The Costa Rica Dome - A Nursery For The Worlds Largest Animal

Blue Whales are the worlds largest baleen whale, the worlds largest mammal, the worlds largest animal, the worlds largest predator and experts believe largest living creature to ever breathe on our planet. Scientists and oceanographers are constantly carrying out research on them in attempt to assist in the survival of this magnificent creature.

There are nine distinct Blue Whale populations in the world. The Eastern North Pacific Blue Whale population estimated at a little over 2000 represents the largest remaining Blue Whale population on earth. They can be seen off the coast of California and they migrate from north to south and back again every year. Until recent times one of the greatest mysteries of the sea was where are these type of baleen whales born? The best way to protect them is to discover where they breed and learn what they will encounter during their migration.

In California, Blue Whales are often seen in pairs. Scientists attach tags to lead animals as they are suspected as females and they can track them during the winter migration south. These satellite tags lead researchers to the places where they give birth somewhere in the tropics. One such place of choice for the Eastern North Pacific Blue Whale is the Costa Rica Dome.

The Costa Rica Dome is a phenomenon of wind and currents. It is a thousand square kilometers of open ocean where cold water from the deep rises to just below the warm tropical surface. Wind and currents push the warm water aside to allow for the rising of  the nutrient rich cold water. The boundary between these temperatures represent the shape of a dome. Its position changes from year to year and is constantly moving. The combination of warm and cold water makes the perfect habitat for Blue Whales.

Cold water is often rich with nutrients with plankton and krill which makes up nearly all of the diet of the Blue Whale. It takes around one metric tonne of krill to fill a blue whales stomach and they can devour three and a half tonnes of these small shrimp-like crustaceans every day.

The Costa Rica Dome offers more than just food for these giants of the ocean. The tropical water acts like an aquatic crib for many of the young of other species of fish. In such an environment the combination of comfort and an abundant food supply lends itself to being an ideal nursery for Blue Whales.

It takes weeks for the Blue Whales to reach the Costa Rica Dome after leaving California waters. Pregnant females arrive at the end of their last trimester. After seven months the fetus of the Blue Whale is four meters long. Over the next few months the Baby Blue will grow two and a half centimeters each day.

Experts on Blue Whales suggest that these babies are born sometime in January. A birth of a Baby Blue Whale must happen very quickly just below the surface of the ocean. A new born whale would emerge back end first. Fast clotting of the whales blood inhibits bleeding as that would attract predators. Whales are mammals. They are warm-blooded, have lungs rather than gills and they breathe air. A baby must be able to swim to the surface just moments after birth.

Blue Whale infants are the largest babies in the history of life on earth. They nurse for about seven months nourishing its young with milk until they double in size.  Their milk is very rich and  is about forty percent fat. The calves drink nearly two hundred liters of milk and each gain over one hundred kilograms every day.

The time comes for the migration north and the mother will take her baby to the krill beds. The mother swims underneath allowing the baby to rest close to the surface. Blue Whales struggle to become adults and need ten years to reach full maturity.

During their migration north, they will swim from tranquility into peril. Some of the higher density areas that Blue Whales use and return through every summer to feed are intersecting with areas of increasing shipping traffic. This is the recipe for disaster for the whales. Ships strikes pose the biggest threats to the baby Blue Whales and the research from dedicated scientists offers the best hope for new shipping paths that will give whales the space they need.