We present a GIS method for mapping and characterizing nearshore reef habitats. Utilizing this technique, we were able to successfully map all nearshore (<30 m depth) rocky reefs in the Southern California Bight and then quickly assess and characterize these data layers with expert opinion. The southern California coastline is 1198 km in length, with the eight Channel Islands and mainland comprising 503 km and 695 km of coastline, respectively. This is approximately the same amount of coastline as the rest of California. Within this region, we identified and characterized 122 natural reefs comprising 49,055 hectares, which is 26.6% of the 184,439 ha of nearshore habitat in the bight, the remainder comprised of soft bottom. Reefs varied appreciably in size ranging from 6 – 2498 ha. We sampled a subset of these reefs using a generalized random tessellation stratified design and quantified their physical characteristics as measured by scuba surveys. The reefs also varied with respect to habitat type and five distinct sub-habitat types varying from sheer oceanic pinnacle reefs to low-lying cobble were observed. The distribution of reef types varied between the mainland and islands. Island reefs were, in general, higher relief and had a greater percentage of rocky substrate. Mainland reefs generally had lower relief and a higher percentage of sand and cobble substrates.

A 14-month study was conducted of the marine wood borers present on suspended wooden blocks replaced monthly at nine stations in Los Angeles Harbor in 2013-2014, and compared to the results of a marine borer study conducted in 1950-1951. Many environmental changes have occurred in the harbor over the past 63 years. The harbor land mass of the outer harbor has been expanded towards the breakwater, channels deepened, and the water quality improved as a result of pollution abatement. Existing pilings removed, replaced or covered with two layers of polyethylene. The isopod Limnoria tripunctata and the bivalve Lyrodus pedicellatus were the principal species. The station located in the Consolidated Slip area of the inner harbor was the site of 87 and 58 percent of the Limnoria and Lyrodus, respectively, counted during the study. Neither of these species present at this station in 1950-1951. The dissolved oxygen concentration at this station improved from a mean of 0.1 ppm in 1950-1951 to a mean of 6.7 in 2013-2014 as a result of improved environmental conditions. Larval settlement at Cerritos Channel numbered in the thousands in 1950-1951 but only 22 were counted during the 2013-2014 survey. This difference was attributed to the effect of piling covering or removal. It is recommended that existing creosoted pilings be covered or removed in the inner harbor area since this was the region of greatest occurrence of wood borers in 2013-2014.

Benthic macroinvertebrate (BMI) sampling was conducted at two sites in Topanga Creek from 2003-2014. During this period, Southern California experienced extreme drought conditions (US Drought Monitor 2014). Examining trends in species composition over this period allows for a relatively long-term analysis of potential effects of drought on BMI communities. The Southern California Coastal Index of Biotic Integrity (SCC-IBI; Ode 2007) was applied to BMI samples from Topanga Creek to measure the effects of drought on quantitative biotic integrity. The following trends regarding the BMI community of Topanga Creek emerged during the course of this study: 1) Wet year rainfall in Topanga Creek Watershed positively correlated to relative and per sq. ft. springtime abundance of Baetis sp., relative abundance of Simulium sp. up to 78.7 cm (31") rain, and negatively correlated to relative abundance of Chironomidae n.d., 2) percent algae cover in April and May positvely correlated to abundance per sq. ft. Baetis sp. and Simulium sp., and 3) multiple regression analysis revealed a negative relationship between Chironomid n.d. and Baetis sp. abundance. BMI are an important food source for endangered steelhead trout and other native aquatic and terrestrial insectivorous species of special concern; significant changes to the BMI community could have trophic reprecussions for these and other wildlife. Long-term monitoring is important for tracking the influence of changes in climatic conditions on BMI community.