Distribution of Macroinvertebrates Across a Tidal Gradient, Marin County, California

The distribution of macroinvertebrates across a tidal gradient is described froma study of invertebrate distribution across tidal marsh sub-habitats, a non-quantitative survey of epifauna on intertidal rocky substrate, and a few additional observations and records from China Camp State Park, Marin County, California. In the tidal marsh study, invertebrates were sampled from distinct sub-habitat types: high-order channels, low-order channels, vegetated marsh plain, and natural levees adjacent to channels. Invertebrates were collected using a variety of trapping methods to account for capture biases associated with any one method. All common invertebrate taxa were significantly more abundant in a particular sub-habitat, and within each trapping method a few species accounted for most of the biomass. On intertidal rocks, 79% of the taxa identified to species or genus were exotic, but a few native species were common.