April 26, 2016

So, what is the most important living thing in the ocean? Perhaps it is the magnificent blue whale? Blue whales are the largest living animals on Earth. The average blue whale reaches lengths of almost 100 feet, or 30 meters, and can weight up to 170 tons. In fact, they are the heaviest animal to ever live. These behemoths frequent the poles where they consume almost 8,000 pounds of food every day.

Killer Whale.

However, as impressive as they are, blue whales are not the most important creature in the sea.

Maybe it is the ocean’s apex predator, the killer whale?

Without any natural predators, killer whales are literally at the top of the heap. Even great white sharks can’t hold a candle to the predatory feats of the killer whale. Working in family groups, killer whales have been known to knock seals from floating ice, push grey whales to the point of exhaustion, and herd salmon toward dead ends for easy consumption. Killer whales are the largest member of the dolphin family. They came by their name honestly--they are killer of whales.

And yet, they are not the most important organism that inhabits the ocean.


What about king crab, oysters, mackerel, shrimp, or tuna? This bounty from the sea must surely be the most important? Combined, the harvest of these animals is a multimillion dollar industry that means work for millions of people worldwide in support of our desire for seafood.

The 2015 king crab season saw the harvest of more than 300,000 pounds of crab from the frigid waters of Alaska. At a consumer value of $13/pound, it’s surprising that neither these shellfish, or their equally valuable counterparts are not the most important animals in the sea.

So what is it? What organisms reign supreme as “The Most Important” in the ocean?


Yes, those tiny plants and animals that make up the basis of most marine food webs.

Plankton bloom.

They’re innocuous, floating under the radar of most ocean enthusiasts.

Plankton, from the Greek meaning “wanderer” are classified as zooplankton, the animals, and phytoplankton, the plants. Phytoplankton is considered a primary producer, generating massive volumes of oxygen and consuming carbon dioxide via the process of photosynthesis. Phytoplankton are the first step in most marine food webs as they are eaten by zooplankton such as: krill, copepods, various crustacean larvae, and baby fish. Zooplankton are consumed directly by crabs, oysters, shrimp and other commercially valuable shellfish and small fish such as anchovies. Those great blue whales rely solely on plankton to support their enormous appetites--some .5 million kilocalories/day to meet their dietary requirements. And when you connect the dots, Orcas, those killer of whales, wouldn’t have much to eat if plankton didn’t fuel the biomass they rely on.

So the next time you’re thinking about the pillars of the sea, the key organisms that make the ocean what it is, think small.

Think plankton.

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