New! Sign up for our free email newsletter.
Science News
from research organizations

Will warm-water events in the Gulf of California reduce seabird populations?

Date:
April 25, 2018
Source:
American Ornithological Society Publications Office
Summary:
Oceanic warm-water events in the Gulf of California have increased in frequency during the last three decades, passing from a historic mean of one or two warm anomalies per decade to five events in the 2007-2016 period. This can lead to massive failures in seabird nesting, as anomalously warm waters accumulate in the ocean's surface, preventing the upwelling of colder, nutrient-rich waters from the ocean bottom, which in turn deprives seabirds of their food.
Share:
FULL STORY

Oceanic warm-water events in the Gulf of California have increased in frequency during the last three decades, passing from a historic mean of one or two warm anomalies per decade to five events in the 2007-2016 period. This can lead to massive failures in seabird nesting, as anomalously warm waters accumulate in the ocean's surface, preventing the upwelling of colder, nutrient-rich waters from the ocean bottom, which in turn deprives seabirds of their food.

A recent study by Enriqueta Velarde from the University of Veracruz and Exequiel Ezcurra from the University of California Riverside, published in The Condor: Ornithological Applications, analyzed four decades of nesting dynamics of the threatened Heermann's Gull (Larus heermanni), and modeled population growth under normal and high sea-surface temperature conditions.

Heermann's Gulls exhibit the main characteristics of seabirds. They can live for decades, but take many years to reach breeding age, and produce few young. These traits allow their populations to resist oceanographic anomalies of up to one event every five years, but population size may decline rapidly if the frequency of warm-phase anomalies is over two per decade. Under normal conditions, predicted population growth is around 4%, with production of fledglings contributing to the population increase. Under anomalous warm-water conditions, population growth drops to -15% and adult survival becomes the key condition for the survival of the species. Simulations project a rapid population decline if warm anomalies maintain the high frequencies they have shown during the last decade.

These results underscore the need to understand the dynamics of warming ocean waters under current large-scale environmental change, as well as the importance of following the demographic dynamics of seabirds as indicators of oceanic conditions. Monitoring seabird populations may provide us with warning signals about the health and the future of our marine ecosystems.


Story Source:

Materials provided by American Ornithological Society Publications Office. Note: Content may be edited for style and length.


Journal Reference:

  1. Enriqueta Velarde, Exequiel Ezcurra. Are seabirds' life history traits maladaptive under present oceanographic variability? The case of Heermann's Gull (Larus heermanni). The Condor, 2018; 120 (2): 388 DOI: 10.1650/CONDOR-17-5.1

Cite This Page:

American Ornithological Society Publications Office. "Will warm-water events in the Gulf of California reduce seabird populations?." ScienceDaily. ScienceDaily, 25 April 2018. <www.sciencedaily.com/releases/2018/04/180425162018.htm>.
American Ornithological Society Publications Office. (2018, April 25). Will warm-water events in the Gulf of California reduce seabird populations?. ScienceDaily. Retrieved June 16, 2024 from www.sciencedaily.com/releases/2018/04/180425162018.htm
American Ornithological Society Publications Office. "Will warm-water events in the Gulf of California reduce seabird populations?." ScienceDaily. www.sciencedaily.com/releases/2018/04/180425162018.htm (accessed June 16, 2024).

Explore More

from ScienceDaily

RELATED STORIES