Characteristics of a hydrothermal vent assemblage on a volcanically active segment of Juan de Fuca Ridge, northeast Pacific

Abstract

An eruption on Cleft segment, Juan de Fuca Ridge, in 1986 provided an opportunity to observe potential successional patterns in vent-animal colonisation. Other objectives were to describe the Cleft fauna, examine the distribution and abundance of selected taxa, and determine if the fauna reflected changes in water chemistry. Biological samples were tubeworm grabs collected by submersible, and visual data were still photographs and videos. Two years post eruption, there were extensive diffuse vents and 23 of the 44 species constituting the Cleft species pool were present. Five years post eruption, most low-temperature vents were extinct. High-temperature venting was maintained, and biological communities were reduced in visual extent. Four of the 44 species in samples from 1988-1994 accounted for over 90% of the individuals. Cluster analyses of species collected on tubes did not distinguish year or substratum differences, suggesting that a study of less than a year is necessary to document successional patterns at new vents. The Cleft subset of the Juan de Fuca Ridge species pool is likely adapted to episodic eruptive events on the decadal scale. Major changes in fluid chemistry did not result in detectable community changes other than habitat loss due to a decrease in dissolved sulphide availability.Résumé : Une éruption sur la section Cleft de la dorsale Juan de Fuca en 1986 nous a permis d'observer les patterns potentiels de succession dans la colonisation par la faune des cheminées hydrothermales. Nos objectifs secondaires sont de décrire la faune de la section Cleft, d'étudier la répartition et la composition de taxons particuliers et d'établir si les changements faunistiques reflètent les variations dans la chimie de l'eau. Les données biologiques consistent en des récoltes de vers tubicoles à la benne réalisées par submersible et les données visuelles en des photographies et des films vidéo. Deux ans après l'éruption, il y avait un grand nombre de cheminées diffuses et 23 des 44 espèces du pool d'espèces de la section Cleft étaient présentes. Cinq ans après l'éruption, la plupart des cheminées à basse température étaient inactives. Il y avait des cheminées à haute température et, visuellement, les communautés biologiques y étaient réduites. Quatre des 44 espèces récoltées de 1988 à 1994 représentent plus de 90% de la densité totale. Des analyses de groupement des espèces récoltées sur les tubes ne permettent de distinguer ni les années ni les substrats, ce qui laisse croire qu'une étude au cours de la première année est nécessaire pour suivre la succession sur les nouvelles cheminées. Le sous-groupe d'espèces de la section Cleft du pool d'espèces de la dorsale Juan de Fuca est sans doute adapté à des éruptions sporadiques à une échelle de quelques dizaines d'années. Les variations importantes dans la chimie des fluides n'ont pas généré de changements décelables dans la communauté autres que des pertes d'habitat causées par une baisse de la disponibilité des sulfures dissous.[Traduit par la Rédaction] Tsurum...

Community dynamics over 14 years at the Eiffel Tower hydrothermal edifice on the Mid‐Atlantic Ridge

“…As clustering occurs according to the orientation of the edifice, not according to the years, the characteristics inherent to the sides and their orientation seem to be more important in determining faunal occupation. Similar patterns were described at JdF Ridge, where vent sites investigated between 1988 and 1994 did not cluster by year either, nor by geographic locality (Tsurumi and Tunnicliffe 2001). Instead, local habitat-scale features were the determinants in explaining species distribution patterns.…”

“…Many recent discoveries of hydrothermal venting have taken place in the South Atlantic, Arctic, West Pacific, and Indian Oceans, but time-series studies remain scarce and are restricted to several well-known and more accessible sites mainly situated in the East Pacific Ocean. Ecological time-series studies have been carried out under conditions of continuous venting on the Galá pagos Rift (Hessler et al 1985(Hessler et al , 1988, the East Pacific Rise (EPR; Fustec et al 1987;Desbruyères 1998), the Juan de Fuca Ridge (JdF; Sarrazin et al 1997), and in some cases, monitoring started right after or during an eruption (9.5uN, EPR: Shank et al 1998;Nees et al 2008;JdF: Tunnicliffe et al 1997;Tsurumi and Tunnicliffe 2001;Marcus et al 2009; Galá pagos Rift: Shank et al 2003). Each of these studies attempts to disentangle community dynamics and assess or propose a succession model.…”

Exploring the Ecology of Deep-Sea Hydrothermal Vents in a Metacommunity Framework

“…Notably, during the short observation periods after the eruptions in both Pacific regions, death of foundation species in small aggregations resulted from cessation of vent flow. These observations point to the high temporal variability of venting and community structure on faster-spreading centers (Tsurumi and Tunnicliffe, 2001;Gollner et al, 2013;Klose et al, 2015; described further in section Global Patterns of Vent Distributions, Disturbance Frequency and Longevity; Figure 3). …”

Picturing thermal niches and biomass of hydrothermal vent species

“…Vent communities are often dominated by invertebrates living in association with symbionts (Léveillé et al, 2005) such as siboglinid tubeworms in the Pacific and bathymodiolin mussels or bresiliid shrimp in the Mid-Atlantic Ridge (MAR), which aggregate in patches (e.g. Tsurumi and Tunnicliffe, 2001). However, much is still unknown about what determines the success of these species and the factors behind the distribution of their associated communities.…”