| dc.description | Variations in early life-history stages of benthic marine invertebrates can have profound effects on the dynamics and persistence of adult populations. At deep-sea hydrothermal vents, successful settlement and recruitment are thought to be crucial to the connectivity and persistence of invertebrate populations in these patchy and ephemeral habitats. For this thesis research, I designed quantitative experiments to measure the spatial and temporal variation in colonization by hydrothermal vent invertebrates on the Juan de Fuca Ridge in the Northeast Pacific, and identify biotic and abiotic factors that affect the early life-history stages. My results demonstrate that settlement and colonization are regulated primarily by responses of vent species to variations in vent fluid properties, and secondarily by biological interactions. While harsh properties of the venting fluid may limit colonization by vent species, complex physical substrates promote the diversity and richness of colonist assemblages. I focussed on the most abundant species, Lepetodrilus fucensis, at hydrothermal vents on the Juan de Fuca Ridge, to assess the impact of variation in early life-history traits (growth, mortality, reproduction) on adult abundance and population structure. Variations in hydrothermal fluid flow, and infection by a copepod parasite, impacted the reproductive output of L. fucensis. High post-settlement mortality of L. fucensis resulted in low but continual recruitment of individuals into the adult population. Results of a stage-based population model erected for L. fucensis confirmed that variation in the survival and growth of settlers and recruits have the greatest impact on its population dynamics. Overall, the results of this thesis demonstrate that the physico-chemical properties of hydrothermal vents, as well as biological factors, can influence the abundance and distribution of early life-history stages of vent species, and that these variations can influence the dynamics and persistence of adult populations at deep-sea hydrothermal vents on the Juan de Fuca Ridge, Northeast Pacific. | en_US |
