Effective methods for assessing ecological quality in intertidal soft-sediment habitats

Impacts of anthropogenic pollution on marine ecosystems are being addressed by legislation to protect and restore coastal and transitional waters. A range of biological measures have been investigated for their ability to indicate anthropogenic disturbance in subtidal soft-sediment habitats, but little work to date has focussed in intertidal habitats. This study investigated the sensitivity of communities, individual taxa, diversity indices and biotic indices to nutrient and organic enrichment in intertidal soft-sediment habitats. Variation in macrofaunal communities was more strongly associated with anthropogenic stressors than with natural environmental variation. Two multimetric indices, M-AMBI and IQI, were more closely associated with nutrient and organic pollution than the AMBI and ITI indices. Intertidal monitoring based on existing monitoring tools offers a cost effective alternative to subtidal monitoring and has potential to form the basis for an ecosystem level approach.