Variation in sunscreen compounds (mycosporine‐like amino acids) for marine species along a gradient of ultraviolet radiation transmission within doubtful sound, New Zealand

Abstract

We examined the response of four species of New Zealand marine algae (Ecklonia radiata, Apophlaea lyallii, Rhodymenia spp., Ulva lactuca) and a sea urchin (Evechinus chloroticus) to spatial variation in ultraviolet radiation (UV-R) by examining the concentration of UV-R absorbing compounds known as mycosporine-like amino acids (MAAs). The purpose was to understand how, and the degree to which, local marine species could potentially respond to any future increases in incident UV-R in the New Zealand marine environment. The research was undertaken in Doubtful Sound, where we observed a gradient of water column UV-R transmission along the 40 km length of the fiord. We examined spatial differences in MAAs along the UV-B gradient in the macrophytes and temporal changes in MAAs in sea urchin gonads. Among the algae, thallus MAA concentrations (nmol mg -1 protein) ranged from 12.5 to 87.8 in E. radiata, from 433.1 to 1446.4 in A. lyallii, 12.7 Rhodymenia spp., but were not detected in U. lactuca. For E. chloroticus, gonadal MAA concentrations ranged from 83.9 to 224.3 nmol mg -1 protein spatially, and over the year from 1.85 to 14.12 nmol mg -1 dry weight (DW) depending on site and gametogenic cycle. Laboratory manipulations indicated that concentrations of MAAs in E. chloroticus gonads and eggs are influenced by diet. MAA concentration could be correlated with UV-B intensities in two of the algal species. E. chloroticus MAA concentrations could also be correlated with UV-B transmission, which we concluded was a reflection of the greater ingestion and accumulation of MAArich macrophytes at those sites where higher ambient UV-R induced greater MAA concentrations to occur in the algae. Given this, we suggest that one response of marine species to increases in UV-B would be an increase in the synthesis and/or accumulation of MAAs for photoautotrophs and a dietary accumulation of those MAAs in E. chloroticus, an important herbivore in this system.

The influence of environmental features in the content of mycosporine‐like amino acids in red marine algae along the Brazilian coast

“…The environmental features that enhanced MAA concentrations in the oceanic islands region were characterized by possessing clear and oligotrophic water, allowing greater penetration of solar radiation reinforcing the results of Carreto et al (1990), Karsten et al (1998a) and Lamare et al (2004) which stated that UVR directly influences the MAA concentrations. The MAA content that we found in species from Atol das Rocas can indicate a molecular and ecophysiological effort against the strong influence that UVR has on tropical reef environments with oligotrophic characteristics and attenuation of UVR, as observed by (Karsten et al 1998a, Banaszak and Lesser 2009, Moreau et al 2016).…”

“…() and Lamare et al. () which stated that UVR directly influences the MAA concentrations. The MAA content that we found in species from Atol das Rocas can indicate a molecular and ecophysiological effort against the strong influence that UVR has on tropical reef environments with oligotrophic characteristics and attenuation of UVR, as observed by (Karsten et al.…”

“…The salinity does not appear to be a factor that directly impacts the concentration of MAAs, but acting in a secondary way by the influence on other factors, for example, reducing the penetration of ultraviolet radiation in the water column (Lamare et al. ).…”

Cellular Changes Associated with the Acclimation of the Intertidal Sea AnemoneActinia tenebrosato Ultraviolet Radiation

“…As most invertebrates lack the ability to synthesize MAAs, those that do not establish symbiotic associations with microalgae acquire MAAs entirely from a dietary source, e.g. Aplysia dactylomela , Strongylocentrotus droebachiensis , Evechinus chloroticus , E. superba and Leptodiaptomus minutus . Thus, the level of MAAs in the food consumed determines the level of accumulation of MAAs within these invertebrates.…”

UV-induced DNA damage in coral reef fish: damage levels and protection mechanisms

“…The efficacy of these natural sunscreens in preventing UV-induced DNA damage has not directly been shown (Bandaranayake 1998 habitat (Zamzow 2007, Zamzow et al 2013 and is strongly reduced under UV-lacking conditions (Zamzow 2004). Similar relationships from invertebrates (Banaszak et al 1998, Lamare et al 2004) also strongly suggest a protective function of MAAs against the negative effects of UVR. Fish that have UV vision/communication would need to reduce their MAA content in order to send and receive their signals, which could explain differences in mucus absorbance between a pomacentrid and a labrid species (Zamzow & Siebeck 2006).…”