For today’s episode of Research Thursday, Andrew and I wanted to higlight a study examining the population and genetic structure of La Plata River Dolphins (Pontoporia blainvelli) in the southwest Atlantic Ocean. As one of the rarest and most vulnerable dolphin species, it’s critical to their future existence that scientists and policy makers have an accurate depiction of gene flow within the species.
A study published by a team of Brazilian researchers entitled “Population Structure of the Endangered Franciscana Dolphin (Pontoporia blainvelli): Reassessing Management Units” compared the actual genetic makeup and distribution of the species to found proposed regional “Franciscana Management Areas” (FMAs). These FMAs are geographic regions proposed by previous research as biologically and ecologically-relevant zones that should be protected along the coast of Brazil in order to lessen mortality of these river dolphins. Since La Plata River Dolphins are typically coastal mammals that inhabit relatively shallow and turbid waters, they’re highly susceptible to getting entangled in fishing gear and being affected by water pollution. Though the afore-mentioned FMAs were originally described based on scientific data, the new technologies researchers have at their disposal are better equipped to examine genetic data than they were just ten years ago.
After examining biological material of 162 Franciscana dolphins throughout their range, the researchers discovered that the species has at least two genetically-distinct populations: one restricted to the northern portion of the species’ range and one to the southern portion. Additionally, the authors found evidence for additional variations within each population. They also noted that the northern populations remain the least studied and potentially the most threatened group of individuals within the species. Not only should policy makers re-evaluate the number and borders of the previous FMAs based on this new data, they should also consider greatly increasing monitoring efforts in the northern populations.
Enjoy the Podcast!