This paper examines the potential of polysulphone film (PSF) as a dosimeter for unweighted solar ultraviolet-B radiation (UVB; 280 to 320 nm) in different seawater conditions in tropical latitudes. PSF's accuracy is determined by water type and depth range. The film may be used over a depth range of 7 m with measurement errors of less than 5 % in oceanic type waters, such as are found around co...

We examined the effects of UV radiation (UVR) on metabolic rates of the freshwater cladoceran Daphnia catawba. We exposed D. catawba to UVB for 12 h in a lamp phototron at levels of 2.08 and 4.16 kJ m(-2) both with and without concomitant exposure to UVA and visible photorepair radiation (PRR). We also included a group that received PRR only and a dark control group. Respiration rates were meas...

Radiochromic film is tested for its broad-band response to ultraviolet (UV) B (290-320 nm) and A (320 nm400 nm), visible and infrared radiation produced by a solar simulator and examined for dosimetry in ultraviolet radiation. Results show that MD-55-2 radiochromic film in solar and fluorescent light sources responds almost exclusively to broad-band UVA radiation with negligible colouration fro...

Mixing of seawater subjects phytoplankton to fluctuations in photosynthetically active radiation (400-700 nm) and ultraviolet radiation (UVR; 280-400 nm). These irradiance fluctuations are now superimposed upon ocean acidification and thinning of the upper mixing layer through stratification, which alters mixing regimes. Therefore, we examined the photosynthetic carbon fixation and photochemica...

Although ultraviolet radiation is potentially harmful, it is an important component of terrestrial radiation to which plants have been exposed since invading land. Since then, plants have evolved mechanisms to avoid and repair UV radiation damage. Therefore, it is not surprising that photomorphogenic responses to UV-B and UV-C are often assumed to be adaptations to harmful radiation. Most of th...