Through fisheries and aquaculture, the varied group of vertebrates known as fish sustains billions of people worldwide. The “shrinking” tendency is caused by the fact that fish are getting smaller as their habitats warm up.
It is anticipated that this trend would make the marine ecological effects of global warming worse. Although widely established, the relationship between warmer water and smaller size is not fully understood.
Global Warming Affects the Size of Fish
The “temperature-size rule” is based on experiments showing that fish grow lower in size when housed in warmer environments. Each fish will have fewer progeny as a result of this declining population, which might have significant ecological and economic repercussions.
According to the most widely accepted ideas, the reason for this shrinking is a discrepancy between the amount of oxygen a fish needs to maintain its body’s metabolism and the amount it can obtain (through its gills).
- Fisheries sustain billions; shrinking due to habitat warming.
- Temperature-size rule impacts fish growth, reducing progeny and impacting ecosystems.
- Extinct species threatened by rising temperatures; climate change impacts fisheries and aquaculture.
Long-term studies have revealed, however, that as fish get bigger, the oxygen supply can keep up with the demand. In warmer environments, fish typically grow more quickly and mature early and in smaller sizes. This might be the result of energy being directed toward reproduction rather than further growth.
Fish can’t continue to get smaller forever. Each species must grow to a certain minimum size to maintain a healthy population. When a species reaches its unique thermal threshold in a given area, it will no longer be able to reproduce and will go extinct in that area.
The species will go extinct if the temperature in its entire home range rises too much. As we move forward into a future with a warmer, harsher climate, these considerations of smaller fish and shifting thermal habitats will be crucial for the viability of fisheries and aquaculture enterprises.