Reef Fish Life History
Roi (Cephalopholis argus)
The peacock grouper, Cephalopholis argus, locally known in Hawai‘i as roi, was introduced from French Polynesia in the 1950s. This intentional introduction was designed to enhance nearshore fisheries in Hawa‘i, however, roi has not become a preferred target species due to high incidence of ciguatera fish poisoning. Roi populations have become established across the state of Hawai‘i, yet little is known about the biology in either the native or introduced range. Efforts from past and current members of the Fisheries Ecology Research Lab have been to understand roi’s role in Hawaii’s ecosystem, and assess the life history of roi for population modeling. My master’s thesis was on the age and growth of roi populations at 10 locations across the main Hawaiian Islands. Additionally, in collaboration with Jonatha Giddens and TNC, I have helped to assess the best ways to measure roi abundance, and to conduct a long-term removal experiment. In collaboration with Eva Schemmel I have also helped study the reproductive biology of roi.
Collaborators: Jonatha Giddens, Eva Schemmel, Chad Wiggens, Alan Friedlander
Oio (Albula spp.)
Collaborators: Eva Schemmel, Keith Kamikawa, Alan Friedlander
Bonefishes, locally known in Hawai‘i as oio, are an important food fish and also have cultural and recreational value. Two distinct species inhabit Hawaiian waters including an endemic (Albula virgata), and a widespread species (A. glossodonta). Previously, little was known about the life history of these two species, hindering population assessments and fisheries management. We assessed differences in size, abundance, diet, growth, reproduction and habitat preferences of each species to help explain the coexistence of the two closely related species and to aid in management. We found important differences in their life histories that differentiate the two species ecologically and are necessary for developing species-specific management strategies.
Collaborators: Whitney Goodell, Edward DeMartini, Alan Friedlander
Length-weight relationships in fishes are central to understanding the status and condition of populations, and are critical for estimating biomass from length observations. Yet this information isn’t always available for every species, especially given that these parameters can vary spatially and temporally within a given species, requiring specific parameters for unique locations. Many Hawaiian reef fishes are endemic, and Hawaii has a unique geography, so length-weight parameters for these species in particular are needed. I’ve worked with my colleagues to develop a comprehensive database of existing length and weight data for nearshore reef fish species in Hawaii including a collection of fishes held by the Hawaii Cooperative Fishery Research Unit dating back to 1980. Large collections were made in the early 1980s in both the Main and Northwestern Hawaiian islands allowing for interesting comparisons with more recent collections.