Imagine a coral reef ecosystem in all its complexity. This turquoise sea hosts impressive coral gardens, aggregations of colorful fishes, hidden invertebrates, sleek sharks and giant turtles. When we close our eyes and envision such a tropical scene, we rarely, if ever, consider the microbial communities of a coral reef.
Microbes are a fundamental aspect of all marine ecosystems. Microbial agents (bacterium, fungus, viruses and protists) are also associated with reef-building corals. The abundance and function of the microbial community on reefs may also play an important role in coral health.
Coral health worldwide has declined in the last 20 years. Reasons for compromised coral health are numerous, and many are linked to humans and the way we affect our marine ecosystems. Examples of human induced impacts on oceans include marine pollution, overfishing, global climate change and ocean acidification. When coral health is compromised, microbes can infect corals and cause disease. Infectious coral diseases have increased in frequency and distribution since the 1970’s. These diseases continue to increase exponentially and have resulted in a significant loss of coral cover.
The global decline in coral cover has caused great concern. Coral diseases play a significant role in this decline. Researchers from around the world are devoting time and expertise to the study of coral disease. I am aboard the Hi’ialakai collecting and processing water samples for one of these researchers.
Each day while diving I use 4 Niskin bottles to collect 2-liter reefwater samples. The shipboard processing of these samples takes about two hours. At the end of this Northwestern Hawaiian Islands research cruise, the processed water samples will be shipped to San Diego State University for further analysis. While the work is not glamorous, it is important. And the view isn’t too shabby either.