Ultraviolet radiation and natural sunscreens in Antarctic krill ...

• Main Author: Newman, SJ
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: Antarctic; Southern Ocean; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: https://dx.doi.org/10.25959/23230199; https://figshare.utas.edu.au/articles/thesis/Ultraviolet_radiation_and_natural_sunscreens_in_Antarctic_krill/23230199

This thesis examines the adaptations of Antarctic krill (Euphausia superba Dana) to ultraviolet radiation in terms of susceptibility, behavioural avoidance and the presence/utility of UV-absorbing mycosporine-like amino acids (MAAs). In order to test the susceptibility of krill to UVB (280-320 nm) radiation, groups of animals in laboratory tanks were irradiated with various light treatments in order to determine lethal dose and effect on generalised activity. It was found that krill were killed within 3 days (8 hours of irradiation per day) by levels of UVB radiation equivalent to that at 5-15 m depth in the Southern Ocean in Spring. UV A (320-400 nm) was found to have no more effect on mortality and activity than visible light (PAR, 400-700 nm) only. This showed that krill are remarkably susceptible to low levels of UVB radiation, and are therefore at risk given their photic zone habitat. The behaviour of krill in response to gradients of visible light (photosynthetically active radiation, PAR), ...