UV radiation effects on the embryos of anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) off central Chile

Abstract

It has been proposed that current levels of ultraviolet B (UVB) radiation could cause lethal or sublethal effects on fish embryos located in the upper layers of the water column. Observed levels of UVB off central Chile (36°S, 73°W) indicate that planktonic fish embryos could be exposed to harmful UVB radiation. From July 2011 to January 2012 embryos from anchoveta (Engraulis ringens) and common sardine (Strangomera bentincki) were used to test experimentally whether the UVB levels in central Chile produce lethal or sublethal effects in epipelagic fish embryos. Simultaneously, whether the embryos might be exposed to harmful UVB levels in the field was investigated. Our experimental results show that UVB may cause a decrease in hatching success, changes in buoyancy and embryonic malformations. These results, along with the observed vertical distribution of embryos and UVB radiation levels in the field during late spring suggest that lethal and sublethal effects may be occurring in the embryos of both species.

Effect of ultraviolet radiation (UVR) on the life stages of fish

“…The most evident effects of UVR (mainly UVB) exposure are the reduction of survival rates and the increase in the number and types of developmental malformations in both embryos and larvae, when exposed to an acute dose, or for a shortand long-term exposure period. Subsequently, these developmental abnormalities have been associated with high mortality after UVR exposure (e.g., Dong et al 2007;Lesser et al 2001;Mahmoud et al 2009;Vásquez et al 2016) (Tables 1 and 2, see summary in Fig. 1).…”

“…Both species showed a decrease in hatching success, changes in buoyancy and the development of several malformations. Embryo abnormalities included blisters on the yolk at the earliest stages, twisting of the notochord at different levels of intensity in the most advanced stages, and the presence of dead tissue in all stages of development (Vásquez et al 2016).…”

Transcriptional changes in the gilthead seabream (Sparus aurata) skin in response to ultraviolet B radiation exposure

“…Although the ultraviolet B (UVB, 280-315 nm) represents only a low percentage of the total UVR reaching the water surface, more harmful effects are generally attributed to this band (Häder et al, 2015;Neale et al, 2021). In fish, commonly reported impacts of UVB exposure include (1) increased mortality (Fukunishi et al, 2006;Sucréet al, 2012), (2) development of body abnormalities (Nuñez et al, 2012;Vaśquez et al, 2016), (3) growth reduction (Vitt et al, 2017;, (4) behavioral changes (Pulgar et al, 2015;Valiñas and Walter Helbling, 2016), (5) immune system suppression (Markkula et al, 2005;Jokinen et al, 2011), (6) metabolic and physiological changes (Alemanni et al, 2003;Sharma et al, 2010), and (7) DNA damage and increased oxidative stress (Carrasco-Malio et al, 2014;Braun et al, 2016;.…”