Every species, whether invasive or endemic, influences all of the other lifeforms around them. This especially true of animals near the top of the food chain who need to consume massive quantities of food to survive. As some of the largest animals to have ever lived, whales have a staggering effect on their environments. As you wait to see the best blue whale watching San Diego has to offer, here is a rundown of the role whales play in their ecosystems.
Generally speaking, the larger the animal, the more food is needed to stay alive. Because whales are so big, they need to consume thousands of pounds of food a day. A blue whale can eat about four tons of tiny crustaceans called krill per day. Krill feed on tiny algae species called phytoplankton. Phytoplankton are responsible for taking tons of carbon out of the atmosphere, slowing the rate of manmade climate change. Through this process, in which predators at the top of the food chain affect organisms at the bottom, whales significantly help to alleviate climate change. Ecologists call this pattern of influence “trophic cascades.”
Whales belong to an order called cetaceans, which have many different lifestyles. Some species that are technically not considered whales, such as orcas, are powerful apex predators. Orcas reduce sea lion populations, and this allows small fish species to flourish. Dolphins consume large numbers of fish. As each species has its own role to play, the place whales and their cousins have in the ocean ecology is almost infinitely complex. So, why should we protect aquatic ecosystems if we don’t fully understand them? Because we can’t afford to let the oceans suffer.
When food passes through the body of large baleen whales, it becomes digested and excreted out the other end. Naturally, this matter falls to the bottom of the ocean and circulates the upper levels of the ocean. Interestingly, the iron and nitrogen contained in whale poo is essential for phytoplankton to grow. As this, in turn, feeds krill and many other creatures, it is vitally important that whales continue to consume food and produce waste.
The role that whales have on earth isn’t just limited to the ocean. Like tigers and wolves on land, whales are umbrella species, or species that lawmakers and conservationists think about when making conservation decisions. Whales are also excellent indicators of overall ocean health, as large food supplies are necessary to sustain them. Because they are so charismatic and visible, people are often extra willing to provide funds to protect whales. This is great for all the other aquatic species who depend on dedicated humans to protect them from pollution and overexploitation.
When visiting San Diego, the ocean is an attraction you can’t miss. Try taking the family to a tide pool ecosystem or go on a whale watching tour. The seas are perhaps the earth’s greatest natural resource. The more you and your family learn about them, the better future generations can help to preserve natural ecosystems and the animals that inhabit them.