Coral disease

Coral cover in reef ecosystems has decreased significantly for a diverse set of reasons, ranging from variable environmental conditions to mechanical breakdowns from storms.

[1] Coral diseases have widespread implications, impacting entire ecosystems and communities of organisms.

Researchers are working to understand these diseases, and how potential treatments could stop these pathogens from causing the widespread death of corals in a way that permanently impacts the community structure of reefs.

For example, cyanobacteria pathogens are able to affect the coral’s ability to do work, including blocking nitrogen fixing.

The band can move across the surface of the colony at the rate of a few millimeters a day, leaving behind bleached skeletal material.

[1] Coral diseases that are distributed throughout an area can have a big impact on other parts of reef communities.

Specifically, White Pox disease in the Florida Keys have impacted the prevalence of A. Palmata corals by reducing their numbers by 70%.

[6] This shows that coral diseases not only impact individuals, but also have a ripple effect to entire reef communities.

Studies have found that some diseases impact aquarium corals, but are not an issue in the wild, and vice versa.

These differences in diseases in the wild and aquariums is thought to be because of the varying conditions in the two environments, including water quality and captive coral breeding.

Because of this, rising ocean temperatures related to climate change could be making coral diseases more prevalent, although evidence is not conclusive because of other complex factors that connect to seasonality.

[3] Furthermore, the rise in sea temperature from climate change is expected to increase the frequency and severity of tropical storms.

These storms do mechanical damage to reefs, through increased wave action, and stirring up and re-deposition of sediment.

[3] Other stress factors related to climate change include an increase in pollution for pathogens to feed on with more rain and runoff, increased ultraviolet radiation, and a reduction in the aragonite saturation of surface seawater that is connected with ocean acidification.

[5][6] This bleaching, partially caused by diseases, is linked to a decrease in coral cover and loss of biodiversity in reefs.

[citation needed] Coral diseases are also shown to impact other parts of reef communities.

[citation needed] There has been a recent push in conservation to research pathogen load on corals.