Describe why biodiversity increased with the introduction of sea otters in California over the last fifty years

Due to increment in food chains.

Explanation:

Biodiversity is actually the measure of changes in the ecosystem, genetic levels and various species levels. The sea otters introduced in California over last fifty years, increased the diversity in the ecosystem as well as in species too, thus changing the biodiversity. This was the impact of increase in food web in that particular area, the number of consumers, producers and prey increased thus increasing the biodiversity.