3%) were similar. (4) Results indicate that parental care may be significantly reduced in songbirds receiving severe but sublethal exposure to organophosphate pesticides. The potential for a reduction or modification in parental care to alter reproductive success in passerines is discussed. (5) Techniques utilized, or modifications thereof, may be useful in collecting the additional data needed to adequately assess the impact of OPs on songbird reproduction.

Journal of Applied Ecology↗

USGS1983

Effects of roads on small mammals

(1) The study was designed to determine the effects of roads on the diversity, spatial distribution, and density of small mammals. (2) Forty species of small mammal (5859 individuals) were snap-trapped in the study. Data resulted from 144 360 trap-nights of effort for an average of 4.06 captures per 100 trap-nights. (3) Small mammal community structure and density were both influenced by roads. Community structure in right-of-way (ROW) habitat was different from that in adjacent habitat. Five species did not prefer ROW habitat: the golden mouse, dusky-footed woodrat, brush mouse, pinon mouse, and California red-backed vole. However, there were more species present in ROW habitat than in adjacent habitat. Grassland species generally preferred ROW habitat and many less habitat-specific species were distributed in ROW and adjacent habitat. (4) Small mammal density (all species combined) was greater in interstate ROW habitat than in adjacent habitat. This was also true individually for the eastern harvest mouse, white-footed mouse, meadow vole, prairie vole, vagrant shrew. Townsend's vole, and California vole. Small mammal density was less in county road ROWs than in adjacent habitat, probably because of the small size of these areas. The data indicate that ROW habitat and its accompanying edge are attractive no: only to grassland species but also to many less habitat-specific species that make use of the ROW-edge-adjacent habitat complex. (5) Mortality on interstate highways was greatest for those species with highest densities in ROW habitat, and did not appear to be detrimental to populations of these species.

Journal of Applied Ecology↗

USGS1987

Effects of substrate disturbance on secondary plant succession; Mojave Desert, California.

(1) The effects of substrate disturbance on perennial plant succession in the Mojave Desert were assessed at three military camps abandoned for 40 years. (2) Soil compaction, removal of the top layer of soil, and alteration of drainage channel density caused significant changes in perennial plant cover, density, and relative species composition. (3) Long-lived species, predominantly Larrea tridentata , were dominant in all control areas but percentage cover and density were greatly reduced in areas where substrate alterations were significant. (4) Pioneer species such as Ambrosia dumosa and Hymenoclea salsola had percentage cover values similar to or greater than controls in most areas where substrate alterations were significant, and these species were dominant in the majority of disturbed areas. (5) Where substrate alterations were insignificant in disturbed areas at one camp, Larrea was the dominant species as in the control.

Journal of Applied Ecology↗

USGS2008

Importance of sampling design and analysis in animal population studies: a comment on Sergio et al

1. The use of predators as indicators and umbrellas in conservation has been criticized. In the Trentino region, Sergio et al. (2006; hereafter SEA) counted almost twice as many bird species in quadrats located in raptor territories than in controls. However, SEA detected astonishingly few species. We used contemporary Swiss Breeding Bird Survey data from an adjacent region and a novel statistical model that corrects for overlooked species to estimate the expected number of bird species per quadrat in that region. 2. There are two anomalies in SEA which render their results ambiguous. First, SEA detected on average only 6.8 species, whereas a value of 32 might be expected. Hence, they probably overlooked almost 80% of all species. Secondly, the precision of their mean species counts was greater in two-thirds of cases than in the unlikely case that all quadrats harboured exactly the same number of equally detectable species. This suggests that they detected consistently only a biased, unrepresentative subset of species. 3. Conceptually, expected species counts are the product of true species number and species detectability p. Plenty of factors may affect p, including date, hour, observer, previous knowledge of a site and mobbing behaviour of passerines in the presence of predators. Such differences in p between raptor and control quadrats could have easily created the observed effects. Without a method that corrects for such biases, or without quantitative evidence that species detectability was indeed similar between raptor and control quadrats, the meaning of SEA's counts is hard to evaluate. Therefore, the evidence presented by SEA in favour of raptors as indicator species for enhanced levels of biodiversity remains inconclusive. 4. Synthesis and application. Ecologists should pay greater attention to sampling design and analysis in animal population estimation. Species richness estimation means sampling a community. Samples should be representative for the community studied and the sampling fraction among communities compared should be the same on average, otherwise formal estimation approaches must be applied to avoid misleading inference.

Journal of Applied Ecology↗

USGS2009

A cautionary note on substituting spatial subunits for repeated temporal sampling in studies of site occupancy

1. Assessing the probability that a given site is occupied by a species of interest is important to resource managers, as well as metapopulation or landscape ecologists. Managers require accurate estimates of the state of the system, in order to make informed decisions. Models that yield estimates of occupancy, while accounting for imperfect detection, have proven useful by removing a potentially important source of bias. To account for detection probability, multiple independent searches per site for the species are required, under the assumption that the species is available for detection during each search of an occupied site. 2. We demonstrate that when multiple samples per site are defined by searching different locations within a site, absence of the species from a subset of these spatial subunits induces estimation bias when locations are exhaustively assessed or sampled without replacement. 3. We further demonstrate that this bias can be removed by choosing sampling locations with replacement, or if the species is highly mobile over a short period of time. 4. Resampling an existing data set does not mitigate bias due to exhaustive assessment of locations or sampling without replacement. 5. Synthesis and applications. Selecting sampling locations for presence/absence surveys with replacement is practical in most cases. Such an adjustment to field methods will prevent one source of bias, and therefore produce more robust statistical inferences about species occupancy. This will in turn permit managers to make resource decisions based on better knowledge of the state of the system.

Journal of Applied Ecology↗

USGS2010

Potential spread of highly pathogenic avian influenza H5N1 by wildfowl: dispersal ranges and rates determined from large-scale satellite telemetry

1. Migratory birds are major candidates for long-distance dispersal of zoonotic pathogens. In recent years, wildfowl have been suspected of contributing to the rapid geographic spread of the highly pathogenic avian influenza (HPAI) H5N1 virus. Experimental infection studies reveal that some wild ducks, geese and swans shed this virus asymptomatically and hence have the potential to spread it as they move. 2. We evaluate the dispersive potential of HPAI H5N1 viruses by wildfowl through an analysis of the movement range and movement rate of birds monitored by satellite telemetry in relation to the apparent asymptomatic infection duration (AID) measured in experimental studies. We analysed the first large-scale data set of wildfowl movements, including 228 birds from 19 species monitored by satellite telemetry in 2006–2009, over HPAI H5N1 affected regions of Asia, Europe and Africa. 3. Our results indicate that individual migratory wildfowl have the potential to disperse HPAI H5N1 over extensive distances, being able to perform movements of up to 2900 km within timeframes compatible with the duration of asymptomatic infection. 4. However, the likelihood of such virus dispersal over long distances by individual wildfowl is low: we estimate that for an individual migratory bird there are, on average, only 5–15 days per year when infection could result in the dispersal of HPAI H5N1 virus over 500 km. 5. Staging at stopover sites during migration is typically longer than the period of infection and viral shedding, preventing birds from dispersing a virus over several consecutive but interrupted long-distance movements. Intercontinental virus dispersion would therefore probably require relay transmission between a series of successively infected migratory birds. 6. Synthesis and applications . Our results provide a detailed quantitative assessment of the dispersive potential of HPAI H5N1 virus by selected migratory birds. Such dispersive potential rests on the assumption that free-living wildfowl will respond analogously to captive, experimentally-infected birds, and that asymptomatic infection will not alter their movement abilities. Our approach of combining experimental exposure data and telemetry information provides an analytical framework for quantifying the risk of spread of avian-borne diseases.

Journal of Applied Ecology↗

USGS2026

Advances and applications of Unoccupied Aerial Systems (UAS) research in landscape ecology

Landscape ecologists have long depended on satellite and aerial remote sensing to address questions about landscape pattern and process, structure, and change (Foody 2023 ). Unoccupied aerial systems/vehicles (UAS/UAV, a.k.a. drones) technology is becoming an increasingly popular research tool in environmental sciences allowing scientists to generate low-cost, high-quality, and high-resolution imagery on demand that can be tailored to specific research questions. While satellite data are of a fixed resolution and temporal interval, UAS offer researchers control and flexibility to design studies and collect data at resolutions and scales that provide ecologically relevant information at finer spatial resolutions (e.g., < 30 cm) than what is currently available from satellite platforms (typically > 3m), thus helping capture objects such as individual plant canopies, micro-topography, and individual animals. Unlike satellites with fixed orbits, UAS can be deployed at more optimal temporal frequencies for ecological monitoring. We organized the special collection “Advances and Applications of Unoccupied Aerial Systems (UAS) Research in Landscape Ecology” to showcase the many ways that UAS tools and technologies are currently applied to advance landscape ecological research. When we announced the collection in 2023, only 11 papers published in the journal Landscape Ecology used UAS data, which was a notably small number compared to many other general ecology, environmental science and remote sensing journals. In an attempt to understand why UAS were not more widely used in landscape ecology and provide possible solutions, we published a review article (Villarreal et al. 2025) that identified the challenges, knowledge gaps, and obstacles for the adoption of UAS technologies in landscape ecology research. The main issues we identified include: (1) an abundance of UAS methods papers in the existing literature, with comparatively few studies demonstrating how UAS can be applied to address ecological questions; (2) a perceived scale mismatch between the geographic extent of UAS data collection (local) compared to larger study areas (landscapes) and a need to design robust scaling approaches to connect fine-scale UAS data with broader ecological patterns; and (3) a need for improved integration of UAS data with other commonly used remote sensing datasets including historical high resolution aerial imagery. Additionally, researchers new to UAS remote sensing may be discouraged or overwhelmed by the general lack of scientific consensus and standardized protocols for typical tasks such as data collection, vegetation classification, and change detection, as well as restrictive and/or confusing policy, regulatory, and legal issues surrounding UAS operations (Villarreal et al. 2025).

Landscape Ecology↗

USGS2011

Estimation of daily age and timing of hatching of exotic Asian swamp eels Monopterus albus (Zuiew, 1793) in a backwater marsh of the Chattahoochee River, Georgia, USA

Otoliths were used to estimate daily age, growth, and hatching date of the exotic Asian swamp eel ( Monopterus albus ) captured from a backwater marsh of the Chattahoochee River, Georgia, USA. The eels were sampled using leaf litter traps (N = 140) from 17 July to 28 August 2008. The captured (N = 15) Asian swamp eels ranged in total length from 4.9 cm to 12.2 cm, and were estimated to be from 21 to 51 days old (N = 13), and hatched from 13 June to 7 August 2008. Assuming linear growth, these individuals grew an average rate of 0.2 cm per day. To the authors' knowledge, this was the first time otoliths were used to estimate daily age, growth, and hatching date for M. albus , which can be useful for understanding the ecology of this species in the wild.

Journal of Applied Ichthyology↗

USGS2011

Stopover ecology of a migratory ungulate

1. Birds that migrate long distances use stopover sites to optimize fuel loads and complete migration as quickly as possible. Stopover use has been predicted to facilitate a time-minimization strategy in land migrants as well, but empirical tests have been lacking, and alternative migration strategies have not been considered. 2. We used fine-scale movement data to evaluate the ecological role of stopovers in migratory mule deer Odocoileus hemionus — a land migrant whose fitness is strongly influenced by energy intake rather than migration speed. 3. Although deer could easily complete migrations (range 18–144 km) in several days, they took an average of 3 weeks and spent 95% of that time in a series of stopover sites that had higher forage quality than movement corridors. Forage quality of stopovers increased with elevation and distance from winter range. Mule deer use of stopovers corresponded with a narrow phenological range, such that deer occupied stopovers 44 days prior to peak green-up, when forage quality was presumed to be highest. Mule deer used one stopover for every 5∙3 and 6∙7 km travelled during spring and autumn migrations, respectively, and used the same stopovers in consecutive years. 4. Study findings indicate that stopovers play a key role in the migration strategy of mule deer by allowing individuals to migrate in concert with plant phenology and maximize energy intake rather than speed. Our results suggest that stopover use may be more common among non-avian taxa than previously thought and, although the underlying migration strategies of temperate ungulates and birds are quite different, stopover use is important to both. 5. Exploring the role of stopovers in land migrants broadens the scope of stopover ecology and recognizes that the applied and theoretical benefits of stopover ecology need not be limited to avian taxa.

Journal of Animal Ecology↗

USGS2009

Maintaining the competitiveness of the American Fisheries Society journals: An assessment based on influence and cost-effectiveness

Recent changes in the landscape of scientific publishing prompted the Publications Overview Committee of the American Fisheries Society (AFS) to review the Society's portfolio of scientific journals. We evaluated journals based on metrics in two categories: (1) citation-based measures of the influence of a journal on the scientific literature, and (2) measures of the cost-effectiveness of a journal (citation rate adjusted for subscription cost). Over the long-term, we found that ecology journals had far stronger citation-based influence than fisheries and aquatic sciences journals, and that journals publishing primarily basic research had stronger influence than journals publishing applied research (including four AFS journals and Fisheries magazine). In evaluating the current status of fisheries and aquatic sciences journals, we found that metrics of influence and cost-effectiveness provided considerably different portrayals of journals relative to their peers. In terms of citation-based influence, we found that the AFS journal Transactions of the American Fisheries Society (TAFS) and Fisheries magazine were competitive with highly regarded peer fisheries journals, but that North American Journal of Aquaculture (NAJA) and Journal of Aquatic Animal Health (JAAH) were less influential than their peers. The citation-based influence of North American Journal of Fisheries Management (NAJFM) was intermediate between TAFS/Fisheries and NAJA/JAAH . For journals like NAJFM and NAJA , we expect that much of the scientific influence on policy and management is not captured by citations in the primary literature, and alternative methods of evaluation may be needed. All of the AFS journals ranked highly with regard to cost-effectiveness because their subscription costs are low, and these rankings are in accordance with membership needs and the strategic mission of AFS to provide broad and timely dissemination of scientific information. We conclude by suggesting ways to increase the influence of AFS journals without compromising their accessibility and affordability, and offer advice about methods and frequency for future journal evaluations.

Fisheries↗

USGS2019

Age and growth of Freshwater Drum and Gizzard Shad occupying two reservoir-river complexes with different groundwater contributions

Restoring groundwater flow is a management option that improves water temperature regimes and benefits fishes. Although this strategy applies more readily to river systems, the thermal character of reservoirs is heavily influenced by inflowing rivers. We examined differences in age, structure, and growth of both Freshwater Drum Aplodinotus grunniens and Gizzard Shad Dorosoma cepedianum that occupy catchments with varying groundwater contributions in the south‐central United States. Seepage run data indicated that the Kiamichi River was losing surface water to groundwater in summer 2016, whereas groundwater inflows were apparent in the Elk River basin. Summer 2016 data showed that the Elk River had cooler water temperatures than the Kiamichi River and Grand Lake O’ the Cherokees water temperatures were similar to those in the incoming Elk River. We found higher densities of older Freshwater Drum and Gizzard Shad (maximums of 32 and 8 years old, respectively) in samples from the Grand basin than among fish that were sampled from the Kiamichi River basin (21 and 6 years old, respectively). Freshwater Drum grew at similar rates in both basins even though they reached larger maximum lengths in the Grand basin (649 mm TL) than in the Kiamichi River basin (600 mm). The average asymptotic length was greater for the Kiamichi population ( L ∞ = 613 mm) than for the Grand population ( L ∞ = 557 mm). Gizzard Shad from the Grand basin were larger than those from the Kiamichi River basin, though the latter population grew faster initially (Brody growth coefficient: K = 0.787 versus K = 0.179, respectively), but they had smaller asymptotic length ( L ∞ = 206 mm versus L ∞ = 343 mm). The role that groundwater plays in temperature regulation in these basins partially explains the observed differences. Our results suggest that the metabolic theory of ecology can be applied to fisheries management at a finer spatial scale.

Oklahoma↗

USGS2021

Modeling areal measures of campsite impacts on the Appalachian National Scenic Trail to enhance ecological sustainability

Campsite impacts in protected natural areas are most effectively minimized by a containment strategy that focuses use on a limited number of sustainable campsites that spatially concentrate camping activities. This research employs spatial autoregressive (SAR) modeling to evaluate the relative influence of use-related, environmental, and managerial factors on two salient measures of campsite impact. Relational analyses examined numerous field-collected and GIS-derived indicators, including several new indicators calculated using high-resolution Light Detection and Ranging (LiDAR) topographic data to evaluate the influence of terrain characteristics on the dependent variables. Chosen variables in the best SAR models explained 35% and 30% of the variation in campsite size and area of vegetation loss on campsites. Results identified three key indicators that managers can manipulate to enhance the sustainability of campsites: campsite type, and terrain characteristics relating to landform slope and topographic roughness. Results support indirect management methods that rely on the location, design, construction, and maintenance of campsites, instead of direct regulations that restrict visitation or visitor freedoms. As visitation pressures continue to increase, this knowledge can be applied to select and promote the use of more ecologically sustainable campsites.

Connecticut, Georgia, Maine, Maryland, Massachuset↗

USGS2011

Seasonal distribution of Gulf of Mexico sturgeon in the pensacola bay system, Florida

Temporal and spatial distributions of Gulf of Mexico (Gulf) sturgeon Acipenser oxyrinchus desotoi were assessed in the Pensacola bay system, Florida, using stationary ultrasonic telemetry. Fifty‐eight Gulf sturgeon were tagged within the Escambia (n = 26), Yellow (n = 8), Blackwater (n = 12) and Choctawhatchee Rivers (n = 12) in June, July, September and October, 2005. Fifty‐four Gulf sturgeon were detected at least once during the study. Migration of sturgeon occurred throughout the bay system in fall, to various winter habitats in the Gulf of Mexico and Santa Rosa Sound. In spring, tagged sturgeon migrated back through the bay system to summer habitats in rivers. Based on the duration and number of detections, Gulf sturgeon primarily used the upper portions of East and Escambia Bays as migration routes in and out of all rivers during spring and summer and inhabited the lower portion of Pensacola Bay for longer durations in fall and winter. Specific areas within the Pensacola bay system were used in summer and winter that were not previously documented as essential sturgeon habitat. Areas in southeastern Pensacola Bay were heavily used during winter by a large portion of the population. Gulf sturgeon also exhibited long‐term winter residency in Santa Rosa Sound for two consecutive years. An area in northeastern Escambia Bay supported Gulf sturgeon during the summer, which was unexpected and can not be explained by the data from this study. However, the discovery that Gulf sturgeon remain in the bay during the summer has important ecological and management implications that need further investigation.

Florida↗