Particulate accumulated matter as an indicator of coastal benthic habitat condition.

Eutrophication adversely affects coastal areas, but most indicators of eutrophication demonstrate temporal or large-scale changes in eutrophication. These usually cannot be used in local actions, such as restoration or conservation. Eutrophication also results in increased accumulation of particulate matter and here we assess the usefulness of particulate accumulated matter (PAM) as an indicator for marine habitat condition in the northern Baltic Sea. We use > 50 000 observations of PAM, to spatially model the accumulation of PAM at shallow benthic substrates, and subsequently demonstrate the use of PAM as an indicator for benthic habitat quality. Predictions show only 4.8% of the shallow marine area as not affected by PAM and the abundance of PAM negatively affected the occurrence of Fucus habitats. Estimates of amount of PAM can be used for determining areas that will benefit from restoration and nutrient abatement actions and for locating the most pristine areas in need of conservation action.