Dear MARMAM recipients,
New open access paper in Frontiers in Marine Science:
Authors: Christina Blevins, Geraldine Busquets-Vass, Mario A. Pardo, Diane Gendron, Jeff Knut Jacobsen, Francisco Gómez-Díaz, Héctor Pérez-Puig, Christian Daniel Ortega-Ortiz, Gisela Heckel, Jorge Urbán R, Lorena Viloria-Gómora, Seth D. Newsome, published in Frontiers in Marine Science, section Marine Megafauna.

Title: “Sex-and age-specific migratory strategies of blue whales in the northeast Pacific Ocean”
Link: http://journal.frontiersin.org/article/10.3389/fmars.2022.944918/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Marine_Science&id=944918
Abstract: Migration is a complex behavior that has evolved in multiple taxonomic groups as a means of accessing productive foraging grounds and environmentally stable areas suitable for reproduction. For migratory whales that forage throughout the year because of their high energetic demands, changes in the abundance of prey in different areas along their migratory route(s) can have serious implications for individual fitness and population viability. Thus, identifying the regions these species use to forage and breed while evaluating their migratory plasticity at the individual level can provide key information for their management and conservation. Serial stable isotope analysis of whale baleen, a continuously growing but metabolically inert tissue, has proven useful in generating individual migratory and foraging records over several years prior to death. We measured carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope values along the length of baleen plates collected from thirteen blue whales of different sex and age classes, representing the largest collection analyzed to date in the northeast Pacific Ocean. Adult females exhibited relatively stable seasonal movements between temperate latitude foraging grounds and subtropical breeding grounds, although two skipped migration one year and subsequently moved to the same subtropical breeding ground near the Costa Rica Dome, potentially to give birth. Adult males exhibited two movement strategies with most remaining at temperate latitudes for 3-4 years before death, while two migrated to subtropical breeding grounds. In contrast, movement patterns in juveniles were erratic. These results are potentially driven by the energetic requirements during pregnancy and nursing in adult females, intra-specific competition among adult males, and inexperience in locating prey in juveniles. We also describe baleen δ¹⁵N patterns in recently weaned whales (<16.5m) that reflect switching from the consumption of milk to solid food (krill). In addition, baleen δ¹³C data suggest that weaned whales continue to use stored nutrients (blubber) acquired during the nursing period long after they are weaned. These results broaden our understanding of habitat selection in this species, highlight the importance of nursing for the critical period after weaning, and indicate that the Costa Rica Dome is an important calving region for this endangered population.

 

 

Sincerely,
Geraldine Busquets Vass

Research Scholar

University of New Mexico

Biology Deparment

Albuquerque, NM USA 87131

Researcher

Laboratory of Marine Macroecology

Center for Scientific Research and Higher Education at Ensenada, La Paz Unit (CICESE-ULP)

La Paz, BCS, MEX 23050