How Whales Change Climate

Whales are magnificent giants living within the depths of the ocean. Although most people do not see them on a daily basis they are extremely important creatures that do a lot to shape our world. They are another major keystone predator and also have a major effect on trophic cascades (just like the wolves in the last blog post). Many groups of people take whales for granted and believe that killing them for food, or oil is not a problem. It has actually been ingrained in certain cultures to accept that killing whales is a beneficial thing for the environment. Whales feed on fish and krill and when the number of whales began to decrease due to humans catching and killing them, something interesting happened. The number of fish and krill also decreased. This was the opposite of what we assumed would happen. We believed that with less whales feeding on fish and krill that we would see an increase in number. However this was not the case because whales are also responsible for sustaining the entire living ecosystem of the ocean. Whales act as biologic pumps feeding in the dark parts of the ocean and then rising up to the surface pulling nutrients. The surface of the ocean is known as the photic zone and this is where photosynthesis occurs. The whales create fecal plumes which are rich in iron and nitrogen which fertilize plants in the photic zone. Their plunges up and down through the ocean also is responsible for stirring the plankton around allowing it to photosynthesize and reproduce more. This vertical mixing of water is crucial for ocean life and has been recognized as having the same effect as the worlds wind, wave and tide power combined! This means that more whales means more fish and plankton... not less! Plant plankton absorbs carbon dioxide out of the air and then sinks to the ocean floor where it then remains for thousands of years. Therefore with more whales, we have more carbon dioxide absorbing plankton in the oceans acting as a carbon sink and pulling harmful CO2 out of the atmosphere.

This means that whales can actually affect climate change! It is predicted that historically whales could have been responsible for removing tens of millions of tons of carbon from the atmosphere every year. So could whales be an answer to our climate crisis today? Maybe! They could at least help by drastically increasing the removal of carbon dioxide from our atmosphere if their population numbers are allowed to rebound, thereby increasing the oceans ability to act as a sink for CO2.