Effects of Coral Diversity Decline May Lead to 40% Reduction in Reef Fish Diversity, Study Says

Millions of people across the globe look to the ocean to provide them food, nutrition, and livelihood. However, with the effects of climate, the future is not so bright for aquatic life. Predicting the effects of coral loss on various fish communities across the globe is a fundamental task of many researchers.

A study led by researchers from the University of Helsinki predicts that the effects of coral diversity decline will lead to at least a 40% reduction in reef fish diversity.

Why is Coral Reef Diversity Important?

(Photo : Tom Fisk from Pexels)

One of the most diverse ecosystems on Earth is coral reefs. They serve as a home for more than 25% of all marine life that occupies less than a percent of the planet's oceans, according to the Coral Reef Alliance. Sponges and corals of varying sizes and textures, the smallest fishes such as pygmy seahorses, and the biggest fish such as tiger sharks, anemones, nudibranchs, snails, and more thrive on the existence and diversity of coral reefs.

We know that corals face a devastating and uncertain future due to the many threats it faces today. Local threats like overfishing and pollution, global threats like ocean acidification, and climate change are painting a deem future for the diversity of coral reefs. Without reef-building corals such as elkhorn and staghorn, there will be no habitat for the numerous life forms that call reefs home.

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Studying the Effects of Coral Diversity Decline

As of late, researchers have been facing obstacles in conducting large-scale studies to project what fish will remain in the planet's oceans without corals. A recent study led by Giovanni Strona from the University of Helsinki found that global projection for fish diversity without corals is as low as small-scale experiments could ever suggest.

In a study published in the journal Proceedings of the Royal Society B, entitled "Global tropical reef fish richness could decline by around half if corals are lost" a team of international marine biologists began to map tropical fish and coral diversity in various oceans for every square degree of longitude and latitude.

The maps echoed that fish and coral diversity varied widely, with more species in the Indo-Pacific çoral triangle' compared to the western Atlantic and eastern Pacific.

After fitting the line between fish diversity and coral diversity, researchers conducted a simple experiment. Anticipating global coral extirpation vs coral association down to the point where no other coral species would be left. This suggested that roughly 40% of the world's tropical reef fish would likely disappear should corals get wiped off the face of the planet.

The number is much more intense in other areas, where the Central Pacific is expected to lose roughly 60% of its reef fish, with the Western Atlantic losing only 10%. Strona explains that the team first created statistical models that would disentangle the effects of biogeography, environment, and history on fish and coral reef diversity to accurately predict local-scale fish diversity in response to numerous environmental variables including water temperature, salinity, pH, and coral diversity, ScienceDaily reports.