Fisheries managers and researchers can now predict how early spawning fish respond to water warming due to climate change, both in the oceans and in freshwater.

A new simple model developed by researchers from the University of British Columbia and the Chinese Academy of Sciences and applied to temperate fish that spawn in spring, allows you to fairly accurately predict changes in maturation and spawning in terms of changes in average annual temperature.

Built based on seasonal descriptions temperature The changes represented by the two sinusoidal curves, the model is based on the notion that a certain temperature threshold when reached is that triggers a hormonal cascade that “tells” the fish that it is time to breed.

But when the water temperature rises, this process goes out of balance, because fish need more oxygen to survive. The problem is that their gills, which are two-dimensional surfaces, cannot keep up with the oxygen demand of their three-dimensional growing bodies and the new oxygen demand caused by temperature. This imbalance thus strains the fish and causes them to mature and spawn earlier.

If the average annual temperature in a given area and period increases, this leads to the fact that spring temperatures “come” earlier. Our new model, which assumes seasonal temperature fluctuations observed in nature, requires as input only the difference in average temperature between two periods and temperatures between summer and winter.Only with these two figures the model predicts how many days spawning fish is accelerating, ”said Dr. Daniel Polly, principal investigator of the UBC Institute of Oceans and Fisheries’ Sea Around Us initiative and lead author of the study, published in Ecological fish biology.

“It’s simple model Hopefully, it will replace the complex hypotheses that are often presented to explain the temporal shift of spawning in terms of adapting to such shifts in the emergence of prey species that only replace one mystery to another but do not explain much, if anything, ”said Dr. Cui Liang, research co-author and researcher at the CAS Institute of Oceanology.

Fisheries managers and researchers can now predict how early spawning fish respond to water warming due to climate change, both in the oceans and in freshwater.

A new simple model developed by researchers from the University of British Columbia and the Chinese Academy of Sciences and applied to temperate fish that spawn in spring, allows you to fairly accurately predict changes in maturation and spawning in terms of changes in average annual temperature.

Built based on seasonal descriptions temperature The changes represented by the two sinusoidal curves, the model is based on the notion that a certain temperature threshold when reached is that triggers a hormonal cascade that “tells” the fish that it is time to breed.

But when the water temperature rises, this process goes out of balance, because fish need more oxygen to survive. The problem is that their gills, which are two-dimensional surfaces, cannot keep up with the oxygen demand of their three-dimensional growing bodies and the new oxygen demand caused by temperature. This imbalance thus strains the fish and causes them to mature and spawn earlier.

If the average annual temperature in a given area and period increases, this leads to the fact that spring temperatures “come” earlier. Our new model, which assumes seasonal temperature fluctuations observed in nature, requires as input only the difference in average temperature between two periods and temperatures between summer and winter.Only with these two figures the model predicts how many days spawning fish is accelerating, ”said Dr. Daniel Polly, principal investigator of the UBC Institute of Oceans and Fisheries’ Sea Around Us initiative and lead author of the study, published in Ecological fish biology.

“It’s simple model Hopefully, it will replace the complex hypotheses that are often presented to explain the temporal shift of spawning in terms of adapting to such shifts in the emergence of prey species that only replace one mystery to another but do not explain much, if anything, ”said Dr. Cui Liang, research co-author and researcher at the CAS Institute of Oceanology.