A group of researchers determined that in the past 30 years, Alaskan salmon's spawning time in the Gulf of Alaska changed for up to three weeks, and attributed this change to climate change and the impact of fishing.
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Scientists explain that if the spawning group comes too early, there may not be enough food; if it comes too late, the growth time of the juvenile fish will be compressed, lacking a competitive advantage. In addition, since most deaths occur in the first few weeks after the birth of the carp, changes in spawning time will affect the survival rate of the juvenile, which will directly affect how many fish are available for fishing after two or three years of fishing. The leader of the study, NOAA fish biologist Lauren Rogers, explained that in order to effectively monitor and manage salmon populations, managers need to understand what caused the change in spawning time.
As the global ocean continues to warm, it is necessary to understand how changes in climatic conditions interact with other processes, such as fishing, which in turn affects spawning time. To this end, Rogers' team investigated the spawning time and age structure of the squid in the Gulf of Alaska during warm and cool periods. This study combines a surprising 32-year time series of juvenile fish size, age, and abundance information that is validated by maternal sexual maturity data and with sea surveys, laboratory experiments, and age reading data. Combine. Using this data, her team was able to calculate the impact of climate and age structure on spawning time and duration, and predict spawning time in different conditions of warming water and fishing mortality.