Community Structure of Macrobiota and Environmental Parameters in Shallow Water Hydrothermal Vents off Kueishan Island, Taiwan

Abstract

Hydrothermal vents represent a unique habitat in the marine ecosystem characterized with high water temperature and toxic acidic chemistry. Vents are distributed at depths ranging from a few meters to several thousand meters. The biological communities of shallow-water vents have, however, been insufficiently studied in most biogeographic areas. We attempted to characterize the macrofauna and macroflora community inhabiting the shallow-water vents off Kueishan Island, Taiwan, to identify the main abiotic factors shaping the community structure and the species distribution. We determined that positively buoyant vent fluid exhibits a more pronounced negative impact to species on the surface water than on the bottom layer. Species richness increased with horizontal distance from the vent, and continuing for a distance of 2000 m, indicating that the vent fluid may exert a negative impact over several kilometers. The community structure off Kueishan Island displayed numerous transitions along the horizontal gradient, which were broadly congruent with changes in environmental conditions. Combination of variation in Ca2+, Cl-, temperature, pH and depth were revealed to show the strongest correlation with the change in benthic community structure, suggesting multiple factors of vent fluid were influencing the associated fauna. Only the vent crabs of Kueishan Island may have an obligated relationship with vents and inhabit the vent mouths because other fauna found nearby are opportunistic taxa that are more tolerant to acidic and toxic environments.

Holocene benthic foraminiferal and ostracod assemblages in a paleo-hydrothermal vent system of Campi Flegrei (Campania, South Italy)

“…Shallow marine hydrothermal vent systems are frequently characterized by biota, such as nematodes and polychaetes, devoid of easily fossilizable parts, able to live in extreme ecological conditions where macrofauna is not present (Kamenev et al, 1993;Hoaki et al, 1995). As a general rule in the vicinity of the vent outlets the diversity decreases, the dominance of tolerant spe-cies increases (Melwani and Kim, 2008;Zeppilli and Danovaro, 2009;Karlen et al, 2010;Chan et al, 2016) and the bottom waters are frequently corrosive to calcium carbonate inhibiting the calcification of shelled organisms (Cigliano et al, 2010;Ricevuto et al, 2012;Boatta et al, 2013).…”

Influences of geothermal sulfur bacteria on a tropical coastal food web

“…At upper bathyal depths, inputs from photosynthetic organisms increase and dependence on chemosynthetic carbon would proportionally decrease (Levin & Michener 2002, Levin 2005, Levin & Mendoza 2007. In shallow vents the major food source is usually photosynthetic rather that chemosynthetic (Kharlamenko et al 1995, Tarasov et al 2005, Chan et al 2016. However, despite this lower relative abundance of sulfur bacteria, they can still be used as food source in some shallow vent locations (Thiermann et al 1997, Bosley et al 2002, Forrest 2004, Comeault et al 2010).…”

Distribution and sexual dimorphism of the crab Xenograpsus testudinatus from the hydrothermal vent field of Kueishan Island, northeastern Taiwan

“…Previous studies showed that hydrothermal vents are the most important habitat factor for the vent crab X. testudinatus. This crab could not be found otherwise along the shallow coast of Kueishan Island outside the hydrothermal vent area [18]. The main reason might be the acidity and sulfide toxicity of hydrothermal vent waters that made it impossible for the predators of X. testudinatus living in hydrothermal vent field for extended times.…”

“…The M. distinguendus may slowly evolve detoxification mechanisms against toxic hydrothermal vent waters that expand its habitat into this area. On the other hand, Xenograpsus testudinatus highly rely on toxic hydrothermal vent waters [18], Fig 7. A survey of the distribution of female and male morphological measurements for the all crabs, wet body weight (a), carapace width (b), and chela length (c).…”

“…The hydrothermal vent water is toxic because it is rich of sulfides among other natural compounds [11,12]. In such a special environment, a variety of highly adapted organisms occur, such as the crab Macromedaeus distinguendus (De Haan, 1835) [13] and Xenograpsus testudinatus N. K. Ng, J.-F. Huang & Ho, 2000 [14], copepods [15][16], anemones [17][18], several species of mollusks [17][18][19][20], and the azooxanthellate scleractinian coral Tubastrea spp. [17].…”