Radio-tracking rafts of giant kelp: local production and regional transport

• Published in: Journal of experimental marine biology and ecology 1989-01, Vol.130 (3), p.237-251
• Main Authors: Harrold, Christopher, Lisin, Susan
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Biological and medical sciences; Drift kelp; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Macroalgal detritus; Macrocystis pyrifera; Marine; Methods and techniques (sampling, tagging, trapping, modelling...); Surface transport
• ISSN: 0022-0981; 1879-1697
• DOI: 10.1016/0022-0981(89)90166-4

Forests of giant kelp Macrocystis pyrifera (L.) C.A. Agardh are among the most productive communities on earth. Much of the annual production of kelp in central California is exported from the forests as large floating rafts. Since these rafts may float for days and perhaps weeks, they are capable of being transported long distances but the fate of this material remains largely unknown. Naturally occurring and artificially created M. pyrifera rafts were tagged with radiotransmitters near their point of origin along the shores of the Monterey Peninsula in Monterey County, California, on each of four seasonal tracking experiments. Their movements were followed by aircraft for 5–7 days and the transmitters were then recovered. 39 tagged kelp rafts were recovered within Monterey Bay and one transmitter was lost at sea. Most were recovered ashore. While surface currents in Monterey Bay flow to the north much of the year, the kelp rafts drifted before the prevailing northwest winds (i.e., to the southeast) in the spring, summer and autumn. Rafts tagged during the winter moved primarily toward the north. The regional deposition pattern of locally produced kelp rafts suggests that this material may be delivered to offshore benthic communities as large parcels which may play an important role as food and/or habitat.