Sweat S.C.,Georgia College & State University |
Sweat S.C.,Tennessee Aquarium Conservation Institute |
Mutiti S.,Georgia College & State University |
Skelton C.E.,Georgia College & State University
Wetlands Ecology and Management | Year: 2017
Crayfish are important in wetland systems because of their function in soil nutrient turnover. Since many crayfishes are imperiled by anthropogenic activities, it is important to understand factors that are associated with their distribution within and among wetlands. This study investigated the soil and hydrogeological characteristics of a wetland and related them to the spatial distribution of crayfish burrows found within it. The study utilized field-collected soil cores, electrical resistivity, and ground penetrating radar to map subsurface characteristics at Bartram Forest, Baldwin County, Georgia. Wetland delineation was also conducted in the field to establish the wetland boundaries. Both 2D and 3D geophysical profiles were created. Soils samples were analyzed for grain size distribution, porosity, and hydraulic conductivity in the lab. Hydraulic conductivity of the wetland soils was also determined in the field using slug tests. Results show subsurface physical differences between crayfish inhabited zones of the wetland and those that do not have crayfish burrows.The Ambiguous Crayfish, Cambarus striatus was found in soils with a hydraulic conductivity of 0.01–0.4 m/day where soils outside of their colony boundary had a hydraulic conductivity of 0.4–1.2 m/day. Areas where C. striatus were located had a higher porosity (0.36) than areas without crayfish (0.26). Subsurface stratigraphy varied between the areas with and without burrows. C. striatus was found to live in a subsurface with relatively gradual stratigraphical boundaries when compared to surrounding areas. © 2017 Springer Science+Business Media Dordrecht
Chen X.-Y.,CAS Kunming Institute of Zoology |
Kottelat M.,Route de la Baroche 12 |
Kottelat M.,National University of Singapore |
Neely D.A.,California Academy of Sciences |
Neely D.A.,Tennessee Aquarium Conservation Institute
Ichthyological Exploration of Freshwaters | Year: 2011
Physoschistura yunnaniloides, new species, is described from the Chindwin River drainage, Sagaing Division, Myanmar. It is distinguished from all its congeners except P. shanensis by having a complete lateral line. It seems related to P. shanensis in morphology but can be distinguished by its pointed snout, 18-20 transverse bars along lateral side of body, fewer branched dorsal-fin rays, fewer branched pectoral-fin rays, a greater pre-pelvic length, a more slender caudal-peduncle, a higher dorsal fin, and a shorter pelvic fin. © 2011 by Verlag Dr. Friedrich Pfeil, München, Germany.
News Article | November 3, 2016
For the Barrens Topminnow, conditions couldn’t get much worse. After months with little to no rain, the Middle Tennessee stream that serves as a vital habitat to one of the last remaining wild populations of endangered Barrens Topminnows has all but dried up. The once sparkling water has been reduced to a series of stagnant pools connected by an anemic trickle of murky water. After monitoring the ecological impact of the region’s exceptional drought for months, representatives from the Tennessee Aquarium Conservation Institute (TNACI) and U.S. Fish and Wildlife Service visited this critical stream on a farm north of Manchester, Tenn., to determine how bad conditions were and whether a rescue effort was warranted. As he looked out on the drought-ravaged scene, however, Tennessee Aquarium Aquatic Biologist Dr. Bernie Kuhajda realized the situation was even worse than anticipated. “I thought it’d be dry. I had no idea there’d be practically no water here,” Dr. Kuhajda said. “I don’t have a lot of hope. This was by far the healthiest population of Barrens Topminnows anywhere. This is pretty cataclysmic.” Despite its diminutive size and limited range, the Barrens Topminnow is part of a delicate ecosystem. Ensuring its survival is crucial to preserving the natural balance of the entire waterway, said Clay Raines, Tennessee Aquarium reintroduction biologist. “All we know for sure is that the more species you have, the more stable the ecosystem is,” he said. “You lose that chain, and no one can say, for certain, what those foundational species are — who’s most important and who’s least important — in that ecosystem. We have to value all aquatic life equally and preserve what we can.” The Middle Tennessee stream system, a tributary waterway of Lewis Creek, once contained hundreds of fish and served as habitat to a large percentage of the two remaining wild populations of Barrens Topminnows known to exist. As they sifted through the grubby catch of each seine net haul from the puddle-thin water, however, the team were finding found just a handful of Barrens Topminnows. Worse yet, they were disconcerted to discover plentiful Western Mosquitofish, a hardy invasive species which preys on Barrens Topminnow young. Mosquitofish had not been found in this tributary before. “The presence of Mosquitofish getting in these upstream headwater habitats is pretty disheartening,” said the Tennessee Aquarium’s Assistant Curator of Fishes Matt Hamilton, whose involvement in the Barrens Topminnow recovery program dates back to 1999. Once Mosquitofish begin to reproduce, he said, the demise of the Barrens Topminnows will become an almost foregone conclusion. “It’ll be a numbers game at that point,” he said. “Mosquitofish numbers are going to increase, and the Barrens Topminnows are going to decrease. These topminnows are a short-lived species, so it won’t be long until they are gone.” When environmental conditions become bad enough to place an entire species’ survival at risk, conservation scientists sometimes resort to bringing an entire wild population into human care to create an “ark population” to safeguard against the possibility of extinction. Within the Southeast, many such captive populations and propagation programs soon will be housed at TNACI’s flagship freshwater field station near downtown Chattanooga. This state-of-the-art facility on the banks of the Tennessee River opened on Oct. 27 and already serves as the headquarters for propagation programs for Southern Appalachian Brook Trout and Lake Sturgeon. After two and a half hours of work and dozens of seine hauls, the field team recovered just 64 Barrens Topminnows, an amount that previously could have been acquired in a single net drag. These individuals were placed in bags of clean, oxygenated water and taken to a TNACI facility as part of a new ark population. “Without taking this last-resort action, this population would be gone forever,” said Dr. Kuhajda. “Now there’s hope to keep this genetically distinct population intact with the long-term goal of re-establishing a healthy population here again.” The drought conditions are having a dramatic impact on many species throughout the Southeast’s extremely bio-diverse waterways. After witnessing the devastated conditions they found in Middle Tennessee, TNACI representatives will visit sites on Walden Ridge near Spring City, Tenn. This is one of the few remaining locations where the federally endangered Laurel Dace is found. If the streams conditions prove to be as bone-dry as the spring-fed waters in Middle Tennessee, whatever Laurel Dace remain will be rescued for another ark population. In the Cherokee National Forest, the ongoing exceptional drought and record-high temperatures have resulted in streams that are shallower, slower-flowing and warmer. These conditions are wreaking havoc on the native Southern Appalachian Brook Trout, whose habitat was already just 12 percent of its historical extent. Trout, which prefer cooler water, are concentrating in deeper pools. At lower elevations, their proximity to one another is leading to increased rates of disease and predation, said Jim Herrig, a forest aquatic biologist with the U.S. Forest Service Forest. “When we get to higher elevations, the larger streams are suffering really bad,” he said. “The water is getting so warm that the trout aren’t able to persist.” The Southern Appalachian Brook has been the subject of a long-term, collaborative restoration effort between TNACI, the U.S. Forest Service and the Tennessee Wildlife Resources Agency. Thanks to the reduced water flow, however, the facilities involved in this effort have been largely shuttered. “Nobody is going to be raising any Brook Trout this year,” Herrig said. The U.S. Fish and Wildlife Service has found a similarly deadly byproduct of the drought in a mass die-off of mussels in the Clinch River system of Northeast Tennessee and Southwest Virginia, where water levels are a fraction what they were in wetter months. “It’s definitely the driest we’ve ever seen it, and it’s been dry all around the state,” said Stephanie Chance, a USFWS listing and candidate conservation biologist, who assisted with the Barrens Topminnow recovery. “It’s troubling.” The work of conserving native species is complex and, in times like these, frustrating for biologists. Healthy populations of aquatic animals can deal with natural cycles that bring periods of drought, disease or other environmental stresses. But, when a species is already on the brink, the tipping point is easier to reach. Kuhajda believes shoring up these fragile ecosystems requires considering the important role fresh water plays in our daily lives and doing everything we can to safeguard it. “When our rivers and streams dry up, people really focus on water,” he said. “But we should be thinking about our most important resource throughout the year.” About Barrens Topminnows: Size: Up to 4 inches Range: Found only on the Barrens Plateau of Middle Tennessee Conservation Status: Endangered in Tennessee and currently under review for listing by the U.S. Fish and Wildlife Service. If approved, this species would be protected under the Endangered Species Act. Threats: The introduction of the Western Mosquitofish, which eats very young Barrens Topminnows, drought, water quality, and alteration of springs and small streams. Conservation Efforts: The Tennessee Aquarium monitors the Barrens Topminnow population and has worked with conservation partners to release more than 44,000 Barrens Topminnows into their natural habitat. Aquarium guests can see this ongoing work inside the Barrens Topminnow Lab Exhibit, which is located in the River Journey building.
News Article | October 28, 2016
With the October 27 opening of the Tennessee Aquarium Conservation Institute’s (TNACI) new flagship riverfront facility, the Southeast’s rich — but imperiled — aquatic biodiversity is going to receive a much-needed shot in the arm. TNACI’s facility sits at the heart of a region whose aquatic diversity is unrivaled in the temperate world. More than 1,400 aquatic species reside in waterways within a 500-mile radius of Chattanooga, including about three-quarters (73.1 percent) of all native fish species in the United States. More than 90 percent of all American mussels and crayfish species live within that same area, as do 80 percent of North America’s salamander species and half of its turtle species. “Many people don’t realize that we live within one of the world’s great biodiversity hotspots — home to an underwater rainforest,” said TNACI Director Dr. Anna George. “There are as many fish species in the Cumberland, Mobile, and Tennessee River basins as there are in a similarly-sized part of the Amazon River.” The increased research and outreach capabilities offered by the TNACI facility arrive at a critical time for these aquatic treasures, which increasingly are imperiled by human encroachment and a lack of federal funding. The Southeast has fewer protected lands than western states, and the absence of buffer zones and heavy development around local waterways place already-fragile and limited freshwater ecosystems at even greater risk. Habitat destruction in the region is exacerbating the withering experienced by all freshwater species, whose rate of extinction is two to five times higher than that of terrestrial and marine animals. Federal spending on research to protect the Southeast’s freshwater species is pauper-poor and drastically out of proportion to the region’s incredible ecological diversity. Between 2012 and 2014, total expenditure on programs to study freshwater fish species in the Southeast averaged $6.2 million. During the same period, just 12 species outside the region received a combined $636 million in funding, more than 100 times the average budget for the entire Southeast. With so much attention being focused on less biodiverse areas, TNACI’s new home offers a one-of-a-kind opportunity to raise the profile of southeastern rivers and streams, as well as lead the charge on conservation science in the region. And as an arm of a nonprofit aquarium, TNACI is ideally positioned to pursue this mission across the region, Dr. George said. “We have a special ability to work across traditional borders on collaborative projects that bring people together to protect the exceptional aquatic life of the southeastern United States,” she said. “We can then share our scientific work with the Aquarium’s large and diverse audience to inspire others to join us in celebrating and protecting the animals living in the rivers and streams of our backyards.” Located near a natural wetland along the banks of the Tennessee River just downstream from downtown Chattanooga, the 14,000-square-foot facility will serve as the headquarters for a newly bolstered staff of conservation scientists as well as visiting experts. Featuring an environmentally conscious design that informed every aspect of its construction, the building provides access to cutting-edge equipment, including genetics and morphology laboratories, and offers much-needed space for staff to centralize and streamline ongoing projects, initiate critical new research with partners across the country, and host educational programs. “We’re surrounded by amazing freshwater communities that are unparalleled for diversity and beauty,” said TNACI director Dr. Anna George. “It’s why our region is so exciting to the scientific community and why we are committed to protecting our aquatic riches so they can continue to be enjoyed by all. This new science center will give us more capacity to expand our research, restoration and education programs.” Since TNACI’s foundation in 1996, its staff has pursued projects to study and, in some cases, restore some of the region’s most imperiled species, including long-term captive propagation of Lake Sturgeon and Southern Appalachian Brook Trout. Previously, those programs were managed at separate off-site locations, some more than 45 minutes away from Chattanooga. They now will be housed on the first floor of the new building in a space specifically designed for the animals’ needs. Even with the newly relocated programs, additional square footage has been reserved at the site to expand TNACI’s propagation efforts in the future. The building’s dedicated genetics laboratory will ease the research process and increase the capabilities of TNACI staff. Formerly, institute researchers conducting DNA testing worked at a makeshift station in a corner of the Aquarium’s Animal Care Facility. By bringing together formerly far-flung projects and offering access to lab equipment that can more effectively handle research needs on-site, the new facility eliminates many of the obstacles that previously hampered TNACI’s conservation efforts, said Dr. Bernie Kuhajda, director of the facility’s science programs. The site also will serve as a nexus for conservation science beyond Chattanooga, with office and research space on the second floor specifically designated for use by visiting scientists. “Just getting together to work collaboratively with our team was always logistically challenging since we were in separate buildings,” he said. “Now, we'll have all our field gear, all our labs and offices in one place. A huge part of the benefit is this new shared space, which not only helps us work together more closely, but also gives us space to bring together fellow scientists from across the country to discuss conservation solutions.” Although it is just now officially opening its doors, the new facility already is the hub of numerous active conservation programs, including: In addition to its scientific initiatives in the field, TNACI’s new facility also will serve to bolster the institute’s educational outreach. A large teaching lab on the first floor will target regional high school and college students who are pursuing a degree in a scientific field and connect them with freshwater scientists and educators. For more information about TNACI, its new facility and its conservational initiatives, visit http://www.tnaqua.org/protect-freshwater. Follow the institute on social media via http://www.facebook.com/TennesseeAquariumConservationInstitute or http://www.twitter.com/tnacigogreen. The Tennessee Aquarium inspires wonder, appreciation and protection of water and all life that it sustains. Admission is $29.95 per adult and $18.95 per child, ages 3-12. Each ticket purchased helps support Aquarium conservation programs. The IMAX® 3D Theater is next door to the Aquarium. Ticket prices are $11.95 per adult and $9.95 per child. Aquarium/IMAX combo tickets are $37.95 for adults and $26.95 for children. Excursions aboard the new River Gorge Explorer depart daily into “Tennessee’s Grand Canyon.” Cruise tickets are $32.00 per adult and $24.50 per child (3-12). Advance tickets may be purchased online at http://www.tnaqua.org or by phone at 1-800-262-0695. The Aquarium, located on the banks of the Tennessee River in Chattanooga, is a non-profit organization. Open every day except Thanksgiving and Christmas, the Aquarium and IMAX are accessible to people with disabilities. High resolution images of the new science center and TNACI experts in the field are available for download: https://we.tl/1vsADkX1O2 Drone footage of the new science center: https://youtu.be/eqHAZqsB1yg (***Be sure to check full HD setting***) Tennessee Aquarium Conservation Institute – Freshwater Biodiversity video for embed: https://www.youtube.com/watch?v=RcHca5yUZME
Ennen J.R.,Tennessee Aquarium Conservation Institute |
Davenport J.M.,Southeast Missouri State University |
Alford K.F.,Tennessee Aquarium Conservation Institute
Hydrobiologia | Year: 2016
The importance of competition among stream salamanders and other stream vertebrates in headwater systems is understudied. We conducted a replicated artificial stream experiment to evaluate competitive interactions among three common vertebrates. In this experiment, we measured change in body condition of salamanders in the black-bellied dusky complex (Desmognathus quadramaculatus/folkertsi) in the presence of two different fish species, Common Creek Chub (Semotilus atromaculatus) and Coosa Darter (Etheostoma coosae). There was no statistically significant change in body condition between the control and darter present treatments. However, salamander body condition was significantly reduced in the presence of the creek chubs suggesting an asymmetric competitive interaction between those two species. While predation is often cited as a potential mechanism limiting the distribution of stream species, the role of interspecific competition may be just as vital. Overall, our results highlight that competition, and not solely predation, may explain why some stream salamanders are restricted to headwater reaches. © 2016 Springer International Publishing Switzerland
Chen X.-Y.,CAS Kunming Institute of Zoology |
Neely D.A.,California Academy of Sciences |
Neely D.A.,Tennessee Aquarium Conservation Institute
Zootaxa | Year: 2012
Schistura albirostris, a new species of nemacheiline loach, is described from the Longchuanjiang, a tributary of the Irrawaddy River of Tengchong County, southwestern Yunnan, China. It differs from all congeners in the combination of an extremely slender body; a distinctive rectangular unpigmented area on the snout, ethmoid region and anterior rostral barbels; 5-7 dark dorsal saddles that are confluent with 5-8 lateral bars; lacking a suborbital flap in males; and possessing an incomplete lateral line with 27-51 pores, and a weakly-developed processus dentiformis. Copyright © 2001-2012 Magnolia Press.
Fluker B.L.,University of Alabama |
Kuhajda B.R.,University of Alabama |
Kuhajda B.R.,Tennessee Aquarium Conservation Institute |
Harris P.M.,University of Alabama
Freshwater Biology | Year: 2014
Riverine impoundments (reservoirs) are thought to impede natural migration in small-stream-inhabiting fishes, resulting in spatially and genetically fragmented populations. However, this hypothesis remains poorly tested, and the genetic consequences of riverine impoundment for stream fishes with differing dispersal capabilities are not well understood. This study utilised a combination of microsatellite DNA loci from 479 individuals and the mitochondrial (mt) DNA cytochrome b gene (810-1140 bp) from 83 individuals from eight streams to compare genetic structure and diversity between reservoir-fragmented and non-fragmented groups of two species of stream fishes with differing dispersal capabilities in the Mobile River basin of the south-eastern United States. For both species, analysis of microsatellite loci revealed genetic discontinuities between neighbouring tributaries that have been fragmented by reservoir construction. This finding was in stark contrast to the high degree of continuity for both species between reference tributaries in a natural river setting. Results from mtDNA revealed no significant genetic structure within reservoir-fragmented or non-fragmented groups, indicating a lack of historical genetic structure (i.e. prior to reservoir construction). Microsatellite-based estimates of genetic diversity and migration were differentially affected in the two species, indicating that stream fishes with relatively high dispersal abilities may be equally or more susceptible to reservoir fragmentation when compared to species with relatively low dispersal abilities. Collectively, our data revealed that riverine impoundment and reservoir-induced habitat fragmentation adversely affect genetic characteristics in small-stream-inhabiting fishes. This is of particular interest in biodiversity hotspots such as the south-eastern United States where hydroelectric and recreational reservoirs restrict connectivity in aquatic systems. © 2013 John Wiley & Sons Ltd.
Ennen J.R.,Tennessee Aquarium Conservation Institute |
Lindeman P.V.,Edinboro University of Pennsylvania |
Lovich J.E.,U.S. Geological Survey
Ecology and Evolution | Year: 2015
Coloration can play critical roles in a species' biology. The allometry of color patterns may be useful for elucidating the evolutionary mechanisms responsible for shaping the traits. We measured characteristics relating to eight aspects of color patterns from Graptemys oculifera and G. flavimaculata to investigate the allometric differences among male, female, and unsexed juvenile specimens. Additionally, we investigated ontogenetic shifts by incorporating the unsexed juveniles into the male and female datasets. In general, male color traits were isometric (i.e., color scaled with body size), while females and juvenile color traits were hypoallometric, growing in size more slowly than the increase in body size. When we included unsexed juveniles in our male and female datasets, our linear regression analyses found all relationships to be hypoallometric and our model selection analysis found support for nonlinear models describing the relationship between body size and color patterns, suggestive of an ontogenetic shift in coloration traits for both sexes at maturity. Although color is critical for many species' biology and therefore under strong selective pressure in many other species, our results are likely explained by an epiphenomenon related to the different selection pressures on body size and growth rates between juveniles and adults and less attributable to the evolution of color patterns themselves. © 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
George A.L.,Tennessee Aquarium Conservation Institute |
Hamilton M.T.,Tennessee Aquarium |
Alford K.F.,Tennessee Aquarium Conservation Institute
International Zoo Yearbook | Year: 2013
Freshwater ecosystems in the south-eastern United States, a global hotspot for temperate aquatic biodiversity, are increasingly threatened by human activity. For 14 years, the Tennessee Aquarium Conservation Institute has partnered with many other organizations to lead reintroduction programmes for Lake sturgeon Acipenser fulvescens and Barrens topminnow Fundulus julisia. Consistent with our educational mission, new interactive exhibits and outreach programmes have been designed to connect more visitors with these programmes on-site. While aquariums and zoos are natural partners to fulfil the public outreach needs of recovery teams, they have equally important roles within the project team to lead in propagation and reintroduction science. New research initiatives into best practices in captive propagation and conservation planning for imperilled fishes provide scientific leadership to our conservation community that also gives credibility to our work. By preparing for a long-term investment and continuing to foster the good relationships already in place with the public and partners, we hope to continue building upon the success of our reintroduction programmes. © 2012 The Zoological Society of London.
News Article | February 15, 2017
After more than a year of data collection, analysis and mapping, the University of Georgia River Basin Center and the Tennessee Aquarium Conservation Institute recently published a comprehensive survey of aquatic animals in Southeastern watersheds. This first-of-a-kind study used information on where aquatic animals live gathered directly from field researchers, universities, museums and government agencies. The report’s creators hope it will serve as a call to action for protection and restoration, helping to chart future conservation efforts in the region. Among scientists, the Southeast is renowned as a hotspot for freshwater wildlife, but the life that teems beneath the surface of its rivers and streams — a veritable underwater rainforest — remains relatively unknown to the general public. After decades of being overlooked, conservationists think the time has come for the region to take its rightful place in the spotlight. “The Southeast’s rich aquatic communities are globally significant. There’s nothing else like our biodiversity anywhere else on the continent or anywhere else in the temperate world,” said Dr. Duncan Elkins, the study’s coordinator and a postdoctoral research associate at the University of Georgia River Basin Center. All southeastern states have incredible aquatic life, but the study spotlights areas with higher diversity and at greater risk of imperilment. Take one look at the report’s heat maps, and the Southeast’s ecological significance becomes impossible to ignore. The maps use colors to represent the variety of species in a given area — warmer colors indicating greater diversity — and are based on the distribution of almost 1,050 fish, crayfish and mussel species in almost 300 watersheds spanning 11 states. The vivid red-and-orange bullseye centered on Middle and Southeast Tennessee, Northwest Georgia and Northern Alabama clearly shows why this region is so biologically significant. “The Southeast has an incredible number of species, and it's really important that we focus our attention on protecting places where we can get the most bang for our buck,” said Tennessee Aquarium Conservation Institute Director Dr. Anna George. By highlighting the region’s most diverse watersheds, the study will help to focus future scientific research and guide conservation groups to areas where intervention can have the greatest impact. “The need is great for us to act to protect our species,” George continued. “This project allows us to visualize, across the Southeast, where those places are that are so critically important for our water and wildlife.” Scientists “scored” each watershed based on three characteristics: the number of species it contained, the conservation status of those species and how widespread each species was. Areas containing a larger variety of species, many endangered or threatened species or species found in few or no other locations were ranked higher. According to the study, the 10 highest-priority watersheds are: The story of the Southeast’s freshwater ecology is one of both unrivaled diversity and rampant imperilment. Experts place the region’s plethora of aquatic wildlife on equal footing with that of species-rich tropical ecosystems. More than 1,400 species reside in waterways within a 500-mile radius of Chattanooga, Tenn., including about three-quarters (73.1 percent) of all native fish species in the United States. More than 90 percent of all American mussel and crayfish species live within that same area. More than a quarter of the species included in the study are found nowhere else in the world, yet 28 percent of Southeastern fish species are considered imperiled, more than doubling during the last 20 years fueled by intensive human development and a lack of financial support for regional conservation efforts. The publication of the Tennessee Aquarium Conservation Institute and River Basin Center study, which was created through a National Fish and Wildlife Foundation grant, comes at a crucial time for Southeastern aquatic ecosystems. Efforts to study and safeguard freshwater species in the region continue to struggle due to anemic funding and a lack of federally protected lands, especially compared to less-diverse regions, such as the Western United States. The study’s creators say they hope it will serve as a master plan to guide research and conservation work that will ensure the long-term survival of waterways that dramatically impact the human communities that rely on them. “Rivers and streams in the U.S. are the arteries that flow through our landscape, and they carry a measure of the health of the landscape with them,” George said. “Right now, those rivers are having heart attacks. “What we're doing is like visiting a doctor to learn how to take better care of the health of our rivers. We’ve identified some of the most important places to start a small change in our habits and how we take care of our waters. And over time, just like walking a mile turns into running a race, those small changes will add up to big differences for the health of the country’s rivers and streams.’”