#mass mortality

[roosaurusrin]

Mass Mortality

This fossil, displayed at the Sternberg Museum in Kansas, is a plate holding dozens of crinoids. Having lived in communities, it only took a single, bad event to wipe this one out. 

[todropscience]

LARGEST BALEEN WHALE MASS STRANDING IN SOUTHERN CHILE RELATED TO TOXIC ALGAL BLOOM

In March 2015, by far the largest reported mass mortality of baleen whales took place in a gulf in Southern Chile. At that moment, researchers discovered 367 dead whales, from the sector of Gulf of Penas and Puerto Natales, in Magallanes region.  

In May the scientific journal PeerJ published the final study on the mass stranding event, most of them sei whale (Balaenoptera boreal), whale species which is endangered. According to the research, led by Vreni Häussermann, the event was related to the proliferation of toxic algae during the El Niño phenomenon.

While large mass mortality events are well known for toothed whales, they have been rare in baleen whales due to their less gregarious behavior. Although in most cases the cause of mortality has not been conclusively identified, some baleen whale mortality events have been linked to bio-oceanographic conditions 

According to the study if the frequency and magnitude of mass mortality events increase due to climate change this would have a significant impact on the local population and threaten the recovery of this endangered species, which in the Southern Hemisphere was reduced by whaling from about 100,000 to 24,000 individuals by 1980.

Photo: SERNAPESCA

Reference:  Häussermann et al. 2017. Largest baleen whale mass mortality during strong El Niño event is likely related to harmful toxic algal bloom. PeerJ

[todropscience]

LA NACRA SE MUERE EN EL MEDITERRÁNEO ESPAÑOL

Investigadoras españoles del IEO recientemente han revelado las elevadas tasas de mortalidad -de hasta un 100%- en la mayor parte del litoral mediterráneo, incluyendo las poblaciones de Andalucía, Murcia, Comunidad Valenciana e Islas Baleares, mientras que las poblaciones de las costas catalanas todavía persisten. Se han realizado censos científicos en 137 localidades registrando datos de más de 1.600 nacras en distintos hábitats y en un amplio rango de profundidad. 

La presencia del parásito protozoo del género Haplosporidium que infecta la glándula digestiva es probablemente la causa esta mortalidad. Sin embargo en la actualidad aún se desconoce cuál ha sido la vía de entrada de dicho patógeno. La nacra (Pinna nobilis) es un molusco endémico y protegido del Mediterráneo que se caracteriza por ser el bivalvo más longevo y de mayor tamaño de este mar.  Las elevadas tasas de mortalidad han llevado a la comunidad científica a repensar el estado de vulnerabilidad de la nacra, a "en situación crítica" la que está pendiente de publicación en orden ministerial española. 

Referencia (Acceso Abierto): Vázquez-Luis et al.,  2017. S.O.S. Pinna nobilis: A Mass Mortality Event in Western Mediterranean Sea. Front. Mar. Sci.

[algaeworldnews]

Scientists may have solved 2011’s mysterious marine die-off along the Pacific coast

Scientists may have solved 2011’s mysterious marine die-off along the Pacific coast

In August 2011, a sudden mass die-off of marine organisms off the coast of California, including sea stars, chitons and abalone, left scientists scratching their heads.

University of California Davis scientists first caught on to the strange event when they found thousands of purple sea urchins and other organisms dead in their laboratory tanks. The tanks were full of seawater that came straight…

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