TY - JOUR
T1 - Distribution of diffuse flow megafauna in two sites on the Eastern Lau Spreading Center, Tonga
AU - Podowski, Elizabeth L.
AU - Moore, Tom S.
AU - Zelnio, Kevin A.
AU - Luther, George W.
AU - Fisher, Charles R.
N1 - Funding Information:
This project was funded by NSF grants OCE-0240985 to CRF and S. Hourdez and OCE-0240896 to GWL III. None of this work would have been possible without the expertise and patience of the ROV JASON II and R/V Melville crews. Valuable data and insight were provided by the scientific parties that participated in the RIDGE 2000 Lau Basin cruise series. We also thank Fernando Martinez, Charlie Langmuir, Ken Takai, Meg Tivey, Jim Childress, and Mike Henry for selflessly sharing their data before publication. In addition, we thank S. Kim for training in mosaicking techniques, Denice Wardrop and Jim Sloan for essential GIS counseling and support, and Iliana Baums, Kate Mullaugh, Erin Becker, and Stephanie Lessard-Pilon for their comments on earlier versions of the manuscript.
PY - 2009/11
Y1 - 2009/11
N2 - Hydrothermal vent environments are characterized by large gradients of toxic chemicals and high temperatures, which play a significant role in defining species' distributions. We used high-resolution imagery and spatially explicit in-situ physico-chemical measurements analyzed within a Geographic Information System (GIS) in order to characterize the spatial relations among different groups of megafauna, temperature, and chemistry within two discrete vent communities (40 and 50 m2) on the Eastern Lau Spreading Center (ELSC). Chemical (sulfide and O2 concentrations) and temperature data were obtained from approximately 75 different locations within each community using in-situ instruments. All data were integrated into a GIS, which served as a visualization tool and enabled the data to be analyzed in a spatial context. Our results confirm the importance of abiotic variables in defining the distributions of some fauna and elucidate several biological associations that are consistent between the two communities. The provannid snail, Alviniconcha spp., appears to actively avoid temperatures above 32-46 °C and/or sulfide concentrations exceeding approximately 260 μM. Slightly higher average sulfide concentrations and temperatures were measured among aggregations of Ifremeria nautilei compared to aggregations of the mussel Bathymodiolus brevior; however, the presence of mixed aggregations of the two species indicates an overlap in requirements. The brachyuran crab, Austinograea spp., was consistently observed directly on symbiont-containing species, particularly Alviniconcha spp. The solitary snail, Eosipho desbruyeresi, was rarely observed on biological substrata, but was often (60% of its population at the most active site) within 5 cm of symbiont-containing fauna, indicating a tolerance and preference for proximity to areas of high productivity. Densities and coverage of species differed substantially between the two communities despite high species overlap. Symbiont-containing species covered much larger areas at the more hydrothermally active site, ABE1, while shrimp and anemones occurred in relatively higher densities within the less-active site, TM1. This is the first study to thoroughly characterize realized distributions of megafauna at vent sites along the ELSC.
AB - Hydrothermal vent environments are characterized by large gradients of toxic chemicals and high temperatures, which play a significant role in defining species' distributions. We used high-resolution imagery and spatially explicit in-situ physico-chemical measurements analyzed within a Geographic Information System (GIS) in order to characterize the spatial relations among different groups of megafauna, temperature, and chemistry within two discrete vent communities (40 and 50 m2) on the Eastern Lau Spreading Center (ELSC). Chemical (sulfide and O2 concentrations) and temperature data were obtained from approximately 75 different locations within each community using in-situ instruments. All data were integrated into a GIS, which served as a visualization tool and enabled the data to be analyzed in a spatial context. Our results confirm the importance of abiotic variables in defining the distributions of some fauna and elucidate several biological associations that are consistent between the two communities. The provannid snail, Alviniconcha spp., appears to actively avoid temperatures above 32-46 °C and/or sulfide concentrations exceeding approximately 260 μM. Slightly higher average sulfide concentrations and temperatures were measured among aggregations of Ifremeria nautilei compared to aggregations of the mussel Bathymodiolus brevior; however, the presence of mixed aggregations of the two species indicates an overlap in requirements. The brachyuran crab, Austinograea spp., was consistently observed directly on symbiont-containing species, particularly Alviniconcha spp. The solitary snail, Eosipho desbruyeresi, was rarely observed on biological substrata, but was often (60% of its population at the most active site) within 5 cm of symbiont-containing fauna, indicating a tolerance and preference for proximity to areas of high productivity. Densities and coverage of species differed substantially between the two communities despite high species overlap. Symbiont-containing species covered much larger areas at the more hydrothermally active site, ABE1, while shrimp and anemones occurred in relatively higher densities within the less-active site, TM1. This is the first study to thoroughly characterize realized distributions of megafauna at vent sites along the ELSC.
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U2 - 10.1016/j.dsr.2009.07.002
DO - 10.1016/j.dsr.2009.07.002
M3 - Article
AN - SCOPUS:71749120767
SN - 0967-0637
VL - 56
SP - 2041
EP - 2056
JO - Deep-Sea Research Part I: Oceanographic Research Papers
JF - Deep-Sea Research Part I: Oceanographic Research Papers
IS - 11
ER -
