Trickle down isn’t just a theory in economics. Deep sea creatures depended on it for their survival. When an asteroid that hit Mexico’s Yucatan Peninsula obliterated the dinosaurs and life on earth 65 million years ago, the creatures that lived deep in the oceans survived on bacteria and dead algae that trickled down into the ocean floor. After all, they were dependent on the world above them to provide sustenance. Up until this point, researchers assumed that the asteroid cut off all food supplies, including those in the oceans.
Our results show that despite a wave of massive and virtually instantaneous extinctions among the plankton, some types of photosynthesizing organisms, such as algae and bacteria, were living in the aftermath of the asteroid strike. This provided a slow trickle of food for organisms living near the ocean floor, which enabled them to survive the mass extinction, answering one of the outstanding questions that still remained regarding this period in history.
The team analyzed new data taken from drilling cores from the sea floor of South Atlantic Ocean. They studied the chemical composition of the fossilized shells of sea surface and sea floor organisms from that time period. Researchers used isotopes of carbon and oxygen, the rare Carbon 13 and Oxygen 18 as markers of the time period and that these heavy elements made their way to the ocean floor. These microorganisms filtered from above provided a meager source of nutrients. The scientists found that though the flow of nutrients would have been disrupted after the asteroid hit, there was just enough food to sustain deep sea life.
Even so, it took almost two-million years before the deep sea food supply was fully restored as new species evolved to occupy ecological niches vacated by extinct forms.