Community study of tubeworm-associated epizooic meiobenthos from deep-sea cold seeps and hot vents

Abstract

The permanent metazoan meiofauna associated with vestimentiferan tubeworm aggregations from hydrocarbon seeps of the upper Louisiana slope in the Green Canyon (~550 m) and the lower slope in Atwater Valley (~2200 m) of the Gulf of Mexico was characterized. Meiofauna abundance, diversity, and community composition at genus level were compared between these seep sites, and with those of tubeworms from hydrothermal vents of the East Pacific Rise (Gollner et al. 2007; Mar Ecol Prog Ser 337:39-49). The abundance was not significantly different between the 2 seep sites, and was also similar to those found at vents. A total of 150 meiobenthic genera were identified from the cold seep sites. While no significant difference in univariate measurements of diversity was detected, a shift in community composition between the shallow and the deep seep site was found. The hot vent communities included a total of only 17 genera and the diversity measurements were significantly lower at vents than at seeps. Also, Bray-Curtis dissimilarity was 97% between the meiobenthic communities from seeps and vents. The genera richness was negatively correlated with maximum temperature and maximum sulfide concentration, and positively correlated with minimum pH value. We conclude that the harsh conditions tubeworms experience at vents compared to the moderate conditions at cold seeps, as well as the longevity of cold seeps surrounded by sedimented deep-sea plains but short-lived vents on basaltic mid-ocean ridges, might explain the contrasting diversity patterns.KEY WORDS: Meiobenthos · Meiofauna · Cold seep · Hydrothermal vent · Community study · Biodiversity · Vestimentiferans · Gulf of Mexico Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 468: [135][136][137][138][139][140][141][142][143][144][145][146][147][148] 2012 vestimentiferans (Polychaeta, Siboglinidae) create complex secondary structures that serve as a living space for a variety of associated species (Bright & Lallier 2010).Symbiont-housing foundation species from cold seeps of the Gulf of Mexico have been studied extensively (Levin 2005, Cordes et al. 2009). The cold seep sites on the upper Louisiana slope (<1000 m depth) in the Gulf of Mexico are colonized by 3 species of vestimentiferan tubeworms: Lamellibrachia luymesi van der Land & Nørrevang, 1975; Seepiophila jonesi Gardiner, McMullin & Fischer, 2001; and a still undescribed species of escarpids (McMullin 2003). On the lower slope (>1000 m depth), Escarpia laminata Jones, 1985 and 2 still undescribed species of lamellibrachids (see Cordes et al. 2009) are found.Hundreds to thousands of individuals of Seepiophila jonesi co-occurring with Lamellibrachia luymesi form bush-like aggregations several meters in diameter and sometimes over 2 m in height on the upper slope (Bergquist et al. 2002). Conservative age estimates of L. luymesi are well over 100 years, with the upper limit of age still unknown (Fisher et al. 1997, Bergquist et al. 2000, Cordes et al. 2005b)....

Characteristics of meiofauna in extreme marine ecosystems: a review

“…In recent years, the deep-sea hydrothermal vent meiofauna has increasingly gained interest and several studies have been published (Vanreusel et al 1997;Tsurumi et al 2003;Zekely et al 2006a, b;Copley et al 2007;Gollner et al 2007Gollner et al , 2010bGollner et al , 2013Limén et al 2007;Degen et al 2012;Cuvelier et al 2014;Sarrazin et al 2015). Meiofauna is considered to contribute up to 20% of the total diversity known from deep-sea hydrothermal vents (Bright 2006).…”

“…The picture emerging from these studies points to a vent meiofauna with low abundance and diversity (Dinet et al 1988;Vanreusel et al 1997;Tsurumi et al 2003;Copley et al 2007;Limén et al 2007;Gollner et al 2010b) compared with other chemosynthetic ecosystems characterised by less extreme conditions. Their distributions vary with the abiotic conditions of the habitat (Gollner et al 2010b;Sarrazin et al 2015) and the presence of bacterial mats and large engineer species, such as mussels and tubeworms (Zekely et al 2006a, c;Gollner et al 2010b;Degen et al 2012). In the Atlantic, meiofauna represent at least 50% of the total diversity in vent fauna and meiofaunal communities are dominated by generalist nematodes and endemic copepods (Zekely et al 2006a, c;Sarrazin et al 2015).…”

Rapid colonisation by nematodes on organic and inorganic substrata deployed at the deep-sea Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge)

“…Several HV habitats, from inactive bare basalts (Gollner et al 2010b) and sediments (Vanreusel et al 1997) to diffuse flow areas colonized by macrofaunal assemblages (Zekely et al 2006a, c), host meiofaunal communities characterized by low abundance and diversity, linked with the abiotic and biotic conditions of the habitat (Gollner et al 2010b;Zekely et al 2006a, c;Degen et al 2012). In most cases, nematodes and copepods are the most abundant meiofaunal organisms (Vanreusel et al 2010;Zeppilli et al submitted).…”

Copepod colonization of organic and inorganic substrata at a deep-sea hydrothermal vent site on the Mid-Atlantic Ridge

“…The symbiont hosting vent megafauna can serve as ecosystem engineers, providing living space for a variety of smaller macro-and meiofaunal organisms which also rely on chemoautotrophic symbionts or directly feed on free-living microorganisms and other organic material (Levesque et al 2003, Govenar et al 2005, Gollner et al 2006, Limén et al 2008, Pradillon et al 2009, Degen et al 2012. The distribution and composition of these biological assemblages can be strongly influenced by changes in physico-chemical conditions at hydrothermal vents, depending on species-specific physiological tolerance to fluid chemistry and nutritional requirements (Sarrazin et al 2015).…”

“…According to these studies, the meiofauna can make up to 50 % of total local diversity at a hydrothermal vent site. However, vent meiofaunal communities often show low diversity and densities compared to the surrounding deep-sea sediments (Degen et al 2012). Their composition and abundance can be correlated with the abiotic and biotic conditions of the local microhabitats (Ivanenko et al 2011, Ivanenko et al 2012, Sarrazin et al 2015.…”