New data models are showing how climate change is inducing early spawning in fish. This research is showing that as water temperature increases in the spring, fish require more oxygen to survive. This earlier seasonal water warming event stresses fish and makes them ready to spawn earlier. The previous theory to explain shifting of spawning was linked to emergence of prey species in the spring, however that is now being discounted due to new research. If you are interested in reading more about this, you can check out the related science articles links below:

https://phys.org/news/2022-01-link-respiratory-stress-fish-reproduction.html