Macroalgal Beds

Four species of macroalgae—Ulva spp. Gracilaria pacifica, Fucus gardneri, and the introduced Sargassum muticum—are sufficient to create beds in the estuary; however, their distribution and extent is poorly known. Macroalgae provide a suitable food source for a variety of grazers, predominantly macroinvertebrates. Water birds use it to line their nests. The beach wrack produced by macroalgae is an important food source for invertebrates living in beaches, mudflats, and marshes: they in turn provide food for shorebirds and other species along the shore. There have been few reports of nuisance blooms of macroalgae in the bay, although this could change if turbidity decreases.

Intertidal algal beds are vulnerable to trampling and recreational harvesting as well as oil spills and dispersants. Because it is unclear whether additional macroalgal beds would be beneficial in the bay or that they are in short supply, and because it is difficult to distinguish algal beds that support ecosystem services from those that interfere with them, the Subtidal Goals Project recommends that additional research be performed and existing macroalgal beds protected.

To read more, download the macroalgal section of our report.




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