Multivariate Statistical Analysis for Global Mid Ocean Ridge Hydrothermal Vents

Hydrothermal vents are abundant along the global mid-ocean ridge (MOR) network and are associated with unique animal communities. We created a new database of 439 individual hydrothermal vents belonging to 73 vent fields at global divergent margins using published and on-line information for all available MOR hydrothermal fluids and biota. We carried out multivariate statistical analysis of vent fluid parameters and similarity analysis for vent biota. Sorensen similarity analysis show that similarity between MOR vent biota is independent of the ocean. The fluid parameters were assessed to explore correlations against the spreading rate, vent depth, venting fluid temperature, pH and chloride ion concentration. Our results indicate that none of these fluid parameters show good correlations (τ > 0.8) to the spreading rate, vent depth, venting fluid temperature, pH and chloride ion concentration. Furthermore, the ridge segments were assessed for statistically significant differences based on the vent fluid parameters using rank-based non-parametric Analysis of Variance (ANOVA) with Bonferroni adjustment. Vent fluid parameters show both similarities (e.g., temperature between East Pacific Rise (EPR) vs Galapagos Spreading Center, Mid Atlantic Ridge) and differences (e.g., temperature between EPR vs Explorer Ridge and Juan de Fuca Ridge) between the ridges regardless of the ocean. Overall, the data show that even if MOR hydrothermal systems are associated with simple divergent margin tectonism, they have differences in both fluid chemistry and biota distribution regardless of the ocean and the rate of spreading.