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Genetic discontinuity among regional populations of Lophelia pertusa in the North Atlantic Ocean
Lophelia pertusa reef at approximately 400 meters depth off of North Carolina as seen from the Johnson-Sea-Link manned submersible. Photo credit: Cheryl Morrison, USGS.
Lophelia pertusa reef at approximately 400 meters depth off of North Carolina as seen from the Johnson-Sea-Link manned submersible. Photo credit: Cheryl Morrison, USGS.

Ecologically important habitat is created on continental margins by the nearly cosmopolitan deep-sea coral Lophelia pertusa. Such reefs are increasingly threatened by human activities such as destructive fishing practices, and energy exploration and drilling. Effective protection and avoidance measures for deep L. pertusa reefs requires knowledge of the patterns and scales of coral larval dispersal that connect reefs, potentially allowing re-population following destructive events. We examined patterns of genetic connectivity across a large portion of the range of L. pertusa in the North Atlantic Ocean. We found four distinct genetic groupings that correspond to ocean regions: Gulf of Mexico, coastal southeastern U.S., New England Seamounts, and eastern North Atlantic Ocean. Given the apparent isolation among regions, an effective management scheme involves regional reserve networks.
Citation: Morrison, C. Genetic discontinuity among regional populations of Lophelia pertusa in the North Atlantic Ocean; Conservation Genetics 2011, 12: 713-729. Morrison et al. or go to:

For more information, contact: Cheryl Morrison, Leetown Science Center.

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USGS Biologist Recipient of Ornithological Research Award
Photo: Miller medal ceremony--medal given by Cooper Orn Society President and USGS scientist Mercedes Foster.
Photo: Miller medal ceremony--medal given by Cooper Orn Society President and USGSscientist Mercedes Foster.

USGS wildlife biologist Susan M. Haig received the 2011 Loye and Alden Miller Research Award at the Cooper Ornithological Society annual meeting in Kearney, NE on March 12th. The award recognizes lifetime achievement in ornithological research. Haig research interests include conservation genetics, avian behavioral ecology, population connectivity, and endangered species policy.
Susan M. Haig, Forest and Rangeland Ecosystem Science Center.

Posted: May 6, 2011

Genetic Assessments of Jabiru Storks Important for Conservation
Photo: Jabiru storks (Jabiru mycteria) in Brazil. Photo credit: © 2010 Susan Haig, USGS
Photo: Jabiru storks (Jabiru mycteria) in Brazil. Photo credit: © 2010 Susan Haig, USGS.

Jabiru storks (Jabiru mycteria) are large waterbirds that are found in wetland areas in Central America, northern South America, and southern Brazil. They are considered regionally threatened in Central America due to habitat loss. Little is known about the current and historic population structure of jabirus. USGS scientist Susan Haig and co-authors from Brazil used genetic tools to provide the first species-wide assessment of jabiru storks over their entire range. They also compared historic and contemporary genetic diversity in birds from the same locations. Findings showed lower levels of genetic diversity in Central and northern South American populations when compared to the Brazilian population. If genetic structure is a goal of management agencies, reconnection of populations, particularly in Central America, would be important. The information will be beneficial to the development of conservation strategies to restore genetic diversity in all populations.
Lopes, I.F., Haig, S.M., Del Lama, S.N., 2010, Genetic characterization of neotropical jabiru storks- Insights for conservation: Waterbirds, v. 33, no. 4, p. 425-437. Catalog No: 1740.

For more information view the study description Genetic Characterization of Neotropical Jabiru Storks- Insights for Conservation and contact Susan M. Haig, Forest and Rangeland Ecosystem Science Center.

Posted: March 28, 2011

 
Interspecific Exchange Of Avian Influenza Virus Genes In Alaska: The Influence Of Trans-Hemispheric Migratory Tendency And Breeding Ground Sympatry

A male northern pintail duck. Photo credit: John Pearce, USGS
Photo: Two mallards (Anas platyrhynchos) float in a city lake. Photo credit: © 2008 Elizabeth A. Sellers, Courtesy of

The movement and transmission of avian influenza viral strains via wild migratory birds may vary by host species as a result of migratory tendency and sympatry with other infected individuals.  A 50-year band recovery data set of Mallards in North America suggests that unlike Northern Pintail ducks, Mallards rarely make trans-hemispheric migrations between Alaska and Eurasia.  Concordantly, fewer low pathogenic avian influenza viruses from Mallards contained Eurasian gene segments compared to those from Northern Pintails.  Aerial survey and banding data suggest that Mallards and Northern Pintails are largely sympatric throughout Alaska during the breeding season, promoting opportunities for interspecific transmission.  Comparisons of viruses from these two species confirmed nearly identical genomes in seven cases.  These results suggest that Mallards are unlikely to transfer Asian origin viruses directly to North America via Alaska, but that they are likely infected with Asian origin viruses via interspecific transfer from species with migratory connectivity to the Eastern Hemisphere.

For more information contact John Pearce, Alaska Science Center.

Abstract: Interspecific Exchange Of Avian Influenza Virus Genes In Alaska: The Influence Of Trans-Hemispheric Migratory Tendency And Breeding Ground Sympatry

Posted: March 9, 2011

Effects of Mercury on Reproductive Function in Fish and Associated Gene Expression
Zebrafish. Photo credit: ZFIN and Oregon Zebrafish Laboratories
Zebrafish. Photo credit: ZFIN and Oregon Zebrafish Laboratories

Mercury is a widespread contaminant in aquatic systems throughout the United States, due to direct inputs and atmospheric deposition.  In aquatic systems, elemental mercury is transformed to methylmercury, enhancing its toxicity to the brain and reproductive system.  USGS researchers are conducting three related investigations of functional genomics of methylmercury exposure in fish, using goldfish, fathead minnow, and zebrafish, and defining gene expression profiles in the brain, liver, and gonad.

Posted: February 7, 2011

Reintroduction of Rehabilitated Manatees Calves in Brazil
Photo: Manatees are netted and brought into a boat for health assessments and tracking studies in Brazil, Michael Lusk, USFWS. Credit: Margaret Hunter, USGS.
Photo: Manatees are netted and brought into a boat for health assessments and tracking studies in Brazil, Michael Lusk, USFWS. Credit: Margaret Hunter, USGS.

Molecular studies were used to determine genetically-appropriate source populations for the release of rehabilitated manatee calves in Brazil. The critically endangered Northeast region population is estimated to have ~300 manatees with the main cause of mortality attributed to the stranding of neonate calves. It has been suggested that pregnant females are not gaining access to protected estuarine waters because of habitat destruction and shrimp farms and become separated from their calves shortly after birth. A total of 67 rescued calves have been rehabilitated at the Center for Aquatic Mammals in Brazil for release to the wild population. Using mitochondrial DNA, extremely low diversity and two genetic groups with a central mixing zone were identified in the wild population. Additionally it was determined that a number of rehabilitated calves have been released to the unrelated population in the past. Future releases into related populations would help to limit outbreeding depression or genetic swamping and help to encourage the recovery of the small Brazilian manatee population.

For more information contact Margaret E. Hunter at the Southeast Ecological Science Center.

Abstract: Phylogeographic implications for release of critically endangered manatee calves rescued in Northeast Brazil.

Posted: April 1, 2013

Low Genetic Diversity Detected in the Endangered Florida Manatee Population
Photo: Endangered Florida manatee in Crystal River, FL. Photo credit: Dr. Robert Bonde, USGS.
Photo: Endangered Florida manatee in Crystal River, FL. Photo credit: Dr. Robert Bonde, USGS.

Species of management concern that have been affected by human activities typically are characterized by low genetic diversity, which can adversely affect their ability to adapt to environmental changes. Therefore, genetic diversity and population structure was estimated in 362 Florida manatees at 18 microsatellite markers. All measures of Florida manatee genetic diversity were less than the averages reported for placental mammals, including fragmented populations. Slight, but significant genetic differentiation was detected between the East and West coasts of Florida and the demographically defined management units. Although genetic issues appear not to be critical at present, the Florida manatee continues to face demographic challenges due to anthropogenic activities and stochastic factors such as red tides, oil spills, and disease outbreaks; these can further reduce genetic diversity of the manatee population.

For more information, contact Dr. Margaret Hunter at the USGS Southeast Ecological Science Center or Dr. Kimberly Tucker, director of STEM initiatives at Stevenson University.

Posted: April 1, 2013

Using Diets to Reveal Overlap and Egg Predation among Benthivorous Fishes in Lake Michigan
Photo: Rainbow trout from the South Fork Boise River. Photo Credit: Jason Dunham, USGS.
Photo: Deepwater sculpin from the Great Lakes. Photo Credit: Justin Londer.

Ecological stability in the Laurentian Great Lakes has been altered by nonindigenous species, such as the round goby Neogobius melanostomus and dreissenid mussels, and by declines in native amphipods Diporeia spp. We evaluated whether these changes could influence diet overlap between three benthivorous fishes (slimy sculpin Cottus cognatus, deepwater sculpin Myoxocephalus thompsonii, and round goby) and whether predation on eggs of native species was occurring. We determined diets of fish collected from Lake Michigan between January and May in 2009 and 2010 using morphological and genetic species identification. Important prey for slimy sculpin were Mysis, Diporeia, and Limnocalanus macrurus; important prey for deepwater sculpin were Mysis and Diporeia. Round goby consumed mainly bivalves and Mysis. Genetic analyses revealed that the two sculpin species consumed the eggs of bloaters (Coregonus hoyi) and deepwater sculpin between February and May at all sites. Round goby also consumed eggs of these species but at lower levels. Diet overlap was identified between sculpin species at Frankfort and Sturgeon Bay, suggesting possible interspecific competition; diet overlap was never observed between round goby and either sculpin species. Given that (1) diet overlap varied by site and (2) diet proportions varied spatially more than temporally, benthivores appear to be exhibiting localized responses to recent ecological changes. Overall, these results reveal that egg predation and interspecific competition could be important interactions to consider in future examinations of the population dynamics of these species or in ecosystem models that forecast how fisheries will respond to possible perturbations or management scenarios.

Mychek-Londer, J. et al. 2013. Diet overlap and food habits of slimy sculpin, deepwater sculpin, and round goby during winter and spring in offshore Lake Michigan. Transactions of the American Fisheries Society. 142:492-504.

For more information, contact Justin Mycheck-Londer, David ‘Bo’ Bunnell or Wendylee Stott at the Great Lakes Science Center.

Posted: June 6, 2013

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