In British Columbia, movements of larger, mature lingcod into spawning habitat during January and February has been associated with a decrease in lingcod densities as well as fewer small (<50 cm TL) lingcod [20].
The species decline has been associated with water pollution in the Yangtze and dam construction that has blocked access to or changed the flow regime near the sturgeon's remaining spawning areas.
A similar but much smaller aggregation of whale sharks reported from Gladden Spit, Belize, was related to mass spawning of snappers [15], [16], whereas in the north-central Gulf of Mexico, a smaller aggregation of R. typus was associated with a fish spawning event [4].
In fact, a difference of 2°C can be associated with differences in spawning dates of 2 weeks to over a month (Myers et al. 1998).
Furthermore, although it is difficult to completely disentangle the effects of geographic and environmental distance, a higher proportion of the identified outlier loci were associated with environmental parameters on spawning grounds than with geographic variables.
Receptors for gonadotropin have been shown to be associated with return migration timing for spawning in chum salmon (Oncorhynchus keta; Onuma et al. 2010), a trait that could be under selection in all migratory salmonids.
At age 2 years, low investment in reproduction likely accounted for the lack of a somatic cost of reproduction, whereas at age 4 the absence was associated with heightened growth post-spawning enabling mature fish to catch up to immature fish.
F1 hatchery fish tended to spawn lower in the river, and this spawning location was associated with lower reproductive success.
In the same scaffold as H b-β1 an outlier in a nonsynonymous SNP (ss1712304723) was identified, which is associated with salinity (at surface and spawning depth) and oxygen level (at spawning depth).
