Environmental fluctuations can generate asynchronous species’ fluctuations and community stability, due to compensatory dynamics of species with different environmental tolerances. We tested this hypothesis in intertidal hard-bottom communities of north-central Chile, where a persistent upwelling centre maintains a mosaic in sea surface temperatures (SST) over 10s of kilometres along the shore. Coastal upwelling implies colder and temporally more stable SST relative to downstream sites. Uni- and multivariate analyses of multiyear timeseries of SST and species abundances showed more asynchronous fluctuations and higher stability in sites characterised by warmer and more variable SST. Nevertheless, these effects were weakened after including data obtained in sites affected by less persistent upwelling centres. Further, dominant species were more stable in sites exposed to high SST variability. The strength of other processes that can influence community stability, chiefly statistical averaging and overyielding, did not vary significantly between SST regimes. Our results provide observational evidence supporting the idea that exogenously driven compensatory dynamics and the stabilising effects of dominant species can determine the stability of ecosystems facing environmental fluctuations.

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Biofouling control on human-made structures and seagoing technologies that minimize environmental impacts is a major focus of research in marine industries. However, the most widely used antifouling (AF) method is still copper-based coatings. Some “eco-friendly” approaches are commercially available but have been scarcely tested in natural conditions, especially high-energy environments. We conducted a replicated long-term field experiment in a highly wave-exposed, high productivity coastal environment to test three untreated materials used in maritime industries, two traditional copper-based AF coatings, and two materials offered as “eco-friendly” AF in the market (i.e., a slow-copper release and a self-adhesive, fiber-covered, skin-like coating). We showed that biofouling cover and biomass increased at similar rates over time among all untreated materials, including the skin-like AF. The two traditional copper-based AF coatings and the slow-release AF paint both showed similarly low biofouling biomass and richness, demonstrating their efficacy after 12 months in the field. Although the “eco-friendly” slow-release technologies are not completely innocuous to the environment, we suggest this approach over the more environmentally aggressive traditional copper paints, which are the most widely used in aquaculture and shipping industries today. However, further research is needed to test whether their environmental impact is significantly lower in the long-term than traditional AF paints, and therefore the search for non-toxic coating must continue. The fortuitous settlement and growth of sea urchins in our experiments also suggest that a combination of “eco-friendly” AF and biological control would be possible and should be further investigated. The skin-like coatings must be tested under different environmental conditions, and they are not recommended in wave-exposed coastal habitats.

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