Structure and substratum preference of a schooling fish: observing the habitat use and nutrient input of smallmouth grunts (Haemulon chrysargyreum) in Bonaire
Various marine organisms are known to consciously select specific types of habitat that provide maximum shelter from potential predators. Reef fish such as Haemulon chrysargyreum (smallmouth grunts) are commonly seen congregating in groups around the coral structures in Bonaire. Observing schooling fish can provide pertinent information on the refuge provided by structurally complex and diverse ecosystems. This study assessed the habitat preference of H. chrysargyreum based on species of coral, complexity of sites, and substrate type. Levels of phosphate, nitrate, and ammonia were also analyzed in the areas occupied by shoaling H. chrysargyreum to see if they provide a significant input of nutrients into the coral reef ecosystem. The results of this study demonstrate that H. chrysargyreum prefer areas of medium to high complexity accompanied with a soft substrate (sand, rubble) and an overhanging structure. Nutrient level analysis was inconclusive and, therefore, requires further studies. This research sought to identify certain species of coral and structures that are used by H. chrysargyreum for habitation. Such knowledge can aid conservation efforts by honing in on specific areas that schooling fish utilize for shoaling and feeding. Additionally, data from this study provided preliminary assessment for future studies on the potential nutrient input of H. chrysargyreum to the marine ecosystem.
This student research was retrieved from Physis: Journal of Marine Science XIX (Spring 2016)19: 52-63 from CIEE Bonaire.