December 30, 2013
Marine Mammal Diversity Can Be Monitored Accurately With DNA
Lee Rannals for redOrbit.com - Your Universe Online
Researchers have determined that DNA barcoding could be useful in accurately monitoring marine mammal biodiversity.
Up to now, scientists have had a difficult time monitoring marine mammal biodiversity. Some species can be easily observed, while others are more difficult because of their scarcity or their discrete behavior. Researchers collaborated to determine whether or not DNA barcoding could be useful for monitoring this type of biodiversity, concluding that it could be a useful method in conjunction with a stranding network.
The presence of marine mammals is thought to reflect the health of a place, while the disappearance or displacement of the animals shows negative environmental changes.
One solution to monitor marine species is based on the organization of stranding networks -- listing and recording marine mammal strandings. However, scientists wrote in a special edition of the open access journal Zookeys about how DNA barcoding could also help monitor these creatures.
A routine use of DNA barcoding to monitor marine mammal biodiversity could increase a scientist’s ability to detect impacts that global climate change might have on these animals’ environments. Understanding these factors is necessary to take appropriate measures to try and conserve marine biodiversity.
The Centre de Recherche sur les Mammifères Marins (CRMM) in France created the French marine mammal stranding recording program at the beginning of the 1970s. This program consists of about 260 field correspondents, including members of several organizations as well as volunteers.
The network found that an average of 150 animals are stranded each year in a region located at the northwest of France. This number represents 14 species of cetaceans and five species of pinnipeds, including bottlenose dolphins, harbour porpoises, minke whales and fin whales. The strandings have even included deep-diving or rare species like arctic seals.
“In this study, our aim was to determine the potential contribution of DNA barcoding to the monitoring of marine mammal biodiversity as performed by the stranding network,” the team wrote in the journal.
The team said they sequenced the DNA of 89 animals of 15 different species. All of the species were unambiguously discriminated on the basis of their mitochondrial cox1 gene, except for members of the Delphininae.
“With again [sic] the exception of the Delphininae, this was successful using the BOLD identification engine. For samples of the Delphininae, we sequenced a portion of the mitochondrial control region (MCR), and using a non-metric multidimentional scaling plot and posterior probability calculations we were able to determine putatively each species,” the team wrote. “We then showed, in the case of the harbour porpoise, that cox1 polymorphisms, although being lower than MCR ones, could also be used to assess intraspecific variability.
“All these results show that the use of DNA barcoding in conjunction with a stranding network could clearly increase the accuracy of the monitoring of marine mammal biodiversity,” the team concluded.