Blue whale song frequencies are observed falling worldwide

node

Analysis of acoustic recordings reaching back to the 1960s finds that blue whale song is being sung at steadily lower frequencies. The best-documented song type, off California, is reported as being sung 31 percent lower than in the 1960s, and seven of the ten known song types for which data exist are shifting downward, at different rates. Several explanations were floated in the 2009 paper that described it - changes in ocean acidity, whaling-driven shifts in average body size and population density, rising ambient noise - and none satisfied the authors. It is one of the few well-measured, long-running, genuinely unexplained observations in large-whale biology.

A node is not a place. Drawing it on a map would assert something about the world that no stored fact supports.