Interview with a Scientist: Saving the Bumphead Parrotfish
More with fishery expert, Dr. Roldan Munoz and his recent work featured in PeerJ.
- What are bumphead parrotfish? Why are they called this?
Bumphead parrotfish (Bolbometopon muricatum) are a type of coral reef fish called a parrotfish, and they happen to be the largest species of parrotfish in the world (they can grow over 4.5 feet long and can weigh over 165 lbs). Parrotfish get their name because their teeth are fused to form a beak which they use to scrape and graze algae off the reef. Bumphead parrotfish are named due to their forehead which in adults becomes enlarged and is used by males in head-butting contests (like bighorn sheep) during fights for the chance to mate with females.
- Where are they found?
Bumphead parrotfish are found associated with coral reefs in coastal waters of the Indian and Pacific Oceans, from the Red Sea east to the Line Islands, north to Taiwan, and south to the Great Barrier Reef and New Caledonia.
- Are they rare/endangered? If so why?
Although they have a wide distribution across the Indian and Pacific oceans, in many parts of their range their populations have experienced dramatic declines and they are now rare or absent from many locations where they were once abundant. When fishing, humans tend to target the largest fish available and because of bumpheads’ large size, where they occur they are natural targets, culturally important for feasts and banquets, and highly prized. To make matters worse, bumphead parrotfish like to school in large numbers and use predictable sleeping sites in shallow waters, which makes it easy to harvest large numbers of this giant parrotfish.
- What recent research took place?
We recently studied the reproduction of bumphead parrotfish at Wake Atoll, a remote coral atoll (chain of islands formed of coral) and marine reserve under US jurisdiction in the west Pacific. The population there has been protected from fishing for decades which gave us the uncommon opportunity to study them under relatively natural conditions, with little fear of human observers. We determined that bumphead reproduction involves a large group of individuals that repeatedly visit a specific location on the reef for early morning spawning events.
- Why do we need to study them? Why do we care about reproduction of the species?
Our study is important because overfishing has apparently altered the behavior of bumphead parrotfish and led to a general avoidance of humans throughout much of their range; they are known as the wariest of parrotfishes and in most locations individuals are difficult to approach underwater. Consequently, before our work, very little information regarding reproduction was available. The study of reproduction is important for any organism because it can help scientists estimate the health of the population, so our work should provide critical insights for future conservation efforts of bumphead parrotfish.
- Why are they important to the ecosystem?
Parrotfishes as a group are a key component of coral reef ecosystems because they are often abundant and their grazing activities help keep algae in check, which can outcompete corals for space on tropical reefs. Bumphead parrotfish also feed on algae but are virtually unique on the coral reef by their consumption of large amounts of living and dead coral, which are pulverized and defecated as sand. Each individual adult has been estimated to consume over 5 tons of reef per year, so their feeding activities can affect the kinds of corals and algae growing on the reef, and the distribution of sand around the reef.
- How long have you been studying them?
I have been studying bumphead parrotfish since 2011 but have studied other parrotfishes and wrasses (a related group of reef fish) throughout my scientific career, spanning more than twenty years. In addition to their ecological importance, parrotfishes and wrasses are economically important as food fishes and are often the most commonly caught fishes where they occur.
- Where did you go to school? What did you study?
I earned a Bachelor of Science degree with a marine emphasis from the University of Maryland. I then earned a Master of Science from the University of South Florida where I studied the ecology of two species of parrotfishes in the Florida Keys. I completed a PhD at the University of California Santa Barbara and continued my work with parrotfishes and studied the reproduction of a common parrotfish on coral reefs and seagrass beds of St. Croix, US Virgin Islands.
More information on bumphead parrotfish can be found at the NOAA Fisheries Office of Protected Resources, Species of Concern website (http://www.nmfs.noaa.gov/pr/species/fish/bumpheadparrotfish.htm), as well as the IUCN website (http://www.iucnredlist.org/details/63571/0)
A full research paper, Spawning aggregation behavior and reproductive ecology of the giant bumphead parrotfish, Bolbometopon muricatum, in a remote marine reserve can was recently published and can be found at the PeerJ website: https://peerj.com/articles/681/