Centuries of Whaling Data Highlight Likely Climate Change Effect
Published:14 May2023 Source:University of Auckland
Southern right whales adjusted their foraging grounds over the past 30 years as climate change altered where prey could be found, according to a University of Auckland, Waipapa Taumata Rau scientist.the whales increased their use of mid-latitude foraging grounds in the south Atlantic and southwest Indian oceans in the late summer and autumn, according to Carroll and dozens of collaborators including lead author Solène Derville, of Oregon State University.
The whales also slightly increased their use of high latitude foraging grounds in the southwest Pacific, according to the article, published in the journal PNAS.Southern right whales, or Tohorā, live south of the equator, eating krill and copepods, which are small crustaceans. Chemical analysis of skin samples revealed the whales' feeding patterns in recent decades. The main source of historic data was the American whaling fleet's detailed records of where and what species were observed and killed in the Southern Hemisphere from the 18th to the early 20th century.
Tohorā were hunted to near extinction, with global numbers falling to as low as 500. By 2009, an estimated 2,200 of the creatures were in New Zealand waters, moving between the sub-Antarctic Auckland Islands (Maungahuka) and Campbell Island (Motu Ihupuku), and occasionally around mainland New Zealand including Stewart Island (Rakiura).