| Autor: |
AARSETH, KNUT A., SCHRAM, THOMAS A. |
| Předmět: |
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| Zdroj: |
Journal of Plankton Research; Jul2002, Vol. 24 Issue 7, p661-679, 19p, 4 Charts, 9 Graphs |
| Abstrakt: |
Copepods were exposed to UVB with a spectral irradiance maximum at 313 nm and additional visible light. In the holopelagic Calanus finmarchicus, with a carotenoid concentration of 0.85 μg mg−1, the LD50 dose was 29 kJ m−2 whereas in the parasitic copepod Lepeophtheirus salmonis the LD50 was 84 kJ m−2. The ability to photorepair was demonstrated for both species. The survival data were Weibull distributed, and this result is discussed relative to a mechanistic ‘Weibull model’. Attenuation of UVB (306 nm) was measured in the inner Oslo fjord (Kd = 3.9 m−1). The adaptive significance of behavioural avoidance is assessed in model simulations; the results of the survival experiments are used in connection with the Morowitz formula. Two cases were compared; when Calanus was assumed incapable of active external filtering the specimens would be safe if the depth of the mixed layer was deeper than 7 m in the inner Oslo fjord, however, with the ability of behavioural avoidance, Calanus would be protected if they avoided the upper 1 m. The adaptive value associated with behavioural avoidance of toxic radiation, and the implications relative to vertical migration are discussed. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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