<center>![bolbo.jpg](https://files.steempeak.com/file/steempeak/ribbitingscience/b2ZppJp0-bolbo.jpg)
<sub>Image: Douglas J. McCauley</sub></center>

Bumphead parrotfish are the largest parrotfish, measuring 4.6 feet, 1.4 meters long. Using their heads to ram and their beak to chomp, these fish eat several tons of food annually, with the primary portion of their diet consisting of coral polyps. The large amount of carbonate waste they produce as a result of their diet in turn results in the white sands beaches that surround their reefs. This produces concerns about the impact that the parrotfish may be having on the long term health of the reefs considering the amount they consume in a given year. At the same time, their activity results in new areas being cleared for the coral and bits of coral being fragmented into these new areas, allowing the coral to spread, a bit like the way a bee ends up pollinating flowers.

In an attempt to better understand the fishes' dietary habits, the scientists decided to sample the live coral and coral rock of their surrounding habitat, as well as the fishes' fecal matter itself, in order to test the caloric values of each. The results were interesting as they showed that despite rock often being thought of as dead remnants of reefs, it possessed three times the calories of live coral due to other organisms moving into the remaining structures. Parrotfish waste was shown to not chemically alter their surrounding environment in any appreciable manner.

Read more: [University of California, Santa Barbara](https://www.news.ucsb.edu/2019/019421/reef-engineers)