Algal blooms created ancient whale graveyard.

Andrew Robbertz

Author: Sarah Zielinski
Published: February 28, 2014
Article Link: https: //www.sciencenews.org/blog/wild-things/algal-blooms-created-ancient-whale-graveyard

Summary: In 2010, in the barren Atacama Desert of northern Chile, Came across a curious site while expanding a highway through the desert. In the rock were buried the fossils of many whales and other marine mammals. Researchers were able to remove some of the fossils and take 3D scans of others. The scans, which kept the orientation of the bones allowed the researchers to reason the cause of their death. The orientation suggested that the mammals had been washed onto a beach, where they were rapidly buried. They believed they had been washed ashore between 6 and 9 million years ago. They believed they had died to a similar cause to many whales around Cape Cod, Massachusetts in 1987 and 1988. These waled were killed from eating Atlantic mackerel that had been contaminated with a neurotoxin produced by an algal bloom. A high iron runoff from the Andes Mountains often causes an algal bloom on the west coast of South America. On the beach the skeletons would be preserved as there were no wakes crashing on them and no predators to pick them apart.

Relevance: This article connects to our unit on Microbes, and the section that focused on algae. The algae blooms that were caused 9 million years ago, and causing mass deaths is continuing today with the death of the wales off of Cape Cod. The algae that killed the whales produced a neurotoxin that was harmless to the smaller organisms that ate the algae, but because of biomagnification the concentration of the toxin became denser, and was in a high enough concentration to kill the wales. A similar thing is happening today in the Gulf of Mexico. Runoff from farms along the Mississippi river dump into the Gulf of Mexico, causing algal bloom. The algae create a dead zone, where the water is deprived of oxygen. This is killing many species of fish as well as destroying coral reefs.