Increasing temperatures affect the abundance of breeding grey whales in Mexican coastal lagoons

durch Mariana Hill

Mittwoch 23.07.2025, 13:15 → 14:30 Europe/Berlin

8A-002 - Hörsaal Ostufer / Lecture Hall East (GEOMAR - Standort Ostufer / GEOMAR - East Shore)

Abstract

Grey whales (Eschrichtius robustus) migrate from their summer feeding grounds in the northern Bering and Chukchi Sea to the warm waters off Baja California Sur in Mexico. They nurse their calves in coastal lagoons from January to March. Their habitat range has been considered to be temperature-restricted, limited southwards by the 21°C isobar. In this study, we used Generalised Linear Models to assess the impact of environmental variability, particularly temperature, on the abundance of grey whales in the Magdalena Bay Complex.

We observed a significant impact of temperature on the occurrence of mother with calf pairs but no impact on single whales. We also observed a life-stage segregation in the lagoons, with mothers with calf showing a preference for the northernmost lagoon and single whales being more abundant in the south. The life-cycle and reproduction-cycles of grey whale aggregations off Mexico, as well as their different responses to increasing temperatures, might impact the local communities that depend on whale tourism as their source of income.