Development and Use of Genetic Methods for Assessing Aquatic Environmental Condition and Recruitment Dynamics of Native Stream Fishes on Pacific Islands
Abstract
The overall objective of this project was to develop and demonstrate genetic approaches for assessing the condition (i.e., integrity) of Pacific island watersheds. Traditional assemblage-based protocols provide little basis for discrimination because the biota of Pacific island streams is naturally depauperate and tightly linked to oceanic environments. Genetic assessment protocols can be more effective tools for quantifying watershed condition because genetic analyses can reveal how environmental stressors influence individuals and populations. However, developing and implementing genetic assessment approaches for Pacific island watersheds requires more thorough knowledge of the demographic and ecological processesespecially dispersal and sensitivity to environmental stressors- that give rise to patterns of genetic variation within species that serve as biotic indicators. We undertook a suite of studies focusing on native amphidromous fishes of the Hawaiian Islands to support the development and use of genetic approaches for assessing the integrity of Pacific island watersheds. In the first study, we examined the historical biogeography and contemporary dispersal of native amphidromous fishes across the Hawaiian archipelago. Amphidromy is a form of diadromy, where adults inhabit and spawn in freshwater, larvae drift downstream to near-shore or oceanic environments where they mature for periods of up to six months, after which they recruit back to freshwater streams as postlarvae. The specific objectives of this study were to (1) determine whether different islands harbor distinct evolutionary lineages; and through a multi-disciplinary approach (2) determine whether local recruitment draws from mixed immigrant pools due to larval exchange across the archipelago. This work was intended to help identify the most appropriate spatial scale for management of native fishes and stream ecosystems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2014
- Accession Number
- ADA607042
Entities
People
- James F. Gilliam
- Michael J Blum
- Peter B. Mcintyre
Organizations
- Tulane University of Louisiana