Seasonal sediment load, light attenuation and eel grass coverage in San Diego Bay

Eel grass (Zostera marina) beds in San Diego Bay are a protected habitat and artificial planting of beds is often accepted as mitigation for environmental disruption. The beds reduce sediment erosion, serve as a nursery for young fish and benthic organisms, and hence attract larger foragers. Which environmental parameters control the growth and distribution of eel grass, and under what conditions, is still uncertain. Though submarine light levels are felt to be the dominant control, individuals of a given species may have different light requirements when growing in different habitats of the same estuary and may require more light as variability in the available light increases. Extensive, independent surveys of water quality parameters (such as transmissivity, chlorophyll, total suspended solids and temperature) collected by NRaD, and surveys of bottom depth and eel grass coverage conducted by Southwest Division were combined to examine light attenuation as a determinant in eel grass success.