Environmental Constraints on Spawning Depth of Yellow Perch: The Roles of Low Temperature and High Solar Ultraviolet Radiation

Abstract

The roles of temperature and ultraviolet radiation (UVR) in determining the spawning success of yellow perch Perca flavescens were investigated in two Pennsylvania lakes with different dissolved organic carbon (DOC) concentrations. In situ incubation experiments were used to manipulate temperature and UVR and to examine hatching time and hatching success. Extensive scuba surveys were used to document actual spawning depths. Differences in the temperature and UVR profiles of the two lakes led to contrasting responses of incubated yellow perch eggs. Higher temperatures in the surface waters of the higher‐DOC lake led to hatching times that were 10–26 d shorter than those in the surface waters of the low‐DOC lake or in the deeper waters of the higher‐DOC lake. The high levels of UVR in the surface waters of the low‐DOC lake killed 100% of the eggs before hatching. Ultraviolet radiation had little effect on survival in the higher‐DOC lake or in deeper waters of the low‐DOC lake. Scuba surveys revealed that spawning in the low‐DOC lake occurred at greater depths than previously recognized. Ninety‐two percent of the eggs spawned in the low‐DOC lake were located at depths greater than 3 m, while 76% of eggs in the higher‐DOC lake were spawned in water less than 1 m deep. Temperature and UVR are both important in determining among‐lake differences in spawning depths of yellow perch. Yellow perch are able to spawn at shallow depths in higher‐DOC lakes, where warmer temperatures accelerate developmental rates and DOC blocks potentially damaging UVR. In low‐DOC lakes, yellow perch must spawn at greater depths to avoid UVR damage. Spawning at greater depths may be costly due to the substantially slower developmental rates at lower temperatures. Our data suggest that the conflicting selective pressures of UVR and temperature create an optimal spawning‐depth range for yellow perch that differs among lakes as a function of DOC concentration.

Location and timing of the deposition of egg strands by perch (Perca fluviatilisL.): the roles of lake hydrology, spawning substrate and female size

“…The present study focused on the location and timing of the deposition of egg strands by perch in the newly created Chabařovice Lake. In this lake, Čech et al (2009, 2010) have previously reported that 92% (year 2007) and 88% (2008) of egg strands were deposited at depths greater than 3 m which closely resembles the situation in the low-DOC Lake Giles, Pennsylvania, described by Huff et al (2004;92% of egg strands were deposited at depths greater than 3 m). In Chabařovice Lake, the concentration of DOC has never been analyzed.…”

“…The mean concentration of DOC in the lake was 6.2 mg · L −1 (min.-max., 5.7-7.6 mg · L −1 ) indicating that according to the classification of Huff et al (2004) Chabařovice Lake belongs to the category of higher-DOC lakes, i.e. to the category where DOC (penetrating UVR in fact) is not responsible for deep deposition of egg strands of perch.…”

“…Treasurer, 1983;Rask et al, 1990;Sandström et al, 1997;Huff et al, 2004;Gillet and Dubois, 2007;Čech et al, 2009). Frequently lake hydrology and, especially, prevailing wind and from that resulting waves, also contributed significantly to the place and depth of egg strand depositions as well as to the length of the spawning period (Jones, 1982;Newsome and Aalto, 1987;Probst et al, 2009).…”

“…Completely opposite results have, however, been published from Klíčava Reservoir, Czech Republic (Holčík, 1969; female size only) and from an inundated quarry pit, La Gombe, Belgium (Dalimier et al, 1982). More recently, Williamson et al (1997) and Huff et al (2004) have shown that the concentration of dissolved organic carbon (DOC) plays a crucial role in the depth distribution of egg strands. In low-DOC lakes (DOC~1.1 mg · L −1 ) where damaging ultraviolet radiation (UVR) penetrates to deeper layers of the water column, perch, in an effort to protect their eggs, are forced to spawn in much greater depths compared to higher-DOC lakes (DOC 4.7 mg · L −1 ; Huff et al, 2004).…”

“…More recently, Williamson et al (1997) and Huff et al (2004) have shown that the concentration of dissolved organic carbon (DOC) plays a crucial role in the depth distribution of egg strands. In low-DOC lakes (DOC~1.1 mg · L −1 ) where damaging ultraviolet radiation (UVR) penetrates to deeper layers of the water column, perch, in an effort to protect their eggs, are forced to spawn in much greater depths compared to higher-DOC lakes (DOC 4.7 mg · L −1 ; Huff et al, 2004). The present study focused on the location and timing of the deposition of egg strands by perch in the newly created Chabařovice Lake.…”