How many fish is there in the ocean?

There is no definitive answer to how many fish exist in the ocean because the ocean is vast and many fish species are difficult to count accurately. However, there are some estimates that can provide a general idea of the magnitude of fish populations.

One study, published in the journal Nature in 2010, estimated that there are approximately 20 trillion fish in the world's oceans. This estimate includes all bony fish, which make up a significant portion of marine fish species. According to this study, the most abundant fish species are anchovies, followed by lanternfish, bristlemouths, and deep-sea smelts.

However, it is important to note that this estimate is based on limited sampling and assumptions, and actual fish populations may vary. Fish populations can fluctuate due to various factors such as fishing pressure, environmental changes, and natural population dynamics.