DNA Metabarcoding Reveals Unexpected Predator-Prey-Microbial Dynamics in the Southern Right Whale (Eubalaena...

Area of Science:

• Marine Biology
• Ecology
• Microbiome Research

Background:

• Southern right whale (SRW) populations are recovering but show variable recovery rates linked to prey availability.
• Understanding SRW diet is crucial as foraging patterns shift from traditional krill-based grounds.
• The gut microbiome reflects diet and can indicate ecosystem changes.

Purpose of the Study:

• To characterize the diet and fecal microbiome of SRWs across different habitats.
• To investigate the relationship between SRW diet and gut bacterial composition.
• To assess the impact of changing prey availability on SRW trophic dynamics.

Main Methods:

• DNA metabarcoding was employed to analyze SRW diet and fecal samples.
• Samples were collected from calving/socializing grounds and a low-latitude foraging area.
• Statistical analyses correlated diet composition with fecal bacterial composition.

Main Results:

• SRW feeding is more opportunistic than previously assumed, with Decapoda frequently detected.
• Decapoda were more prevalent in the diet than euphausiids and copepods across all sampled locations.
• A significant correlation was found between diet and gut microbiome, with euphausiids strongly predicting bacterial variation.

Conclusions:

• SRW diet is broader and more diverse than previously documented.
• Findings establish a baseline for monitoring diet-gut microbiome interactions in SRWs.
• Results highlight the influence of climate-driven zooplankton shifts on this key Southern Ocean predator and its recovery.