Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. The dam lacks fish ladders which prevents upstream spawning. Adult cod form spawning aggregations from late winter to spring. The fish releases the spores after spawning. Some sea turtles migrate long distances between feeding and spawning grounds. Forage fish often make great migrations between their spawning, feeding and nursery grounds. The Chiloquin Dam has been removed to help improve sucker spawning habitat. Optimum temperatures for nesting and spawning range between . They provide ideal spawning and nesting grounds. Feeding ends once they enter into freshwater, which can be several months before spawning. Prior to spawning, depending on the species, salmon undergo changes. Females guard their redds until death, which comes within days of spawning. Externally fertilized eggs develop during synchronized spawning. They can look like an entirely different fish outside of spawning season. Most Atlantic salmon also die after spawning, but not all.