Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

These data are being published in Dykman et al. (2023).

Animals were collected from deep-sea hydrothermal vent sites at the East Pacific Rise 9°50’N vent field (EPR 9N) during two cruises, one in December of 2019 (AT42-21) using DSV Alvin and one in March of 2021 (RR2102) using ROV Jason. Hosts were sampled from a range of thermal zones and substrate types, including basalt and active sulfide chimneys. This sampling design ensured our study covered a broad representative diversity of potential hosts in the active vent field and increased the chance of encountering parasite species that are patchily distributed in host populations. For the vent fishes, we include dissection data from preserved specimens collected during two prior cruises: two whole frozen Thermarces cerberus collected in April, 2017 (AT37-12); and preserved gut contents of 22 Thermichthys hollisi collected in February, 2007 (AT15-15) (Buckman 2009).

Large tubeworms and mussels were collected into sealed, insulated “bioboxes” using the manipulator of the HOV or ROV. Mobile hosts such as fish, crabs, and squat lobsters were collected using suction samplers or box-style crayfish traps baited with tubeworm and mussel tissue and left overnight on the seafloor. Small fauna, including crustaceans, mollusks, and polychaetes were gathered opportunistically from geological samples or directly targeted with suction sampling or faunal grabs.

Potential hosts were dissected fresh aboard the ship or frozen at -80°C immediately upon arrival at the surface. Each potential host was thoroughly examined following standard methods for detecting metazoan parasites (Kuris et al. 2008, Morton et al. 2021, McLaughlin 2018).

Before dissection, hosts were identified to species using reference guides (Desbruyères et al. 2006). When species ID was uncertain, hosts were given a morphogroup ID or grouped at a higher taxonomic level (i.e., Family or Genus). In some cases, host identification was based on COI barcoding using universal metazoan primers (Folmer et al. 1994).

Host length was measured along the maximum dimension using standard protocol for each taxon: gastropods were measured from the base of the column to the apex; crabs were measured at the maximum carapace width; and shrimp were measured by carapace length along the midline, including the rostrum. Standard length and total length were recorded for fish. Additional host information, such as weight, sex, gut contents, and condition, were recorded when possible.

The exterior of each specimen and the wash from its storage bag or compartment were carefully inspected for ectoparasites. Internal parasites were detected visually by pressing host tissues between two glass plates, shining transmitted light from beneath and carefully scanning the entire slide in a grid pattern under a dissecting scope at 10-50x magnification. For large animals, each organ was examined individually to record the site of infection. Small animals were squashed and examined whole.

All symbionts detected by our methods (including metazoan parasites, commensals, protozoan parasites, and microbial pathologies) were assigned a species or morphogroup name and counted. When a species or morphogroup was first encountered or found in a new host species, several individuals were measured, photographed, and preserved for further morphological and molecular description.

Photos were taken using an eyepiece camera or a camera attached to a microscope photo tube and C-mount. Parasites were measured with a micrometer installed in the microscope eyepiece. Parasite specimens were preserved in 80% ethanol for morphological description and 95% ethanol for genetic analysis. Specialist taxonomists were consulted to ensure morphogroups were distinct to the species level. Parasite morphogroups were classified to the lowest possible taxonomic level based on morphological description and/or 18S and 28S barcoding (Bray et al. 2014). Barcoding was used as the primary method for classification of juvenile and cyst stages.

This dataset includes true parasites (macroparasites, castrators, and trophically-transmitted parasites) as well as other symbionts such as commensals and egg predators.

BCO-DMO Processing Notes:
* Added data file in Data File section to comply with data base requirements
* Dataset version 1 primary data file (version data 2022-08-24) replaced with version 2 (2023-05-11). The change is due to "Two parasite morphospecies names were updated based on new genetic information."
* File "PARASITES_VENT_DISSECTION.xlsx" (submitted to bcodmo on 2023-05-10) loaded as a data table into the BCO-DMO data system.  Values "NO" "NR" and "NA" were identified as missing data values but preserved as strings within the data table instead of becoming blank (null) values to indicate no data. No modifications were made to the column names or values.

NSF Award Abstract:
Hydrothermal vents support oases of life in the deep sea and are inhabited by unusual organisms that use chemical energy instead of photosynthesis as the basis of their food web. However, because the vents occur in geologically active areas of the seafloor, entire communities can be eradicated by catastrophic natural disturbances such as eruptions. The main objectives of this project are to quantify how quickly these communities recover from catastrophic disturbance and to determine what processes influence their resilience. The project focuses on both the structure (species diversity) and function (trait diversity) of the communities. The investigators will examine vents on an active segment of the East Pacific Rise where eruptive disturbance occurs on decadal time scales. These activities will create an unprecedented long-term (>14-year) quantitative time-series of colonist species composition and function. The application of trait-based analysis to the question of biological succession at vents has the potential to change the way we think about resilience in other patchy, transient and regionally-connected ecosystems. By considering how traits change over time, the researchers can untangle which species-level characteristics most influence abundance and distribution. The project objectives have broad significance with the growing potential for human-caused disturbances at deep-sea vents through deep-sea mining. Additional impacts include strengthening participation of under-represented minorities in marine science and contributing to international database development for functional traits of deep-sea vent species.

The unique, chemosynthesis-fueled fauna inhabiting deep-sea hydrothermal vents are subject to tectonic and eruptive disturbance that can eradicate entire communities. The main objectives of this project are to quantify how quickly these communities recover from catastrophic disturbance and to determine what processes influence their resilience. The focus is on vents on an active segment of the East Pacific Rise where eruptive disturbance occurs on decadal time scales. Field data on colonization and larval supply are used to characterize not only species succession but also the trajectory of functional diversity after a recent (2006) eruption. A new, promising approach to the colonization studies comes from incorporating trait-based analysis of functional diversity. Functional trait analysis is increasingly recognized in terrestrial and freshwater systems as a tool to holistically answer ecological questions, but trait analysis has not been often applied to marine systems. By considering how traits of incoming colonists change over time, the investigators can untangle which species-level factors most influence abundance and distribution. This project will create an unprecedented long-term (>14-year) quantitative time-series of colonist species composition and function. It includes multiple vent sites to encompass the full diversity of habitat conditions, and assesses both local processes and regional connectivity through larval supply. Field observations at individual sites contribute to broader questions when placed in the context of metacommunity theory. In this theoretical framework, field data such as this can be used to answer such questions as how the eradication of the vent community at a particular site affects the persistence of the metacommunity overall, and which vent sites contribute most to regional biodiversity.

NSF Award Abstract:
Over four decades of research have shown that tiny free-swimming offspring of the unique inhabitants of hydrothermal vents can disperse effectively between their specialized habitats. Yet, we know almost nothing about how these larval animals complete the journey by locating and settling down in suitable locations. This question remains one of the key unresolved puzzles in the ecology of the deep sea and is becoming increasingly important to solve as hydrothermal vents are becoming threatened by human impacts. The investigators suggest that the films of bacteria that first form at vents are good signposts for settlement of larvae because they indicate that the hydrothermal vents are suitable for life. This project uses a combined program of field experiments, cutting-edge molecular biology techniques, and shipboard experiments with hydrothermal-vent larvae and cultured bacterial films. The project also connects undergraduate research interns at a primarily undergraduate institution (Western Washington University) with undergraduate research interns at two research institutions (Rutgers and Woods Hole Oceanographic Institution) while working on the project at sea together. Finally, the team is producing a science-in-action documentary filled with ocean science and exploration intended for television distribution and museum screenings. The investigators are using footage of the deep-sea vents, shipboard and diving operations, and laboratory work to create a documentary that highlights the foundation of scientific research—hypothesis-driven research, the application of the scientific method, and the importance of critical thinking—all in the framework of the study of an exciting, but threatened, ecosystem.

Hydrothermal vents are particularly tractable systems in which to study questions about the roles of biofilms in larval settlement because biofilms at vents are relatively low-complexity; vent animals are strictly dependent on vent microbes, often through symbiotic partnerships acquired after settlement; and environmental variations are present within the range of a common larval pool. Moreover, decades of research on settlement in model organisms give us good insight into biofilm cues; there is solid foundational understanding about colonization patterns at vents; we now have excellent tools to collect, identify, and culture vent larvae and microbes; and modern environmental "-omics" techniques are a good tool to characterize biological cues produced by biofilms. The project provides an unprecedented, quantitative look into the role of microbial biofilms in structuring larval settlement at hydrothermal vents, achieved only through the close collaboration of microbial and larval ecologists. The combined field program of short-term settlement experiments, microbial "-omics" work, and subsequent shipboard settlement experiments allows the investigative team to use field experiments to statistically model the factors that best predict larval settlement in the field, then test those predictions with shipboard experiments that decouple covarying conditions. This extensive characterization of putative larval settlement cues and their relationship to colonization success in heterogeneous vent habitat niches will contribute to a broader understanding of colonization success across diverse marine ecosystems. Understanding the role that the initial settlement of larvae plays in the recovery and resilience of hydrothermal-vent ecosystems is critical to developing informed management plans for deep-sea mining.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.