Eye on Nature: Undersea Forest Revives


By Ellen Girardeau Kempler


Kelp forest off Channel Islands, National Oceanic and Atmospheric Administration
Kelp forest off Channel Islands, National Oceanic and Atmospheric Administration

With “trees” and a canopy that shelters a colorful variety of species, Southern California’s version of a rainforest grows just off Laguna’s shore.  Environmental groups like Nancy Caruso’s Get Inspired (and many others) have helped restore giant kelp forests and beds.  From its holdfast (not a root) anchored to rocks on the ocean floor, this brown algae grows toward the surface. Balloon-shaped air bladders help lift kelp’s blades (leaves) and stipe (stem) toward the light.

Giant brown kelp grows faster than tropical bamboo: as many as two feet, or an average of 10-12 inches, per day, or up to 175 feet at full height. Because it absorbs nutrients from the seawater, not the ocean floor, it tends to thrive in turbulent spots with the most upwelling. Although large storms and waves often dislodge kelp and carry it onshore, it usually recovers quickly from these natural events.

Reaching their peak density and range about 20,000-7,500 years ago, kelp forests’ subsequent decline was caused by natural climate and ocean changes and accelerated in modern times by pollution, erosion, over-harvesting and ecological imbalance.  Giant kelp provides food and shelter for many species. Decomposing fronds, or detritus, feeds bottom dwellers such as rays.  Invertebrates such as sea cucumbers, brittlestars and sea urchins graze on the blades and live in the holdfast. Thousands of damselfish, garibaldi and other species dart alone and in schools through the kelp camouflage. Beneath the canopy, marine mammals such as California sea lions and harbor seals dive and play.

Although kelp provides fertilizer, nutritional supplements and alginate, an additive in everything from ice cream to toothpaste, Laguna’s status as a marine state reserve prevents harvesting here.  A visible symbol of our environmental progress, our thriving marine forests give us reason to celebrate Earth Day with a Kelpfest.

The former communications director of Laguna Art Museum and Laguna Canyon Foundation, Ellen Girardeau Kempler is founder and chief navigator of Laguna-based Gold Boat Journeys. She specializes in travel planning, writing, strategic marketing and social media training. Contact her at [email protected].

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