UV and Effects on Hatching of yellow perch.
From Fisheries and Oceans Canada publication
The level of ultraviolet radiation (UVR) is considered important in hatching success of yellow perch (Williamson et al. 1997). In a Pennsylvania study, incubation success was dependent upon the degree of exposure to UVR at different depths with different dissolved organic carbon (DOC) concentrations (Huff et al. 2004). High levels of UVR in surface waters with low DOC killed 100% of the yellow perch eggs, while UVR had little impact on egg survival in the high DOC lake. Depth of spawning differed, as 92% of the eggs deposited in the low DOC lake were at depths greater than 3m while 76% of the egg masses in the higher DOC lake were spawned at less than 1m. The authors suggest that perch spawn at greater depths to avoid UVR, but deeper spawning may reduce developmental rates because of the lower temperature (Huff et al. 2004).
