Insight into Seasonal Recruitment Dynamics of Juvenile Mulloidichthys vanicolensis and M. Flavolineatus

Abstract

Goatfish were a culturally important food resource for early Hawaiians and their value is still sustained today as one of the highly sought reef fish in Hawaii’s recreational and commercial fisheries. The most common juvenile goatfishes (oama), Mulloidichthys flavolineatus and M. vanicolensis, exhibit an annual pulse-type recruitment to near shore areas during the summer months in the Main Hawaiian Islands. These annual recruitment events provide food for pelagic and near shore fish as well as food and sport for recreational anglers. Growth rate, habitat preference, hatch date, CPUE, and size and age structure were used to compare recruitment characteristics between species, locations, and years. Oama during 2015 grew faster, were heavier on average, and hatched later than fish during the anomalously high 2014 recruitment. During a typical year, M. vanicolensis recruit earlier than M. flavolineatus and each species is directly linked with a hard or soft substrate type respectively. Limited information exists on these juvenile fishes even though these species have a significant role in the coastal ecology and near shore fisheries. This project aims to shed light on the early life history settlement characteristics of these goatfishes through the study of their annual recruitment patterns.