Conceptual model of salt marsh management on Merritt Island National Wildlife Refuge, Florida: final report

Diking and holding water on salt marshes ("impounding" the marsh) is a management technique used on Merritt Island National Wildlife Refuge (MINWR) and elsewhere in the Southeast to: a) prevent the reproduction of saltmarsh mosquitos, and b) attract wintertering waterfowl and other marsh, shore, and wading birds. Because of concern that diking and holding water may interfere with the production of estuarine fish and shellfish, impoundment managers are being asked to consider altering management protocol to reduce or eliminate any such negative influence. How to change protocol and preserve effective mosquito control and wildlife management is a decision of great complexity because: a) the relationships between estuarine organisms and the fringing salt marshes at the land-water interface are complex, and b) impounded marshes are currently good habitat for a variety of species of fish and wildlife. Most data collection by scientists and managers in the area has not been focused on this particular problem. Furthermore, collection of needed data may not be possible before changes in protocol are demanded. Therefore, the purpose of this document is two-fold: 1) to suggest management alternatives, given existing information, and 2) to help identify research needs that have a high probability of leading to improved simultaneous management of mosquitos, waterfowl, other wildlife, freshwater fish, and estuarine fish and shellfish on the marshland of the Merritt Island National Wildlife Refuge. (92 page document

Categorized bibliography for a conceptual model of salt marsh management on Merritt Island, Florida

Enclosed is a bibliography of 556 published articles, technical reports, theses, dissertations, and books that form the basis for a conceptual model of salt marsh management on Merritt Island, Florida (Section 1). A copy of each item is available on file at the Florida Cooperative Fish and Wildlife Research Unit, Gainesville. Some relevant proprietary items and unpublished drafts have not been included pending permission of the authors. We will continue to add pertinent references to our bibliography and files. Currently, some topics are represented by very few items. As our synthesis develops, we will be able to indicate a subset of papers most pertinent to an understanding of the ecology and management of Merritt Island salt marshes. (98 page document

Nesting Habitat and Behavior of Spiny Softshell Turtles Apalone Spinifera Hartwegi in the Missouri River, MT

Little is known about the nesting behavior and habitat of the western spiny softshell (Apalone spinifera hartwegi) in Montana where they are at the northern extent of their range and are a state Species of Concern. Our objective was to document nesting behavior, habitat, and timing in a 97-kilometer reach of the Missouri River. We radio-tagged 47 female turtles and attempted to locate nesting areas using telemetry, visual surveys from jet boat and on foot, and by observation from shore-based blinds. We located 27 nests; 15 were on islands, 12 were aggregated, and 2 were depredated. Nesting occurred following the peak river stage from about July 7 to July 28. Twenty-three nests were in mixed gravel and 4 nests were in sand substrates. Distance from water’s edge to the nest ranged from 1.9 m to 27 m and height of nest above the water surface elevation ranged from 0.25 m to 1.9 m. Vegetation at nest sites was sparse, ranging from 0 to 15 percent vegetative cover. Emergence of hatchlings was documented for 17 nests and occurred from about September 1 to September 20. All 17 successful nests were in gravel substrate; we did not document any emergence from nests in sand. Lack of emergence from sand nests may be related to the cumulative thermal regime in the nest chamber during the period from peak discharge until the onset of freezing in autumn. In 2012, we will investigate the thermal environment in gravel and sand nesting substrates

Nesting Ecology of Spiny Softshell Turtles on the Missouri River in Montana: Zoogeographic and Management Implications

The nesting ecology of western spiny softshell turtles (Apolone spinifera hartwegi) in Montana, where they are at the northern extent of their range and a state Species of Concern, is poorly known. We used telemetry, visual surveys, observation from shore-based blinds, and remote cameras to document nesting behavior, habitat, and timing in a 97-km reach of the Missouri River. We located 25 nests in 2011 and 97 in 2012. Most nests were in mixed-gravel substrates; only 3 percent were in pure sand. Vegetative cover at nest sites was sparse. Mean distance of nests to the water’s edge was 13.7 m and mean height above the water surface elevation was 0.7 m. Proportion of nests found on island and mainland habitats were similar in 2011, but 90 percent of nests were on islands in 2012. Predation occurred on 46 nests; mainland nests incurred higher predation rates than island nests. Nesting followed annual peak river stage, and mostly occurred in the afternoon. Durations of nesting, incubation, and emergence periods were similar in both years, but nesting and emergence occurred about three weeks later in 2011 than in 2012. Only 36 percent of nests were successful in 2011, but 60 percent were successful in 2012. Flooding in 2011 probably decreased nesting effort and success by reducing habitat availability and delaying the onset of nesting, which thereby prematurely ended incubation. However, flood events maintain and create nesting habitats by clearing vegetation and depositing substrates. Premature termination of incubation suggests that the northern range of this species is probably limited by successful incubation

Nesting Ecology of Spiny Softshell Turtles on the Missouri River in Montana: Zoogeographic and Management Implications

The nesting ecology of western spiny softshell turtles (Apolone spinifera hartwegi) in Montana, where they are at the northern extent of their range and a state Species of Concern, is poorly known. We used telemetry, visual surveys, observation from shore-based blinds, and remote cameras to document nesting behavior, habitat, and timing in a 97-km reach of the Missouri River. We located 25 nests in 2011 and 97 in 2012. Most nests were in mixed-gravel substrates; only 3 percent were in pure sand. Vegetative cover at nest sites was sparse. Mean distance of nests to the water’s edge was 13.7 m and mean height above the water surface elevation was 0.7 m. Proportion of nests found on island and mainland habitats were similar in 2011, but 90 percent of nests were on islands in 2012. Predation occurred on 46 nests; mainland nests incurred higher predation rates than island nests. Nesting followed annual peak river stage, and mostly occurred in the afternoon. Durations of nesting, incubation, and emergence periods were similar in both years, but nesting and emergence occurred about three weeks later in 2011 than in 2012. Only 36 percent of nests were successful in 2011, but 60 percent were successful in 2012. Flooding in 2011 probably decreased nesting effort and success by reducing habitat availability and delaying the onset of nesting, which thereby prematurely ended incubation. However, flood events maintain and create nesting habitats by clearing vegetation and depositing substrates. Premature termination of incubation suggests that the northern range of this species is probably limited by successful incubation

Evaluation of Visible Implant Elastomer Tags in Wild Coastal Cutthroat Trout in the Marine Environment

We evaluated the detectability of visible implant elastomer (VIE) tags in Coastal Cutthroat TroutOncorynchus clarkii clarkiiin the marine environment by comparing visually identified recaptures from VIE tags with known recaptures that were identified through genotype matching. A total of 89 individual Coastal Cutthroat Trout were marked in the lower jaw with colored VIE tags, sampled for genetics, and recaptured across 12 months in 2015. The rate of correspondence between the VIE tags and genetic matches was 92% (82/89) of the recaptured Coastal Cutthroat Trout in the nearshore marine environment. We found that red- and blue-colored VIE tags were detected at a higher rate (100%) than were yellow- and orange-colored tags (87.3% and 90.6%, respectively). In contrast, tag type (single or double), tag location (left or right), fish length (FL, mm), and time (days) since tagging had no effect on tag detectability during the study period. All of the tag colors were recovered for the maximum life of the study (up to 342 days). In all of the cases of nondetections (5/89), the tags were not identified upon initial recapture or subsequent capture events, suggesting that they were lost or not visible immediately upon insertion in the field-as opposed to being unidentified due to the degradation of tag detectability over time. The results of this study suggest that VIE tags have the potential to be detectable in juvenile and adult Coastal Cutthroat Trout for at least 12 months after insertion, with blue and red performing the best. Additional monitoring extending beyond 12 months after tagging would be necessary to identify the maximum life of VIE tags

Thermal Stability of the Human Immunodeficiency Virus Type 1 (HIV-1) Receptors, CD4 and CXCR4, Reconstituted in Proteoliposomes

BACKGROUND: The entry of human immunodeficiency virus (HIV-1) into host cells involves the interaction of the viral exterior envelope glycoprotein, gp120, and receptors on the target cell. The HIV-1 receptors are CD4 and one of two chemokine receptors, CCR5 or CXCR4. METHODOLOGY/PRINCIPAL FINDINGS: We created proteoliposomes that contain CD4, the primary HIV-1 receptor, and one of the coreceptors, CXCR4. Antibodies against CD4 and CXCR4 specifically bound the proteoliposomes. CXCL12, the natural ligand for CXCR4, and the small-molecule CXCR4 antagonist, AMD3100, bound the proteoliposomes with affinities close to those associated with the binding of these molecules to cells expressing CXCR4 and CD4. The HIV-1 gp120 exterior envelope glycoprotein bound tightly to proteoliposomes expressing only CD4 and, in the presence of soluble CD4, bound weakly to proteoliposomes expressing only CXCR4. The thermal stability of CD4 and CXCR4 inserted into liposomes was examined. Thermal denaturation of CXCR4 followed second-order kinetics, with an activation energy (E(a)) of 269 kJ/mol (64.3 kcal/mol) and an inactivation temperature (T(i)) of 56°C. Thermal inactivation of CD4 exhibited a reaction order of 1.3, an E(a) of 278 kJ/mol (66.5 kcal/mol), and a T(i) of 52.2°C. The second-order denaturation kinetics of CXCR4 is unusual among G protein-coupled receptors, and may result from dimeric interactions between CXCR4 molecules. CONCLUSIONS/SIGNIFICANCE: Our studies with proteoliposomes containing the native HIV-1 receptors allowed an examination of the binding of biologically important ligands and revealed the higher-order denaturation kinetics of these receptors. CD4/CXCR4-proteoliposomes may be useful for the study of virus-target cell interactions and for the identification of inhibitors

Effective monitoring of freshwater fish

Freshwater ecosystems constitute only a small fraction of the planet’s water resources, yet support much of its diversity, with freshwater fish accounting for more species than birds, mammals, amphibians, or reptiles. Fresh waters are, however, particularly vulnerable to anthropogenic impacts, including habitat loss, climate and land use change, nutrient enrichment, and biological invasions. This environmental degradation, combined with unprecedented rates of biodiversity change, highlights the importance of robust and replicable programmes to monitor freshwater fish assemblages. Such monitoring programmes can have diverse aims, including confirming the presence of a single species (e.g. early detection of alien species), tracking changes in the abundance of threatened species, or documenting long-term temporal changes in entire communities. Irrespective of their motivation, monitoring programmes are only fit for purpose if they have clearly articulated aims and collect data that can meet those aims. This review, therefore, highlights the importance of identifying the key aims in monitoring programmes, and outlines the different methods of sampling freshwater fish that can be used to meet these aims. We emphasise that investigators must address issues around sampling design, statistical power, species’ detectability, taxonomy, and ethics in their monitoring programmes. Additionally, programmes must ensure that high-quality monitoring data are properly curated and deposited in repositories that will endure. Through fostering improved practice in freshwater fish monitoring, this review aims to help programmes improve understanding of the processes that shape the Earth's freshwater ecosystems, and help protect these systems in face of rapid environmental change

Entrainment of ichthyoplankton by a warmwater hydroelectric facility

The authors examined entrainment of ichthyoplankton associated with hydropowergeneration in 1988 and 1989 at the Pensacola Dam hydroelectric facility on Grand Lake innortheastern Oklahoma. To provide a basis for evaluating the effects of entrainment on the fishassemblage, they also estimated the total abundance of fish eggs and larvae in the top 10 m ofthe reservoir. Entrainment totalled about 10 million larval fish in 1988 and almost 100 million in1989. Only nine taxa of larval fish were entrained during the study. Entrained eggs were almostexclusively those of freshwater drum Aplodinotus grunniens. Although estimates of entrainmentwere large, they were generally low compared with the estimates of total abundance ofichthyoplankton in Grand Lake