Pfaff, MC, et al. 2019. A synthesis of three decades of socio-ecological change in False Bay, South Africa: setting the scene for multidisciplinary research and management. Elem Sci Anth, 7: 32.

1. Thermal performance traits are regularly used to make forecasts of the responses of ectotherms to anthropogenic environmental change, but such forecasts do not always differentiate between fundamental and realised thermal niches. 2. Here we determine the relative extents to which variation in the fundamental and realised thermal niches accounts for current variation in species abundance and occupancy and assess the effects of niche-choice on future-climate response estimations. 3. We investigated microclimate and macroclimate temperatures alongside abundance, occupancy, critical thermal limits and foraging activity of 52 ant species (accounting for >95% individuals collected) from a regional assemblage from across the Western Cape Province, South Africa, between 2003 and 2014. 4. Capability of a species to occupy sites experiencing the most extreme temperatures, coupled with breadth of realised niche, explained most deviance in occupancy (up to 75%), while foraging temperature range and body mass explained up to 50.5% of observed variation in mean species abundance. 5. When realised niches are used to forecast responses to climate change, large positive and negative effects among species are predicted under future conditions, in contrast to the forecasts of minimal impacts on all species that are indicated by fundamental niche predictions.

Aim The species-area relationship-based method of setting habitat-specific conservation targets assumes that detectability of species is perfect. However, this assumption is often violated. This paper aimed to combine species-area relationship (SAR)-based target setting with multispecies occupancy models to better represent communities with a large proportion of rare species, such as marine invertebrate macrofauna, include variable species detection and quantify uncertainty around conservation targets.Location South African West Coast continental shelf.Methods The macro-infaunal dataset used in these analyses consisted of 427 species from 42 sites and 220 samples. To examine the effect of variable species detection and include uncertainty around conservation targets, we compared asymptotic estimator-based targets with those based on multispecies site occupancy models (MSOMs) in a Bayesian framework, which allowed us to account for the observation process and quantify uncertainty more comprehensively.Results Targets based on MSOM were generally higher than those based on asymptotic estimators, with wider credible intervals. Between 10% and 15% (95% credible interval) of the area should be protected to represent 80% of the species, with the exception of one habitat with many common species that had a conservation target of 2%.Main conclusions Detection error-corrected targets based on MSOM are higher than uncorrected targets based on asymptotic estimators for habitats with lower detection and higher proportions of rare species. Our estimated conservation targets are close to the 10% target for marine habitats set by the Convention of Biological Diversity and in line with international studies but should be considered minimum targets as they do not take into account species persistence. Our results affirm the value of the modified SAR approach, which is applicable to any marine or terrestrial ecosystem. Unlike earlier methods, our modification naturally quantifies uncertainty in estimated conservation targets providing a measure of target robustness for decision-makers.

Rhodolith beds have not previously been recorded in South Africa. A multidisciplinary research effort used remote sampling tools to survey the historically unexplored continental shelf off the Eastern Cape coast of South Africa. A rhodolith bed, bearing both living and dead non-geniculate coralline red algae, was discovered in the 30–65 m depth range off the Kei River mouth in the newly proclaimed Amathole Offshore Marine Protected Area. Some of the rhodolith forming coralline algal specimens were identified as belonging to at least three genera based on their morphology and anatomy, namely, Lithophyllum, Lithothamnion and a non-descript genus. Rhodolith mean mass and diameter were 44.85 g ± 34.22 g and 41.28 mm ± 10.67 mm (N = 13), respectively. Remotely operated vehicle (ROV) imagery revealed a suite of epibenthic red macroalgae associated with the rhodolith bed. Taxonomy, vertical structure and distribution of rhodoliths in South Africa require further investigation.