@article {ISI:000321177000006,
	title = {{Active positioning of vent larvae at a mid-ocean ridge}},
	journal = {DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY},
	volume = {92},
	number = {SI},
	year = {2013},
	month = {aug},
	pages = {46{\textendash}57},
	type = {Article},
	abstract = {The vertical position of larvae of vent species above a mid-ocean ridge potentially has a strong effect on their dispersal. Larvae may be advected upward in the buoyant vent plume, or move as a consequence of their buoyancy or by active swimming. Alternatively, they may be retained near the bottom by the topography of the axial trough, or by downward swimming. At vents near 9 degrees 50{\textquoteright}N on the axis of the East Pacific Rise, evidence for active larval positioning was detected in a comparison between field observations of larvae in the plankton in 2006 and 2007 and distributions of non-swimming larvae in a two-dimensional bio-physical model. In the field, few vent larvae were collected at the level of the neutrally buoyant plume (similar to 75 m above the bottom); their relative abundances at that height were much lower than those of simulated larvae from a near-bottom release in the model. This discrepancy was observed for many vent species, particularly gastropods, suggesting that they may actively remain near the bottom by sinking or swimming downward. Near the seafloor, larval abundance decreased from the ridge axis to 1000 m off axis much more strongly in the observations than in the simulations, again pointing to behavior as a potential regulator of larval transport. We suspect that transport off axis was reduced by downward-moving behavior, which positioned larvae into locations where they were isolated from cross-ridge currents by seafloor topography, such as the walls of the axial valley which are not resolved in the model. Cross-ridge gradients in larval abundance varied between gastropods and polychaetes, indicating that behavior may vary between taxonomic groups, and possibly between species. These results suggest that behaviorally mediated retention of vent larvae may be common, even for species that have a long planktonic larval duration and are capable of long-distance dispersal. (C) 2013 Elsevier Ltd. All rights reserved.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0967-0645},
	doi = {10.1016/j.dsr2.2013.03.032},
	author = {Mullineaux, L S and McGillicuddy Jr., D J and Mills, S W and Kosnyrev, V K and Thurnherr, A M and Ledwell, J R and Lavelle, J W}
}
@article {Jackson2010,
	title = {{Dispersion of a tracer on the East Pacific Rise (9 degrees N{\textendash}10 degrees N), including the influence of hydrothermal plumes}},
	journal = {Deep-Sea Research. Part I: Oceanographic Research Papers},
	volume = {57},
	number = {1},
	year = {2010},
	pages = {37{\textendash}52},
	abstract = {On 12 November 2006, 3 kg of sulfur hexafluoride were released in a 1.2 km long streak in the axial summit trough of the East Pacific Rise at 9{\textdegree}30'N to study how circulation and mixing affect larval dispersion. The first half of a tracer survey performed approximately 40 days after the injection found a small percentage of the tracer on the ridge axis between 9{\textdegree}30'N and 10{\textdegree}10'N, with the main concentration near 9{\textdegree}50'N, a site of many active hydrothermal vents. These observations provide evidence of larval connectivity between vent sites on the ridge. The latter half of the survey detected the primary patch of tracer west of the ridge and just south of the Lamont Seamounts, as a majority of the tracer had been transported off the ridge. However, by the end of the survey, the eastern edge of this patch was transported back to within 10 km of the ridge crest at 9{\textdegree}50'N by a reversal in the subinertial flow, suggesting another pathway for larvae between points along the ridge. Both the horizontal and vertical distributions of the tracer were complex and were likely heavily influenced by topography and vents in the area. Elevated tracer concentrations within the axial summit trough and an adjacent depression on the upper ridge flank suggest that tracers may be detained in such depressions. Correlated tracer/turbidity profiles provide direct evidence of entrainment of the tracer into vent plumes from 9{\textdegree}30'N to 10{\textdegree}N. A comparison of the vertical tracer inventory with neutral density vent-plume observations suggests that on the order of 10{\%} of the tracer injected was entrained into vent plumes near the injection site. The results imply that effluent from diffuse hydrothermal sources and larvae of hydrothermal vent fauna can be entrained in significant quantities into plumes from discrete sources and dispersed in the neutrally buoyant plumes.},
	keywords = {HOV Alvin (Human Occupied Vehicle)},
	issn = {0967-0637},
	doi = {10.1016/j.dsr.2009.10.011},
	url = {http://dx.doi.org/10.1016/j.dsr.2009.10.011},
	author = {Jackson, P R and Ledwell, J R and Thurnherr, A M}
}
