UV effects that come and go: a global comparison of marine benthic community level impacts

Abstract

Ambient UV radiation has substantially increased during the last decades, but its impact on marine benthic communities is hardly known. The aim of this study was to globally compare and quantify how shallow hard-bottom communities are affected by UV during early succession. Identical field experiments in 10 different coastal regions of both hemispheres produced a consistent but unexpected pattern: (i) UV radiation affected species diversity and community biomass in a very similar manner, (ii) diversity and biomass were reduced to a larger extent by UVA than UVB radiation, (iii) ambient UV levels did not affect the composition of the communities, and (iv) any UV effects disappeared during species succession after 2-3 months. Thus, current levels of UV radiation seem to have small, predictable, and transient effects on shallow marine hardbottom communities.

Susceptibility of zoospores to UV radiation determines upper depth distribution limit of Arctic kelps: evidence through field experiments

“…The adult macrothalli of L. digitata are clearly sun adapted and can cope very well both with high PAR and with UVBR (Hanelt et al 1997;. Additional biotic factors, such as competition or grazing, as exemplified by Wahl et al (2004), require further investigation.…”

Ultraviolet radiation shapes seaweed communities

“…Only a few studies assessed UV-effects during species succession of shallow-water seaweed-dominated communities (Santas et al 1998;Molis et al 2003;Molis and Wahl 2004;Wahl et al 2004;Dobretsov et al 2005). Surprisingly in all but one study (Dobretsov et al 2005), UV-effects were only apparent during the early phase of succession.…”

“…To our knowledge, only the study by Wahl et al (2004) investigated UV-effects on shallow-water macro-epibenthic assemblages at different bio-geographical regions. Their study revealed a consistent pattern of UV-effects at both hemispheres.…”

“…Thus, macroalgal propagules may show species-specific differential UV-sensitivities, which favour initial colonisation of empty space by UV-resistant species. Wahl et al (2004) suggested that these early colonizers facilitate the recruitment of later successional seaweed and invertebrate species at the majority of their study sites by amelioration of UV-regimes due to protective shading. Similarly Vinebrooke and Leavitt (1999) concluded that diatom mats can precondition the substratum for macroalgal spores by provision of UV-free micro-climates.…”

Morpho-functional patterns and zonation of South Chilean seaweeds: the importance of photosynthetic and bio-optical traits

“…It must be emphasized that the effect of UV varies between species (Wahl et al 2004, Bancroft et al 2007, and additionally, seaweeds are able to counteract the negative UV effects through different adaptive responses (reviewed by Bischof et al 2006b). Based on pure optics only, one may argue that thicker seaweeds by virtue of their characteristics (e.g.…”