The Galapagos marine ecosystem supports several valuable fisheries (e.g., groupers, snappers, lobster), and a unique, diverse community of tropical and temperate species. To better manage these resources, data are needed on age-specific habitat associations for key fishery species. Mangroves, an assemblage of woody, salt-tolerant plants, are important foundation species in shallow marine ecosystems. Mangrove forests support productive food webs via the provision of structurally complex habitat for a wide variety of flora and fauna. Moreover, mangroves may function as nursery and feeding grounds for many commercially valuable fishes. Despite a general appreciation for the importance of high-quality habitat in promoting healthy fisheries throughout the Galapagos Archipelago, there remains a general lack of data on habitat-specific fish density, growth or movement patterns. In June 2013, we established 12 Vemco VR2W acoustic omni-directional hydrophone stations in two mangrove creek systems on the south coast of Isabela Island. Tagged snapper showed trends of utilizing the middle and upper regions of the mangrove creeks more heavily than the lower portion of creek habitats. Additionally we conducted a number of visual transect suveys to document relative densities and sizes of fishes between mangrove (divided among 'creek interior', creek mouth', and mangrove edge') and non mangrove sites. Results suggest that creek systems within the island of isabella serve as primary habitat for juvenile snapper species. Data on snapper and grouper movement and growth/diet within and near mangroves will help resource managers manage marine resources in the Galapagos National Park. 

 

Funding Sources: UNC Chapel Hill Center for Galapagos Studies

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Collaborators: Joel Fodrie*, Rachel Gittman*, Danielle Keller*, Matthew Kenworthy*

     *Project PI