(Press-News.org) Using data obtained during six years of regular aerial surveys and genetics data collected by a consortium of research groups, scientists have strengthened evidence pointing to the central Gulf of Maine as a mating ground for North Atlantic right whales, according to a study recently published online in the journal Endangered Species Research.
The North Atlantic right whale (Eubalaena glacialis) is one of the most endangered marine mammal species in the world and has been intensively studied for decades. Much has been learned about its habitat, behavior, and population demographics. But until now, there was little to indicate where these whales mated, a big missing piece in the puzzle of their life history.
"A high proportion of potential mates aggregated in the central Gulf of Maine between November and January, and these same individuals produced a calf a year later. We concluded that this is a pretty strong indication of a mating ground if the gestation period is 12 months," said Tim Cole, lead author and a biologist at the Woods Hole Laboratory of NOAA's Northeast Fisheries Science Center (NEFSC).
Through aerial surveys, the researchers documented not only how many but also which right whales were present in the study area during 2002-2008. Individual animals were identified using a photo identification catalog maintained at the New England Aquarium that includes most of the adults in the population. Using genetic data gathered in other field work, known fathers seen in the surveys were identified, as were known mothers, who were identified by association with a calf.
The resulting analyses showed that the animals seen included a higher proportion of reproductively successful animals than were present in other areas that these whales used seasonally. The researchers further assumed a 12-month gestation period for North Atlantic right whales, similar to that estimated for the closely-related southern right whale (Eubalaena australis) by the South African whale biologist Dr. Peter Best.
How definitive is the study? Cole says that while it's a strong indicator, there could well be other mating areas, and its not clear how fixed the areas might be. In fact, since the study ended, fewer right whales have been observed in the area during what would be the mating period. The study also found a similar, if less dramatic, indication that Roseway Basin - an area south of Nova Scotia - may also serve as a mating ground.
"We are still seeing right whales in the central Gulf of Maine, just not in the same numbers. They are still out there, but where they all are in the big question. The decline is significant, so something appears to have changed," Cole said. "The good news is that calf production has been fairly good, with 22 calves born in 2011, 7 in 2012, and 20 this past winter. It will be interesting to see how many calves are born next year."
Most of the North Atlantic right whale population spends the spring and summer on feeding grounds off the northeastern U.S. and the Canadian Maritimes. In late fall and early winter, pregnant females migrate to waters off the southeastern U.S. to give birth. Mothers and calves are detected during intensive aerial surveys conducted from December through March off the coasts of Florida, Georgia, South Carolina, and North Carolina. Mothers and calves return to the northeast feeding grounds in the early spring, and the calves stay with their mothers for a year following birth.
Recovery of this endangered species depends on successful reproduction, but current reproductive rates for North Atlantic right whales are much lower than those for the recovering populations of southern right whales. The reasons for this are unknown, but may include a low level of genetic variability and /or inbreeding, disease, biotoxins, pollutants, food supply limitations, and habitat loss. Increased ocean noise from coastal development could also impact the species by triggering behavioral changes that negatively impact reproduction. Determining the right whale's conception period and mating grounds are important steps in learning about the factors that may be impairing reproduction.
###
In addition to Cole, study authors included Allison Glass Henry, Peter Duley and Richard Pace from NOAA's Northeast Fisheries Science Center; Philip Hamilton from the New England Aquarium; Bradley White from Trent University in Ontario, Canada; and Tim Frasier from St. Mary's University in Halifax, Nova Scotia, Canada.
Are North Atlantic right whales mating in the Gulf of Maine?
2013-07-25
ELSE PRESS RELEASES FROM THIS DATE:
Newly discovered marine viruses offer glimpse into untapped biodiversity
2013-07-25
Researchers of the University of Arizona's Tucson Marine Phage Lab have discovered a dozen new types of unknown viruses that infect different strains of marine bacteria.
Bacteriophages – viruses that prey on bacteria – are less familiar to most people than their flu- or cold-causing cousins, but they control processes of global importance. For example, they determine how much oxygen goes from the oceans into the atmosphere in exchange for carbon dioxide, they influence climate patterns across the Earth and they alter the assemblages of microorganisms competing in the ...
New genetic cause of pulmonary hypertension identified
2013-07-25
NEW YORK, NY (July 25, 2013) — Columbia University Medical Center (CUMC) scientists have identified new genetic mutations that can cause pulmonary arterial hypertension (PAH), a rare fatal disease characterized by high blood pressure in the lungs. The mutations, found in the gene KCNK3, appear to affect potassium channels in the pulmonary artery, a mechanism not previously linked to the condition. Cell culture studies showed that the mutations' effects could be reversed with a drug compound known as a phospholipase inhibitor. The study was published today in the online ...
Boreal forests in Alaska becoming more flammable
2013-07-25
A 2,000-square-kilometer zone in the Yukon Flats of interior Alaska--one of the most flammable high-latitude regions of the world--has seen a dramatic increase in both the frequency and severity of fires in recent decades, according to research funded by the National Science Foundation (NSF).
Wildfire activity in this area is higher than at any other time in the past 10,000 years, the researchers report.
The research, funded by NSF's Division of Polar Programs, adds to the evidence that relatively frequent and powerful fires are converting the conifer-rich boreal ...
New Notre Dame study proposes changes in New Orleans area levee systems
2013-07-25
Less may mean more when it comes to the levee systems designed to protect New Orleans from hurricanes.
That's the conclusion of a new study by a team of University of Notre Dame researchers led by Joannes Westerink, co-developer of the authoritative computer model for storm surge used by the U.S. Army Corps of Engineers, the Federal Emergency Management Agency (FEMA) and the state of Louisiana to determine water levels due to hurricane surge and to design levee heights and alignments.
The lower Mississippi River south of New Orleans protrudes into the Gulf of Mexico ...
Potential cause of Parkinson's disease points to new therapeutic strategy
2013-07-25
LA JOLLA, CA – July 24, 2013 – Biologists at The Scripps Research Institute (TSRI) have made a significant discovery that could lead to a new therapeutic strategy for Parkinson's disease.
The findings, recently published online ahead of print in the journal Molecular and Cell Biology, focus on an enzyme known as parkin, whose absence causes an early-onset form of Parkinson's disease. Precisely how the loss of this enzyme leads to the deaths of neurons has been unclear. But the TSRI researchers showed that parkin's loss sharply reduces the level of another protein that ...
Seeing photosynthesis from space: NASA scientists use satellites to measure plant health
2013-07-25
NASA scientists have established a new way to use satellites to measure what's occurring inside plants at a cellular level.
Plants grow and thrive through photosynthesis, a process that converts sunlight into energy. During photosynthesis, plants emit what is called fluorescence – light invisible to the naked eye but detectable by satellites orbiting hundreds of miles above Earth. NASA scientists have now established a method to turn this satellite data into global maps of the subtle phenomenon in more detail than ever before.
Healthy plants use the energy from sunlight ...
Obese kidney failure patients receive survival benefit from transplantation
2013-07-25
Most obese individuals with kidney failure can prolong their lives by receiving a kidney transplant, although this survival benefit is lower in severely obese individuals. That's the conclusion of a new study published in the American Journal of Transplantation. The findings will hopefully decrease differences in access to transplantation for obese patients.
Obesity is increasing in patients with kidney failure. In some studies, obese kidney failure patients who are on dialysis have a lower risk of dying prematurely than non-obese patients. In contrast, obese kidney ...
Flow restrictors may reduce young children's accidental ingestion of liquid medications
2013-07-25
Cincinnati, OH -- In the US, child-resistant packaging for most medications has contributed to the prevention of thousands of pediatric deaths. Nevertheless, over 500,000 calls are made to poison control centers each year after accidental ingestion of medications by young children, and the number of emergency department visits for unsupervised medication ingestions is rising. In a new study scheduled for publication in The Journal of Pediatrics, researchers studied whether adding flow restrictors to bottles can limit the amount of liquid medication a child could access ...
Over 90 percent of dementia cases in China are undetected
2013-07-25
An international team of researchers has found that over 90 percent of dementia cases in China go undetected, with a high level of undiagnosed dementia in rural areas. The team of public health experts led by Dr Ruoling Chen at King's College London argues that more mental health education targeting high-risk populations is now needed to improve diagnosis rates, and increase support for sufferers and their families.
Dementia affects 10 million in China and up to 50 million worldwide, of which around 35 million sufferers are undiagnosed. Dementia causes deterioration in ...
Epilepsy in a dish: Stem cell research reveals clues to disease's origins and possible treatment
2013-07-25
ANN ARBOR, Mich. — A new stem cell-based approach to studying epilepsy has yielded a surprising discovery about what causes one form of the disease, and may help in the search for better medicines to treat all kinds of seizure disorders.
The findings, reported by a team of scientists from the University of Michigan Medical School and colleagues, use a technique that could be called "epilepsy in a dish".
By turning skin cells of epilepsy patients into stem cells, and then turning those stem cells into neurons, or brain nerve cells, the team created a miniature testing ...