BioBlog: Forest Under the Sea
By Julianne E. Steers, Marine Biologist


“Have you ever seen a forest without any birds, without any trees, without any bees?  Have you ever seen a forest under the sea?” –Banana Slug Band

Even on our sunny days, our coastal, temperate waters may appear encircled by a forbidding, often steely grey sea, although there are those rare, magical calm days when its surrounding seas take on an altogether more inviting hue.

A look just beneath the surface can reveal a wealth of hidden treasures.  Nowhere is this more so than in the great forests of kelp that are perfectly adapted to thrive in these tumultuous conditions.  In fact, these waters bring renewed supplies of nutrients to our grand algae.  Giant Kelp (Macrocystis pyrifera) crafts our kelp forests densely packed seaweeds up to 100ft high with an anchorage on the sea bed and blades that float.  Held upright by gas-filled bladders at the base of these leaflike blades, kelp fronds grow straight up to the surface, where they spread across the top of the water to form a dense canopy.  It provides one of the most biologically productive marine habitats creating a rich environment for thousands of other marine creatures.

Key to the forest’s survival, and the over 800 species it’s supports, is the ocean water quality.  Our sea is cyclical, at times stable, and undergoes ebbs and flows of temperatures and compositions throughout the year.  Spring and summer, the briny coast warms.  Fall instigates a cool spike, kicking off the reproductive cycle and making for a continued cool winter, optimal for growth.

Julianne Steers is a Marine Biologist and Director of Living Collections and Research at Ocean Institute. You can glide over the great kelp forests aboard one of our Whale Watches and Eco-Cruises, which are all guided by Ocean Institute scientists like Julianne.