Contrasting effects of the El Nino 2015-16 event on coral reefs from the central pacific coast of Mexico
Por:
Nava, Hector, Lopez, Norma, Ramirez-Garcia, Pedro, Garibay-Valladolid, Elizabeth
Publicada:
1 abr 2021
Resumen:
Coral reefs are highly diverse and productive ecosystems, and certain
oceanographic processes, such as El Nino, have resulted in severe coral
bleaching and mortality of reef-building corals and to the global
decline of the area covered by coral reefs. Here, we report the response
of corals and both green and red filamentous and coralline algae from
the central Mexican Pacific coast to the 2015-16 El Nino event. Sea
surface temperature (SST) was recorded in the area between june 2012 and
December 2018. Additionally, SST, DHW and the Oceanic El Nino Index
(ONI) provided by NOAA for the El Nino 3 region during the same period
were considered. Relative cover (%) of healthy, pale, bleached and dead
corals, coral rubble, filamentous algae, rocks, and sand were recorded
at five reefs during 2010, 2015, and 2018. Between April 2015 and April
2016, the SST was warmer than average, and the ONI showed temperature
anomalies near 3, indicating a strong El Nino event. The response of
corals varied among reefs and years. No relevant changes in substrata
cover were recorded at two reefs through the years, but extensive coral
bleaching occurred at the other reefs in June 2015, with dramatic coral
mortality as a consequence. An inability to recover and the resulting
dominance of filamentous algae over dead corals was evident at two reefs
in January 2018. Multivariate analysis based on the cover of substrata
and the comparison with previous studies suggested that the response of
the coral reefs was not related to the previous state of conservation or
the level of anthropogenic impact at each reef. The causes of such
thermal resistance are uncertain; nonetheless, it has a high potential
to cope with future El Nino impacts.
Filiaciones:
Nava, Hector:
Univ Michoacana, Inst Invest Recursos Nat, Lab Biodiversidad Marina, Av San Juanito Itecuaro S-N, Morelia 325557, Michoacan, Mexico
Lopez, Norma:
Univ Nacl Autonoma Mexico, Escuela Nacl Estudios Super Morelia, Unidad Multidisciplinaria Docencia & Invest Zihua, Morelia, Michoacan, Mexico
Ramirez-Garcia, Pedro:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Bot, Circuito Exterior S-N, Ciudad De Mexico, Mexico
Garibay-Valladolid, Elizabeth:
Univ Michoacana, Inst Invest Recursos Nat, Lab Biodiversidad Marina, Av San Juanito Itecuaro S-N, Morelia 325557, Michoacan, Mexico
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