The kelp forests off Point Loma’s shores that once represented more than just a single species of interest worldwide may be taking a turn in a new direction as its main harvester packs up and moves out.
Previously, the kelp not only offered distinct near-shore diving experiences in a unique ecosystem home to a mixed bag of marine life, but they were also important to the greater California economy. Giant kelp is one of California’s most valuable living marine resources and the kelp forests in Point Loma provided 25,000 tons of kelp annually, making for a large percentage of California’s annual income.
This will all change as ISP Alginates Inc., previously known as Kelco, has closed and will no longer harvest kelp from the beds.
“We have shut down and will stop harvesting because it has become very difficult to keep up with permits, electricity and many other expenses,” said Dale Glantz, spokesman for ISP Alginates Inc. “We are unsure of how this will effect the economy in California, but I can say that we made a huge mark and ran a very important business.”
Kelp is an important food source for humans and animals around the world. Algin, a substance found in the cell walls of kelp, is an efficient thickening, stabilizing, suspending and gelling agent used in a wide range of food and industrial applications. It can be found in various desserts, gels, dairy products and canned foods. It is also used to emulsify salad dressings, to retain moisture, to improve the texture of bakery products and to stabilize beer foam.
In industrial applications, Algin is used for paper and welding-rod coatings, sizing and textile printing. In pharmaceuticals and cosmetics, it is used to make tablets, dental impressions, antacid formulations and facial creams and lotions.
Giant kelp was first harvested along the California coast during the early 1900s. Several harvesting companies operated from San Diego to Santa Barbara beginning in 1911 and primarily extracted Potash and Acetone from kelp to use in the manufacture of explosives during World War I.
In 1928, Philip R. Park Inc. of San Pedro, Calif. began harvesting kelp and adding it to livestock and poultry food. In 1929, Kelco Company of San Diego (now ISP Alginates Inc.) began harvesting and processing giant kelp for livestock feed and for Algin.
Today, giant kelp is harvested from Imperial Beach to Santa Cruz. Harvesting is now managed by the California Department of Fish and Game (DFG) under regulations adopted by the Fish and Game Commission. Regulations currently allow kelp to be cut no deeper than 4 feet beneath the surface, although the surface canopy can be harvested several times each year without damaging kelp beds.
However, the constant grazing of Opaleye and Halfmoon can damage kelp forests when the fish are present in large numbers, especially when conditions are unfavorable for kelp growth. Invertebrates such as sea urchins, amphipods, isopods and crabs also graze on kelp.
Additionally, intensive fishing for California Sheephead, California Spiny Lobster and Abalone has significantly altered population dynamics in kelp forests. The sea urchin populations increased exponentially in some areas and overgrazed the kelp, creating areas known as “urchin barrens.”
Human activities also influence the health and distribution of kelp beds. Sedimentation of the rocky bottom can hinder kelp growth and even bury young plants, preventing development and reproduction. Pollution also affects kelp forests. Industrial and domestic wastewater discharges carry toxins, such as pesticides and heavy metals, which can accumulate in near shore sediments.
“In the 1950s and 1960s, once-productive kelp forests off Point Loma began to deteriorate,” said Ed Parnell, project scientist and kelp specialist at the Scripps Institution of Oceanography. “This was attributed to biological and physical factors related primarily to human activities such as sewage being dumped into the bay at the south end of Point Loma.”
In 1963, the Scripps Institution of Oceanography and Kelco Company began to develop techniques to protect and restore kelp forests off San Diego shores. Sea urchin control was achieved by spreading lime on urchins while kelp was transplanted. Later experimentation between 1991 and 1992 involved feeding urchins along a front to discourage feeding on attached plants.
“Things changed for the better and the bay was also deepened by 100 meters so conditions improved, but there is still sediments such as copper in the water that inhibits growth and the LA-5 dredge disposal sight may be contaminating waters,” said Parnell. “It’s a guessing game in the kelp beds. I mean, urchins may return like a plague of locust on the march, disease may attack, big storms or a serious El Nião may cause warm water and the beds could be in trouble, but for now, we enjoy them and the rich beauty they offer.”
As of late, Point Loma kelp bed growth is near historic highs in areas where it has chronically been a problem. Since 1999, water temperatures have been cool enough for major growth and conditions in the water are satisfying the kelp.
It is unknown whether another company will take ISP Alginates Inc.’s place in the kelp harvesting business, so the beds may be used only for aesthetic pleasures and oceanic study in the future. This could cause more kelp to build up on beaches.
“What a perfect business we were in and what a great mark we made on the economy, but like every good thing, it has come to an end and we’ll have to wait and see what the future holds for the kelp beds we studied and grew so fond of,” Glantz said.
To view life in the kelp beds, tune in to the live Scripps Institution of Oceanography Birch Aquarium KelpCam at www.aquarium.ucsd.edu on Tuesdays and Thursdays at 12:30 p.m. and Sundays at 10:30 a.m. to watch divers feed the fish and answer audience questions. Send questions via email and divers will try to answer them live during the next show.