Botanists study restoration of rare wetlands

Dan Larkin (left) records data in a large pool within a 20-acre salt marsh restoration site at Tijuana Estuary in California, just north of the US-Mexico Border. His study was part of his dissertation on the importance of topographic heterogeneity to the restoration of ecosystems services.

Among the many services that wetlands perform, one of them is feeding hungry fish.

In sunny southern California, nutrients borne on high tides turn salt marshes into nurseries that grow algae, algae-eating invertebrates and invertebrate-eating fish.

Dan Larkin (Botany PhD, 2006) and Professor Joy Zedler reported in the journalEcological Engineering that restoration of these rare wetlands (reduced to <5% of their historical area) quickly provided vital support for coastal food webs.

Within weeks, pools that were newly dug by Larkin were rapidly colonized by highly mobile, opportunistic invertebrates — the "weeds" of the invertebrate world.

While flat salt marsh surfaces drained at low tide, the pools held water, making them hotspots for algae that fed the aquatic invertebrates that fish depend upon.  By restoring "messy" marsh surfaces with shallow pools, practitioners can create oases that attract and support native fish.