Featured Image Credit: Franco Banfi
By Eva Gruber
Climate change is a serious threat to our planet – perhaps the greatest threat mankind has ever faced. It stems from our own activity, dumping greenhouse gases into the atmosphere through the burning of fossil fuels, as well as through animal agriculture and deforestation. To think that these massive changes to our planets very structure could not impact it, is incredibly naïve.
As climate change accelerates, ecosystems are forced to deal with the consequences. The oceans are not immune to the threats of climate change, and in fact may be more sensitive than the land. One of the threats is ocean warming. By increasing the temperature of oceanic ecosystems, we are changing entire chemical and physical processes that have been stable for millions of years.
In a healthy oceanic ecosystem, layers of shallow, warm, sunlit waters mix with deep, cold, nutrient-dense waters at certain areas which are influenced by the topography of the ocean floor. These areas are known as upwelling zones, and they are incredibly productive – think Galapagos Islands, the coast of California, and the South African Cape.
These areas are so productive because this mixing of deep-sea nutrients with sunlit water encourages the growth of phytoplankton – the base of the marine food web. And all marine life up the food web benefits.
However, with increasing ocean temperatures, this mixing slows down as the layers of the ocean become stratified, and immobile. This is where the heroes of the story come in: marine mammals. As they dive from the surface to the depths of the ocean, and then return to the surface, they mix water in much the same way that a pump does. Their movement might enhance the mixing of ocean layers, and enhance the growth of phytoplankton.
Unfortunately, the populations of marine mammals around the world are not what they once used to be. Historical numbers account for a bounty of marine mammals, which hunters exploited for various reasons. Whales were targeted for their meat and for their oil, which fueled lamps in cities around the world, and many pinnipeds were hunted for their pelts.
While the whalers and seal hunters of the world did not understand ecology and the important role that many marine mammals play in ocean ecosystems, we know far more now than they did back then and do not have the excuse of ignorance. While many still deny climate change is real – the consequence of oil companies lobbying for ways to deceive the public – climate change continues to have increasing effects on our planet, and very soon, humans will no longer be immune from the ver obvious consequences.
By taking measures to further protect our marine mammals, which might help mitigate the effects of climate change, we might stand a better chance at saving our environment before it is too late. While there is still much to be studied and understood about the way ocean ecosystems work, for now we can be sure that marine mammals are crucial players in the puzzle of natural history and human-driven climate-change. That should be more than enough reason to stop whaling, to enact more Marine Protected Areas, and to make small sacrifices in our own lives so that we minimize our contributions to climate change.