Benthic kelp and invertebrate counts, California sheephead abundance, substrate rugosity data, and benthic temperatures from long-term kelp forest ecosystem monitoring sites at San Nicolas Island, California

Four data sets are included here to aid in assessing the influence of substrate complexity on kelp forest ecosystem stability. One data set consists of counts of a suite of kelps and benthic invertebrates on permanent band transects (swaths) at six long-term monitoring sites from 1980-2018. A second data set consists of total counts of adult California sheephead (Semicossyphus pulcher), an important sea urchin predator, on these sites from 1981-2018. The third data set gives an index of the relative substrate rugosity in the form of replicate distances along the bottom profile of each permanent swath. Finally, bottom temperatures recorded from 2015-2019 show the relatively homogenous water mass that encompasses all the sites.