* Increased metabolism: Warmer water temperatures increase the metabolic rate of fish, causing them to burn energy more quickly. This can lead to weight loss, reduced growth, and increased susceptibility to disease.

* Altered enzyme activity: Enzymes are proteins that catalyze chemical reactions in the body. The activity of enzymes is affected by temperature, and warmer water temperatures can cause enzymes to function less efficiently. This can disrupt a variety of bodily processes, including digestion, respiration, and reproduction.

* Increased production of stress hormones: Warmer water temperatures can also cause fish to produce more stress hormones, such as cortisol. These hormones can have a negative impact on growth, reproduction, and immune function.

Growth effects

* Reduced growth rate: Warmer water temperatures can slow the growth rate of fish. This is because warmer water temperatures increase the metabolic rate of fish, causing them to burn energy more quickly. This leaves less energy available for growth.

* Reduced body size: Fish that live in warmer water temperatures tend to be smaller than fish that live in cooler water temperatures. This is because warmer water temperatures slow the growth rate of fish, and fish that live in warmer water temperatures have a shorter growing season.

* Altered body shape: Warmer water temperatures can also alter the body shape of fish. For example, fish that live in warmer water temperatures often have a deeper body and a shorter snout than fish that live in cooler water temperatures.

Conclusion

Warmer water temperatures from climate change can have a significant impact on the biochemistry and growth of fish. These effects can lead to reduced growth rates, smaller body sizes, altered body shapes, and increased susceptibility to disease. These changes can have a negative impact on the health and survival of fish populations, and can also affect the productivity of fisheries.