UV damage and photoreactivation potentials of larval shrimp, Pandalus platyceros, and adult euphausiids, Thysanoessa raschii

Abstract

Previously reported thresholds for UV-B dose and dose-rate were determined under artificial light regimes using more than an order of magnitude less visible light than found naturally. Near-UV and/or visible light is needed for photoreactivation, and the accuracy of earlier findings may have been influenced by less than maximum photorepair in the laboratory. Experiments with shrimp larvae and adult euphausiids, comparing survival at various UV-B doses and dose-rates combined with different levels of near-UV and visible irradiance, suggest that photorepair occurs in these organisms. Further, this apparent photorepair reaches maximum levels at relatively low visible light intensities.Previously reported tolerance limits for shrimp larvae and adult euphausiids were confirmed (in particular, the relationship between dose/dose-rate safe and lethal limits in shrimp). Also, the earlier experimental design did not appear to have affected these limits since additional near-UV and visible light did not substantially alter the results.In experiments using a 44-1 plastic cylinder (140-cm water depth), adult euphausiids successfully avoided moderate UV-B combined with visible light, but were attracted to and ultimately killed by higher levels of UV-B combined with low visible light. The apparent inability of euphausiids to directly detect harmful levels of UV-B irradiance would become an important factor in a new solar spectral distribution caused by ozone depletion.

Dose and dose-rate dependency in the mortality response of Calanus finmarchicus embryos exposed to ultraviolet radiation

“…In marine crustaceans, reciprocity failed to hold for larvae of the shrimp Pandalus platyceros (Damkaer et al 1981) and for adults of the euphausid Thysanoessa raschii (Damkaer & Dey 1983). Neither does reciprocity hold for freshwater species such as the cladocerans Daphnia spp.…”

Zooplankton vertical migration and plasticity of pigmentation arising from simultaneous UV and predation threats

“…Because of this lag, organisms may not be able to respond to large fluctuations in the environmentthey do not have the proper adaptations. An example of such a situation can be the inability to detect increases in harmful ultraviolet (UV) radiation due to ozone thinning (specifically UV-B) (Damkaer and Dey 1983), which results in increased mortality.…”

Zooplankton survival and reproduction responses to damaging UV radiation: A test of reciprocity and photoenzymatic repair

“…A growing number of authors have explored the effects of UV-B on aquatic organisms, including rotifers (Cabrera et al 1997), copepods (Tartarotti et al 1999), Daphnia (Zagarese et al 1994), shrimp and euphausids (Damkaer and Dey 1983), fish (Gutiérrez-Rodríguez and Williamson 1999), as well as effects on planktonic communities Mostajir et al 1999). In all cases, UVR was found to harm the organisms in question by decreasing their survival during at least one life stage.…”

“…tion of reciprocity, either explicit or implicit, is common to many studies of UVR effects. Often, reciprocity is assumed to hold (Damkaer et al 1981;Smith and Baker 1982) or its importance is acknowledged (Béland et al 1999;Kouwenberg et al 1999) though it is not directly tested. Trocine et al (1981) found that at a given UV-B dose, low dose rates over a long period of time produced the same degree of photosynthetic inhibition as higher dose rates over a shorter period of time in two of three species of seagrasses.…”