A Systematic Literature Review of the Methodology Preference for Analyzing Eel (Anguilla spp.) Habitat

Indonesia is rich in eel (Anguilla spp.) fishery resources, however, only sparse information is available regarding these resources, particularly the habitat preferences. These preferences have been studied severally using different methods, thus, there is currently no comprehensive description of the exact study methods. This study, therefore, aims to assay the development of research on eel habitat in the tropics, especially in Indonesia, and discover the most prevalent study method used between 2001 and 2020. This was carried out using a systematic literature review, defined as the process of identifying, assessing, and interpreting all available research evidence to provide answers to specific research questions. A total of 21 studies were selected for further analysis based on the specified inclusion and exclusion criteria. According to the results, current studies on eel habitat preferences focus on three topics: the ecology and behavior of eels during their lifecycle (52%), the relationship between eel morphology and habitat (19%), as well as the relationship between the time of metamorphosis and habitat (29%). Furthermore, 4 methods: Bio-morphology (29%), Otolith (57%), Ecological Studies (10%), and Gonadosomathic Index (5%), are commonly used. However, researchers suggest future research ought to be conducted more comprehensively. Therefore, more detailed ecological studies need to be carried out, together with otolith and bio-morphological studies.