Climate change; How Whales Change Climate

Climate change; how Whales change climate. “One of the most exciting scientific findings of the past half century has been the discovery of widespread TROPHIC CASCADES…” A trophic cascade is an ecological process that starts at the top of the food chain and cascades down the trophic levels to affect all life. Trophic cascades occur when predators in a food web suppress the abundance or alter the behaviour of their prey; this releases the next lower trophic level from predation (or herbivory if the intermediate trophic level is a herbivore). Whales swimming. Whales eat fish and krill. Some misinformed non-ecologists suggested that killing whales would boost the krill and fish population. However, as the great whales declined, so did the krill and fish populations. This supposed counter-intuitive result is easily explained when the entire system and the whale’s role in it is considered: how it feeds and how its feeding behaviour affects the entire ecosystem and its supporting life. Whales feed in the dark depths of the ocean, then return to the photic zone at the surface, where there is enough light for photosynthesis to occur. Whales then release fecal plumes (of poo; called poo-namies in the video). Rich in nutrients (such as iron and nitrogen) and often scarce in surface waters,