Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Manatee Subspecies Genetically Confirmed, But Diversity Challenge Looms

14.09.2010
Two Belize Populations Offer Opportunity in a Desert of Genetic Diversity

The first genetic study to compare nuclear DNA of endangered Antillean manatees in Belize with Florida manatees confirmed their designation as separate subspecies. Belize’s manatees, however, were found to have extremely low genetic diversity, raising questions about their long-term genetic viability.

The Central American country of Belize hosts the largest known breeding population of Antillean manatees and is touted by biologists for its potential to repopulate other parts of Central America where manatees are severely reduced, rare or absent.

“It turns out that the genetic diversity of Belize’s manatees is lower than some of the classic examples of critically low diversity” said U.S. Geological Survey (USGS) conservation geneticist Margaret Hunter, Ph.D., who led a molecular DNA study of genetic diversity in the Antillean subspecies in Belize.

Belize’s Antillean populations scored lower in genetic diversity than textbook examples of “bottlenecked" endangered species such as Wanglang giant pandas, the East African cheetah and an island koala population founded by only three koalas.

Endangered species need genetic diversity to weather threats to their survival, including random or rare shocks such as disease, hurricanes or habitat destruction. When a population drops to low numbers, the diversity of its gene pool also shrinks. Even after it rebounds to greater numbers, that population decline leaves a legacy of reduced genetic diversity known as a bottleneck. This renders the population more vulnerable to future shocks, explained Hunter.

The low genetic diversity in Antillean manatees is attributed, in part, to centuries of hunting that were only curtailed early in the 20th century. Once found throughout coastal regions of Central and South America, Antillean manatees are now rare or absent in parts of Central America where they used to be considered abundant. Today, even Belize only hosts about 1,000 individuals — a number well below the threshold recommended for long-term sustainability, said Hunter.

Distinct Populations Offer Opportunity

Although the study found low overall genetic diversity in Belize, notable differences were found in manatees that live near Belize City compared to manatees living in lagoons, rivers, and cayes farther

south. These differences, said Hunter, equate to genetic variation, which is valuable for sustaining a diverse gene pool.

“When it comes to the sustainability of a species, this is the type of genetic diversity you want to preserve for the future,” explained Hunter.

To sustain the diverse gene pool these populations offer, managers will need to consider methods of enabling natural migration and mixing to take place between the two populations.

“These results show the importance of corridors of suitable habitat and low human impact that allow manatees to travel between key sites,” said co-author Nicole Auil Gomez, a Belizean biologist who does consulting for the Florida-based conservation organization Sea 2 Shore Alliance.

“Leaving pockets of habitat is no longer enough,” she added.

Confirmation of the Subspecies

The genetic evidence that Florida manatees (Trichechus manatus latirostris) are not regularly mixing with populations of Antillean manatees (Trichechus manatus manatus) in Belize means they don’t naturally affect each other’s population size or genetic diversity, Hunter said.

The question of whether these two seemingly distant populations were interbreeding had been raised in light of radiotracking evidence that manatees are capable of migrating long distances. Florida manatees have turned up in places as far as Rhode Island, the Bahamas and Cuba.

The only prior genetic data comparing the subspecies came from mitochondrial DNA, which is useful for understanding historical relationships on an evolutionary time scale (think millennia, not decades). By including nuclear DNA, this study provided a modern-day assessment of whether the two populations are migrating and interbreeding.

“We are continuing to piece together the genetic relationships of manatees throughout the Caribbean and it’s giving us insights into how to maintain healthy and stable populations,” said USGS biologist and co-author Bob Bonde, Ph.D.

The study, Low genetic variation and evidence of limited dispersal in the regionally important Belize manatee, was recently published in the journal Animal Conservation.

More information about USGS research on manatee genetics can be found on the USGS Sirenia Project website.

Rachel Pawlitz | EurekAlert!
Further information:
http://www.usgs.gov

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>