Scientists from Australia and New Zealand found that migratory patterns of southern right whales are "etched" in the species' DNA, revealing new information that could help contribute valuable data in saving the endangered ocean creatures.
Constancy in migratory targets is an essential factor of linkage in marine and avian species. Southern right whales (Eubalaena australis) have migratory connections, ranging thousands of kilometers from covered coastal wintering areas to seaward feeding locations.
In the new study, researchers led by Dr Emma Carroll from Macquarie University in Australia and University of St. Andrews in UK, assessed the role of migratory culture and habitats acquired from maternal influences in the population of southern right whales in New Zealand and Australia.
The authors collected small skin samples from the whales via a biopsy tool made of stainless steel. The said tool resembles a dart and was shot from an altered veterinary capture rifle or fired via a crossbow.
The researchers then analyzed the one-of-a-kind DNA markers on each whale, which enabled them to form an atlas of population structure and relationship between species. They also tested micro-chemical indicators, which exposed the species' feeding ground choices.
The study demonstrated how young whales obtained their migration preferences from their parents, causing them to travel in the same direction to get to their chosen destination when they mature.
The study also showed that migratory culture had an impact on genetic patterns seen in summer feeding grounds and winter calving areas. As per analysis, the whales preferred to go to Antarctic waters during the summer for feeding.
"When whales that show fidelity to a particular migratory destination are extirpated, the 'memory' of that migratory destination is also lost," the authors wrote. This effect is worsened when there is deficiency across the migratory network just like in the case of whaling, which is the hunting of whales for meat, scientific research and other uses.
Despite whaling, evidence of genetic combinations determined by the researchers even if there is lack of flexibility in migratory fidelity suggests that destination where the whales migrated in the past would be recolonized as species recoup from whaling.
The study was published in the journal Scientific Reports on Monday, Nov. 9.