UC Toxics News: Summer 2001
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Surfgrass Saviors: Harnessing Ecotechnology to Conserve an Important Marine Plant by Peter Taylor Reprinted with permission from the Spring 2000 issue of Coastal Discovery Journal of the Marine Science Institute at UC Santa Barbara Editor's Note: This research was funded in part by the TSR&TP

 

 

 

 

 

 

Along the coastline of the Santa Barbara Channel grow beds of surfgrass, a flowering plant that lives underwater to depths of 20 feet, offering food and shelter for countless invertebrates and fish. But surfgrass beds are threatened by pollution, dredging, and other human activity. Damage to these plants could have wide-ranging effects on the Santa Barbara region’s ocean ecosystem.

Surfgrass seedling

The complex life cycle and stringent requirements of surfgrass have so far defied restoration efforts. Previous attempts to restore surfgrass relied on transplanting mature individuals to a new location. According to Sally Holbrook, a UCSB professor of biology affiliated with the Marine Science Institute, adult surfgrass, however, grows firmly attached to rock (all the better to withstand vigorous water movements), and it is very difficult to successfully reattach large plants in the surf zone.

Instead, Holbrook and colleague Dan Reed, a research biologist at MSI, have begun to examine the surfgrass life cycle, seeking new possibilities for helping the species to thrive. "We’re asking, Where are the bottlenecks and what are the options?" said Holbrook.

Surfgrass plants start out as large, nutritive seeds that are produced just once each year and that often fall prey to crabs, isopods, and fish. Water movements transport the seeds until they become entangled in bushy algae, which act as hosts for a year as the seeds sprout and grow. Finally, the rhizomes grow big enough to attach themselves directly to rocks, and the hosts no longer are needed. Normally, plenty of surfgrass seeds are produced, but huge numbers die during the initial period of drifting and early growth. This phase represents the major bottleneck.

"We want to accelerate that stage in order to decrease mortality," said Holbrook. Reed and Holbrook are now developing an ecotechnological approach for surfgrass restoration. They gather seed–producing structures from wild–growing plants, bring them into the lab for germination, and then place the new plants back into the wild, thus greatly reducing losses to predators. The scientists are also experimenting with using braided nylon netting as a artificial host, rather than algae. This process overcomes the problem of high mortality during the seed stage and also sidesteps the issue of whether the host algae are even present in the restoration area.

UCSB researchers have also discovered important genetic information for surfgrass restoration. Previously it was believed that each bed consists of identical clones. Genetic tests showed that, in fact, the beds comprise complicated mosaics of different individuals and clones. Moreover, the genetics vary at a regional scale. "So, for example, you might not want to use seeds from Point Conception down here near Santa Barbara," said Holbrook.

Reed and Holbrook hope to find a way to accelerate rhizome growth to facilitate practical methods of surfgrass restoration. One potential solution is to devise new ecotechnology such as "host" mats infused with as-yet-unidentified growth hormones. Although the researchers already have made substantial progress, effective surfgrass conservation will require significant interdisciplinary work involving plant physiologists, ecologists, geneticists, and fluid dynamics experts. Holbrook and Reed believe that the proposed Ecotechnology Center at UC Santa Barbara's Marine Science Institute could nurture the needed breakthroughs.

All photos by Scott Bull

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