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Crowe, S.E.; Bergquist, D.C.; Sanger, D.M., and Van Dolah, R.F., 2016. Physical and biological alterations following dredging in two beach nourishment borrow areas in South Carolina's coastal zone. Dredging of nearshore subtidal sand deposits as a source for beach fill is a common practice in the SE United States, but the long-term effects of this practice on benthic environments are not well documented. Two borrow areas used to nourish the shoreface of Folly Beach, South Carolina, in 2005 (borrow area A) and 2007 (borrow area B) were sampled for sediment characteristics (silt and clay, calcium carbonate, total organic matter content, and sand phi size) and macrobenthic infaunal community composition using a before–after, control–impact design over periods of 8 and 6 years postdredging, respectively. Following dredging, surficial sediment characteristics within both borrow pits shifted toward finer materials and showed little evidence of recovering 8 and 6 years after impact. Changes in the benth...

The Ashepoo-Combahee-Edisto (ACE) Basin (South Carolina, USA) National Estuarine Research Reserve System (NERRS) encompasses some of the least developed USA coastline. Yet, periodic sampling showed that certain regions have higher nutrient, fecal coliform, and chlorophyll a levels, often with lower dissolved oxygen, than other South Carolina estuaries. To evaluate the spatial extent of these issues, a summer (2008) baseline study was conducted. Physical water quality, total nitrogen and phosphorus, chlorophyll a, dissolved organic carbon, and suspended solids were measured from surface waters of 67 stations (30 tidal creek, 37 open water). Nutrient and chlorophyll a levels were significantly (p

Unexplained and episodic die-offs of the dwarf surf clam, Mulinia lateralis , have been reported on the West Atlantic coast, with such an occurrence in South Carolina in June 2010. A sample of live clams from the 2010 South Carolina event was collected, and 200 clams were measured and necropsied. Two species of tapeworm larvae were observed. Plerocercoids (Duplicibothrium sp.) occupied the digestive gland ducts, and merocercoids (Rhodobothrium sp.) were found beneath the mantle. Specimens of both species were sequenced to obtain partial 28S rRNA gene sequences, and they were identified as the tetraphyllidean D. minutum and the rhinebothriidean R. paucitesticulare, based on an NCBI Standard Nucleotide BLAST search. Of the 200 clams, 2.1% were infected with merocercoids (mean intensity 1.3 ± 0.2) and 75% with plerocercoids (mean intensity 4.3 ± 3.7). Intensity of infection by plerocercoids increased significantly with individual shell length. The presence of plerocercoids was associated with enlargement of the digestive gland ducts, but no other pathology was observed. Because uninfected clams were abundant among the stranded molluscs, these parasites are not considered to be the causative agent of the die-off. This is a new host record for both elasmobranch tapeworms.

The deepening of shipping and entrance channels in Charleston Harbor (South Carolina, USA) was completed in April 2002 and placed an estimated 22 million cubic yards (mcy) of material in the offshore Charleston Ocean Dredged Material Disposal Site (ODMDS). To determine if sediments dispersed from the ODMDS were negatively affecting invertebrate and/or finfish communities at hard bottom reef areas around the disposal area, six study sites were established: three close to and downdrift of the ODMDS and three upcurrent and farther from the ODMDS. These sites were monitored biannually from 2000 to 2005 using diver surveys and annually using simultaneous underwater video tows and detailed sidescan-sonar. In general, the sediment characteristics of downdrift sites and reference sites changed similarly over time. Overall, the hard bottom reef areas and their associated communities showed little evidence of degradation resulting from the movement of sediments from the Charleston ODMDS during the study period.

Shortly after the discovery of chemosynthetic ecosystems at deep-sea hydrothermal vents, similar ecosystems were found at cold seeps in the Gulf of Mexico. Over the past two decades, these sites have become model systems for understanding the physiology of the symbiont-containing megafauna and the ecology of seep communities worldwide. Symbiont-containing bivalves and siboglinid polychaetes dominate the communities, including five bathymodiolin mussel species and six vestimentiferan (siboglinid polychaete) species in the Gulf of Mexico. The mussels include the first described examples of methanotrophic symbiosis and dual methanotrophic/thiotrophic symbiosis. Studies with the vestimentiferans have demonstrated their potential for extreme longevity and their ability to use posterior structures for subsurface exchange of dissolved metabolites. Ecological investigations have demonstrated that the vestimentiferans function as ecosystem engineers and identified a community succession sequence from a specialized high-biomass endemic community to a low-biomass community of background fauna over the life of a hydrocarbon seep site.

In 2000, Florida's fast-growing hard clam aquaculture industry became eligible for federal agricultural crop insurance through the US Department of Agriculture, but the responsibility for identifying the cause of mortality remained with the grower. Here we describe the continuous water quality monitoring system used to monitor hard clam aquaculture areas in Florida and show examples of the data collected with the system. Systems recording temperature, salinity, dissolved oxygen, water depth, turbidity and chlorophyll at 30 min intervals were installed at 10 aquaculture lease areas along Florida's Gulf and Atlantic coasts. Six of these systems sent data in real-time to a public website, and all 10 systems provided data for web-accessible archives. The systems documented environmental conditions that could negatively impact clam survival and productivity and identified biologically relevant water quality differences among clam aquaculture areas. Both the real-time and archived data were used widely by clam growers and nursery managers to make management decisions and in filing crop loss insurance claims. While the systems were labor and time intensive, we recommend adjustments that could reduce costs and staff time requirements.

Electron-dense organelles (EDOs) are a characteristic feature of marine annelids adapted to hydrogen sulfide, but little is known about their origin or fate or the mechanism by which they are formed. In this study, transmission electron microscopy was used to determine the appearance, quantity, and size distribution of EDOs in body wall epithelium of the sulfide-tolerant annelid Branchioasychis americana. EDOs were enclosed by either one or two lipid bilayers with a typical diameter in the range of 0.4–1.2 μm. The contents included amorphous electron-dense material, lamellated membranes, and distinct membrane-bounded structures. In animals fixed immediately after collection from the mudflat, the EDO quantity was 0.148 μm−2. This decreased by one-third to 0.100 μm−2 after 2 weeks under sulfide-free conditions. Subsequent exposure to 250–400 μmol L−1 sulfide for ≤24 h increased the EDO quantity by 2.4-fold to 0.240 μm−2, which reverted to control levels after 24 h under sulfide-free conditions. The results show that EDOs are transient structures that are rapidly induced by sulfide, which is consistent with the hypothesis that sulfide-induced EDOs represent the upregulated autophagic degradation of mitochondria or other cellular constituents damaged by sulfide exposure.

The hydrothermal vent tubeworm Ridgeia piscesae visually dominates the vent envi- ronments in the northeast Pacific. One common vent habitat where R. piscesae flourishes is among diffuse vent flow on basaltic substrata. We used chemical analysis of discrete water samples combined with long-term temperature monitoring in 7 aggregations to characterize the immediate habitat of the 'long-skinny' morphotype of R. piscesae. We also monitored in situ growth of 536 indi- viduals from 8 separate aggregations. The temperature data show that exposure of most individuals to vent fluid at the plume level is extremely low compared to other previously studied hydrothermal vent tubeworms, which indicates significant microhabitat heterogeneity at small spatial and tempo- ral scales. The growth rates of this morphotype of R. piscesae ranged from 0 to 252 mm yr -1 and were highly variable between individuals in the same aggregation and between different vent sites. How- ever, individual growth rates in consecutive years show no significant difference and are correlated, indicating long-term stability of the sulfide source in some of these aggregations. This study found no significant relationship between initial tubeworm size and corresponding growth rates. The median plume-level temperature in an aggregation was not significantly correlated with growth rate over the entire dataset. In addition, very conservative longevity estimates suggest that this morphotype of R. piscesae lives for decades in the hydrothermal vent environments of the Juan de Fuca Ridge.

Seepiophila jonesi is a vestimentiferan tubeworm (Siboglinidae: Polychaeta) inhabiting the cold seeps of the upper slope of the Gulf of Mexico. It commonly co-occurs with Lamellibrachia luymesi, which is among the most long-lived non-clonal animals known. The growth pattern of S. jonesi is best described by a model including a size-specific probability of growth and an average growth rate that does not vary with individual size. This model, based on growth data from in situ staining and collection approximately 1 year later, predicts that S. jonesi is very slow growing and may attain ages comparable with L. luymesi. The efficacy of this model in describing L. luymesi growth rate was assessed, but the previously employed model of declining growth rate with individual size provided the better fit to the empirical data. Comparisons of both S. jonesi and L. luymesi growth rates among sites and among aggregations within a site indicate that there is some degree of habitat variability contributing to differences in growth rates. However, position of the anterior end of the worm within an aggregation did not have a significant effect on growth rate in comparisons among groups of L. luymesi from different distances from the center of an aggregation. The evolution of longevity in these species of vestimentiferans was favored by the relative stability of the seep habitat and sulfide sources, in contrast to the hydrothermal vent environment inhabited by relatively short-lived and fast-growing vestimentiferan species.

To investigate food web structure in diffuse flow vent environments, an entire macro- faunal community associated with a single aggregation of the tubeworm Ridgeia piscesae was col- lected from a vent field on the Juan de Fuca Ridge in the NE Pacific. All members of the community were identified and enumerated, and the biomass and stable carbon (δ 13 C) and nitrogen (δ 15 N) iso- tope ratios were determined for almost all taxa. Symbiont-bearing invertebrates (primarily R. pisce- sae) accounted for a vast majority of the biomass of the community, and 3 presumably grazing bac- terivorous gastropods dominated the biomass of the consumer fauna. Biomass and abundance of individuals declined from the bacterivore to the scavenger/detritivore to the predator feeding guild. Several species (a folliculinid ciliate, Idas washingtonia, Provanna variabilis) possessed unique stable isotope signatures, suggesting the possibility of symbiotic relationships with autotrophic bacteria. Stable isotope values varied widely between and occasionally within species in the lowest consumer levels suggesting a great diversity of food source 13 C and 15 N composition. Based on the distinct iso- topic values of 3 bacterivores, 3 potential pools of isotopically-distinct microbial production were identified. The 4 highest-biomass predatory species (all polynoids) possessed δ 13 C and δ 15 N values consistent with a diet that included the tubeworm R. piscesae, a species comprising 83% of the total biomass in the collection, and the gastropod Depressigyra globulus, a species comprising 10% of the total biomass in the collection. A potential specialist predator (Clypeosectus curvus) on folliculinid cil- iates was also identified. Overall the study suggested a dominant pattern of energy transfer from microbial producers to symbiont-bearing siboglinid tubeworms, various bacterivores (gastropods, polychaetes and pycnogonids), and detritivorous polychaetes to predaceous polynoids.

Previous studies have shown clear, predictable successional trends in habitat characteristics and community structure in tubeworm aggregations at 3 similar hydrocarbon-seep sites on the central upper Louisiana slope of the Gulf of Mexico. In this study, we examine these trends in quantitative community collections from 7 additional hydrocarbon-seep sites widely distributed in the northern Gulf of Mexico. The relative proportions and sizes of Lamellibrachia luymesi and Seepiophila jonesi in tubeworm aggregations were similar at new and central sites, though S. jonesi dominated some collections from new sites, a situation not previously observed at central sites. In general, sulfide declined with increasing aggregation age (average size of tubeworms), but there was more variability in this trend at the new sites. Tubeworm-associated community composition was similar at new and central sites, with only a few rare species collected at the new sites for the first time. The most significant differences in the communities at new sites were the lower relative abundance of various gastropod species, and the absence of gastropods from collections made at the Viosca Knoll site. This community type was largely restricted to young aggregations at new sites that were more isolated from other tubeworm aggregations and consisted of higher proportions of S. jonesi. As succession proceeds from young to old aggregations, many of the previously described processes were apparent at the new sites including a reduction in biomass and a shift in trophic structure from endemic primary consumers to non-endemic higher order predators. Regardless of community composition in young aggregations, succession converges on similar late-stage community types.

The Suwannee River watershed is one of the least developed in the eastern United States, but with increasing urbanization it is facing potential long-term alterations in freshwater flow to its estuary in the Gulf of Mexico. The purpose of this study was to develop biological indicators of oyster reef state along a natural salinity gradient in the Suwannee River estuary in order to allow the rapid assessment of the effect of changing freshwater input to this system. Percent cover and density of three size classes of living oysters, as well as the abundance of several predominant reef-associated invertebrates, were measured along a broad salinity gradient in the estuary and were correlated with salinity estimates from a long-term database for the preceding 12–24 mo. All eastern oyster,Crassostrea virginica, parameters (percent cover and density of three size classes) were significantly and negatively related to salinity. Data from samples collected near the lower intertidal were more closely dependent upon salinity than were samples from the higher intertidal at the same sites. Salinity differences were most closely reflected in differences in total oyster cover. This relationship corresponded with a general decline in oyster habitat with increasing distance from the mouth of the Suwannee River. Species richness was significantly and positively correlated with allC. virginica parameters (percent cover and density of three size classes), but the relationship explained only about half the variability. Density data of the hooked mussel,Ischadium recurvum, and a mud crab,Eurypanopeus depressus, were positively and strongly correlated withC. virginica parameters, likely reflecting the abundance of habitat provided byC. virginica shells. All of the biological indicators measured responded similarly along the salinity gradient, indicating they provide reliable indices of the effect of changing salinities in the Suwannee River estuary over the previous 1 or 2 yr. Some areas of positive relief defined as reefs 30 years ago are no longer oyster habitat, suggesting an ongoing decline, but nearshoreC. virginica were abundant. *** DIRECT SUPPORT *** A02BY003 00002

The growth and physiological condition of the methanotrophic hydrocarbon seep mussel Bathymodiolus childressi reflects the habitat quality of the sites it occupies on the seafloor of the upper Louisiana slope of the Gulf of Mexico. Here, tissue stable isotope compositions, growth, and physiological health of B. childressi mussels transplanted between different seep sites changed within a year to reflect conditions at the new environment. Tissue stable carbon and nitrogen isotope turnovers, although substantial, were not complete at the end of the 1-yr transplant period; they were strongly correlated with each other, and the extent of turnover of both varied by site and was related to the growth of the mussels. Carbon and nitrogen isotopic turnovers caused by metabolic tissue turnover were about 35% per year. This slow isotopic turnover in B. childressi is presumably due to its relatively slow growth and low metabolic rate. On the other hand, tissue stable sulfur isotope turnover was not correlated with either stable carbon or nitrogen isotope turnover or growth and was higher in the site with higher levels of sulfide in the environment. This indicated that tissue stable sulfur isotope turnover in these mussels is influenced by sulfide detoxification activities.

The ability of an organism to respond to changes in its environment depends upon its short-term physiological plasticity and the constraints of its genetic makeup. At hydrothermal vents and cold seeps, the spatially variable physiological characteristics of symbiont-bearing animals are often assumed to reflect short-term physiological adjustments to a patchy and dynamic chemical environment. However, the extent to which these spatially variable responses represent fixed characteristics unique to animals inhabiting the different environments (such as might arise from genetic differentiation) has not been tested. The seep mussel Bathymodiolus childressi depends upon methanotrophic bacteria for the bulk of its nutrition and inhabits a range of environments where it displays varying growth and body condition. In this study, we first investigated the multiscale environmental and physiological variability of B. childressi by measuring dissolved gas concentrations and mussel body condition in 12 mussel beds at four geographically distinct sites. Brine-dominated seeps tended to have higher methane and sulfide concentrations and host mussels of better body condition than petroleum-dominated sites. Then, using two transplant experiments, we evaluated whether local environmental conditions or stock effects determined the observed differences in growth and body condition of B. childressi. In all cases, mussels transplanted to new sites acquired or nearly acquired the characteristics of their host population, illustrating the primary role of the environment in determining the physiological characteristics of resident mussels. However, mussels from different sites sometimes responded differently to the same environment, suggesting stock-related effects also play a role in the spatial variation observed in the physiology of chemosynthetic fauna.

The slow rate of change in hydrocarbon seep communities on the upper ­Louisiana slope prevents the use of direct observation in studying successional trends. We used a chronosequence consisting of three presumed stages – juvenile, adult and senescent – to test a previous model which proposed that sulfide availability and vestimentiferan growth and physiological health decline over the lifespan of a vestimenti­feran aggregation. We replicated the chronosequence at two sites to simultaneously ­explore the influence of spatial heterogeneity on the characteristics of these communities. We determined environmental sulfide concentrations and vestimentiferan growth and condition in at least two vestimentiferan aggregations representative of each stage at each of these two sites. Hydrogen sulfide concentrations were highly variable both above and below the sediment's surface, and sulfide was present in high concentrations to sediment depths of 70 cm. Vestimentiferan growth and condition varied significantly on multiple spatial scales from sites separated by tens of kilometers, to aggregations separated by tens to hundreds of meters within a site, to individual vestimentiferans ­separated by tens of centimeters within an aggregation. The striking variability in both environmental sulfide and vestimentiferan growth and condition within individual ­aggregations suggests a crucial role for microhabitat variability in the persistence of vestimentiferan aggregations at these sites. Few significant successional trends in ­environmental sulfide or vestimentiferan growth and condition were found over the three stages tested.

Biologically generated structures create habitat and influence the distribution and abundance of species in many marine systems. In the rather monotonous and nutrient-poor environment of the deep-sea, cold seep environments and their associated chemosynthetic communities offer islands of primary production and habitat to a generally sparsely distributed macrofauna. In this study, we investigate the structure of macrofaunal assemblages associated with vestimentiferan aggregations on the upper Louisiana slope of the Gulf of Mexico and the relationships between assemblage composition and the size and complexity of the vestimentiferan-generated habitat. Using custom-designed and custom-built devices, we collected seven whole vestimentiferan aggregations along with their associated fauna during the summers of 1997 and 1998. Sixty-five species were found associated with the four vestimentiferan aggregations collected in 1998, more than doubling the number of species previously reported for seeps in this region. Individual aggregations contained between 23 and 44 different non-vestimentiferan species. General trends of increasing species richness with increasing habitat size and increasing faunal density with increasing habitat complexity were identified, but substantial variability suggested other factors also control the composition of faunal associates. Faunal abundances decreased with increasing aggregation age. Seep endemics dominated the communities of younger aggregations, but non-endemic species dominated communities of older aggregations. Relative dominance of the heterotrophic community by primary consumers decreased, while predatory secondary and higher-order consumers increased with increasing aggregation age. These trends are discussed in terms of successional changes in aggregation structure, habitat heterogeneity and environmental conditions.

Lamellibrachia luymesi is a long-lived vestimentiferan polychaete that produces biogenic habitat at hydrocarbon seeps on the upper Louisiana slope of the Gulf of Mexico. Lamellibrachia luymesi relies on endosymbiotic, chemoautotrophic bacteria for nutrition which are supplied with hydrogen sulphide acquired from seep sediments by the tube worms. In this study, an individual-based model is developed for L. luymesi aggregations. The results show that aggregations can persist for centuries because of extremely low mortality rates. Recruitment patterns reflect intraspecific competition for settlement space, with the recruitment period estimated between 11 and 68 years. Substantial hydrogen sulphide requirements are estimated for large aggregations of L. luymesi, exceeding 30 mmol h−1. In addition to modifying habitat through physical structure, L. luymesi may be considered to be an ecosystem engineer because of its profound effect on the chemical environment at hydrocarbon seep sites.

Land cover patterns were evaluated in 29 estuarine watersheds of South Carolina to determine relationships between urban/suburban development and estuarine habitat quality. Principal components analysis and Pearson product moment correlation analyses were used to examine the relationships between ten land cover categories and selected measures of nutrient or bacterial enrichment in the water column and contaminant enrichment in sediments. These analyses indicated strong relationships between land cover categories representing upland development and a composite measure of 24 inorganic and organic contaminants using the Effect Range Median-Quotient (ERM-Q). Similar relationships also were observed for the summed concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, and metals. Data obtained from tidal creeks generally showed stronger correlations between urban/suburban land use and pesticides and metals compared to data obtained from larger open water habitats. Correlations between PAH concentrations and the urban/suburban land cover categories were similar between creek and open water habitats. PCB concentrations generally showed very little relationship to any of the land cover categories. Measures of nutrient enrichment, which included total Kjeldahl nitrogen (TKN), nitrate-nitrite, phosphorus, chlorophyll-a, and total organic carbon, were generally not significantly correlated with any land cover categories, whereas fecal coliform bacteria were significantly and positively correlated with the urban/suburban land cover categories and negatively correlated with the non-urban land cover categories. Fecal coliform correlations were stronger using data from the open water sites than from the tidal creek sites. Both ERM-Q and fecal coliform concentrations were much greater and more pervasive in watersheds with relatively high (50%) urban/suburban cover compared to watersheds with low (30%) urban/suburban cover. These analyses support the hypotheses that estuarine habitat quality reflects upland development patterns at large spatial scales, and that upland urbanization can result in increased risk of biological degradation and reduced safe human use of South Carolina's coastal resources.

In the basalt-hosted hydrothermal vent habitat around 9°50 N on the East Pacific Rise, the vestimentiferan tubeworms Tevnia jerichonana and Riftia pachyptila (Polychaeta: Siboglinidae) commonly settle before the mussel Bathymodiolus thermophilus (Bivalvia: Mytilidae). We removed six aggregations of R. pachyptila and deployed mussels on the cleared sources of diffuse flow to test the effect of the B. thermophilus on the subsequent colonization by the tubeworms. None of the transplanted mussels persisted on the cleared sources of diffuse flow; however, aggregations of R. pachyptila grew in half of the clearances. We collected one of the aggregations of R. pachyptila along with the associated fauna for determination of relative abundance and biomass in this one-year-old community. This aggregation consisted of 647 specimens of R. pachyptila that hosted individuals of 24 species, including small individuals of T. jerichonana and B. thermophilus. The abundance of the associated fauna was numerically dominated by gastropods, and the biomass was dominated by the Alvinellid polychaete Paralvinella grasslei. Following an eruption, the vestimentiferan tubeworms Tevnia jerichonana and Riftia pachyptila (Polychaeta: Siboglinidae) quickly colonize the basalt-hosted hydrothermal vents around 9°50 N (East Pacific Rise) and soon grow to visually dominate these habitats (1, 2, 3). Colonization by the vent mussel Bathymodiolus thermophilus often follows shortly, and the mussels eventually overgrow the tubeworms at most sites (2, 4, 5). Both tubeworms and mussels harbor sulfur-oxidizing chemoautotrophic endosymbionts, which provide the bulk of their nutrition (6, 7). However, mussels have also maintained the ability to filter-feed (8), which apparently allows them to occupy a wider range of environmental conditions and better tolerate declining hydrothermal vent activity than the tubeworms (9). The mechanism of ecological succession in these hydrothermal vent habitats is not fully understood, but may be regulated by a combination of pre-settlement factors, such as the use of biogenic cues (3) and the response to geochemical changes (2), and post-settlement factors, such as physical overgrowth (4) and resource competition (5). We conducted a manipulative experiment to test the hypothesis that the mussel B. thermophilus prevents further colonization of a vent by tubeworms. In May 1998, six aggregations of the giant tubeworm R. pachyptila were cleared from a site named Riftia Field (9°50.705 N 104°17.593 W). The original location and source of diffuse flow for each aggregation were marked and recorded on video. After the aggregations were cleared, the temperatures of the venting fluid were measured, using the low-temperature probe of the DSV Alvin, and ranged from 20–22 °C above ambient at the six locations. Then about 600 mussels were collected from a nearby site (“East Wall”, 9°50.614 N 104° 17.509 W) and about 200 were deployed over each of three cleared sources of diffuse flow (treatments). Mussels were not deployed on the three other cleared areas (conReceived 28 April 2004; accepted 4 October 2004. * To whom correspondence should be addressed. E-mail: breea@psu.edu † Present address: Department of Fisheries and Aquatic Sciences, University of Florida, Gainesville, FL 32653. Reference: Biol. Bull. 207: 177–182. (December 2004) © 2004 Marine Biological Laboratory

Vestimentiferan tubeworms, symbiotic with sulfur-oxidizing chemoautotrophic bacteria, dominate many cold-seep sites in the Gulf of Mexico. The most abundant vestimentiferan species at these sites, Lamellibrachia cf. luymesi , grows quite slowly to lengths exceeding 2 meters and lives in excess of 170–250 years. L. cf. luymesi can grow a posterior extension of its tube and tissue, termed a “root,” down into sulfidic sediments below its point of original attachment. This extension can be longer than the anterior portion of the animal. Here we show, using methods optimized for detection of hydrogen sulfide down to 0.1 μM in seawater, that hydrogen sulfide was never detected around the plumes of large cold-seep vestimentiferans and rarely detectable only around the bases of mature aggregations. Respiration experiments, which exposed the root portions of L. cf. luymesi to sulfide concentrations between 51–561 μM, demonstrate that L. cf. luymesi use their roots as a respiratory surface to acquire sulfide at an average rate of 4.1 μmol⋅g −1 ⋅h −1 . Net dissolved inorganic carbon uptake across the plume of the tubeworms was shown to occur in response to exposure of the posterior (root) portion of the worms to sulfide, demonstrating that sulfide acquisition by roots of the seep vestimentiferan L. cf. luymesi can be sufficient to fuel net autotrophic total dissolved inorganic carbon uptake.