How Does Coral Bleaching Affect Coral Reefs? Why Does It Happen?

Various coral reefs are in a state of devastation due to coral bleaching.

Coral tissues end up devoid of colors and transparent due to this phenomenon. This ultimately leaves their white exoskeleton exposed.

Coral Bleaching Explained

When temperatures of the ocean are higher, coral bleaching naturally occurs. However, mass events have become more prevalent due to ocean heat waves.

From 2009 to 2018, the world lost 14% of its coral reefs. This is due to the rapid increase in sea surface temperature.

Since around 25% of the world's marine species are supported by coral reefs in the ocean, biodiversity declines among these reefs could end up leading to key species elimination.

Thousands of species would end up having fewer habitats. Their survival would also end up getting threatened.

Moreover, as more frequent and severe storms happen due to worsening climate change, coastal communities may face greater risks of surges without coral reef protection.

ALSO READ: Massive Coral Bleaching Due to Climate Change Makes It Harder for Reef Fish To Identify Competitors, Study Finds

Why Coral Bleaching Happens

Coral bleaching naturally occurs due to rising temperatures in the ocean. This is especially the case during summer or in natural weather conditions like El Nino.

However, human influences and activities have been exacerbating mass bleaching events.

Due to human-induced climate change, global ocean temperatures have been persistently rising. In the past century, sea temperatures have seen an average rise of 0.13 degrees Celsius each decade.

As a result, warmer waters have increased the vulnerability of coral reefs outside of such usual seasons. The coral reefs' ability to recover has also been left impeded by this.

Coastal development and sun exposure changes could have also been contributing to things. In particular, rising plastic pollution has been plaguing marine ecosystems and oceans lately. Tiny plastic particles known as microplastics are also affecting the water quality, consequently restricting or suffocating the reefs' sunlight access.

Ocean acidification could also result from elevated atmospheric CO2 levels and warmer waters. Because of this phenomenon, the chemical balance of the ocean could be altered as it may serve as a carbon sink for storing and absorbing carbon dioxide.

At present, the acidity experienced by coral reefs is stronger compared to what they experienced in the past 400,000 years.

However, the occurrence of coral bleaching is not equal. This phenomenon is most common in areas that have more extreme and frequent heat waves. In areas that have less heat stress and more stable temperatures, fewer coral reefs get bleached.

Nevertheless, with these great impacts of coral bleaching on coral reefs, it is crucial to forego fossil fuel dependence in order to dampen global warming, which could consequently reduce temperature rise and ocean acidification. It is also important to change coastal development and fishing practices and tackle the matter of plastic pollution in the ocean.