Jellyfish (cnidarian subphylum Medusozoa and phylum Ctenophora) exist since the Cambrian period. Since then, these members of gelatinous zooplankton have developed various life forms and lifestyles, which enables them to dwell in nearly all habitats of the global ocean. Recent reports on the local and regional increase of jellyfish blooms, triggered debate over the actual cause and consequences of observed fluctuations and dragged the attention of broader scientific community, resulting in mount of evidence on the role, importance and impacts of jellyfish in global ocean ecosystem. At the same time, studies exposed numerous knowledge gaps, which we need to address to accurately integrate jellyfish and jellyfish-derived organic matter into marine food webs, biogeochemical budgets and models. We propose a very broad jellyfish session that brings together researchers from different disciplines to examine jellyfish and related topics from different perspectives filling recognized knowledge gaps. This session welcomes studies that examine jellyfish diversity, distribution, physiology, behaviour, and ecology, their interactions with other members of the marine food web, especially with microbes and jellyfish potential predators, with particular emphasis on studies that use e-DNA, omics approaches and microscale analyses. We seek applied research on advances in jellyfish observation techniques (from remote sensing to systematic transects, drone observations, underwater cameras, ROVs and Citizen Science) and efforts to establish common monitoring standards and criteria. Studies employing all types of modelling, including fluid dynamics, ecosystem models, individual-based models, Lagrangian models, probabilistic models, coupled physical-biogeochemical models, providing insights into jellyfish dynamics and dispersion on local, regional and global scales, are welcomed. Research investigating the causes and consequences of jellyfish blooms for ecosystem functioning, food web structure, biogeochemical state of marine ecosystems, and the role of jellyfish in marine ecosystem services are seeked. We are interested in studies understanding jellyfish in the past (including fossils) and in the context of future changes in oceanic habitats related to increases in seawater temperature, changes in salinity, nutrient regimes, ocean dynamics, ocean sprawl (offshore platforms, aquaculture facilities, wind farms), and the introduction of non-indigenous species. Last, but not least, we want to welcome research tackling jellyfish and human interaction, from the valorisation of jellyfish, as food or fertilisers and in cosmetics and pharmacology as potential producers of bioactive molecules, to the effects of jellyfish on human health and well-being and jellyfish in history, art, and popular culture.
Lead Organizer: Tinkara Tinta, National Institute of Biology (email@example.com)
Martin Vodopivec, National Institute of Biology (Martin.Vodopivec@nib.si)
Laura Prieto, Instituto de Ciencias Marinas de Andalucia (firstname.lastname@example.org)
Mohamed Najib Daly Yahia, Qatar University (email@example.com)
Enhanced Swimming and Physiological Limits of Robotically Controlled Aurelia aurita Jellyfish (5983)
Primary Presenter: Simon Anuszczyk, California Institute of Technology (firstname.lastname@example.org)
Jellyfish have the lowest cost of transport of all metazoans and live in a wide range of ocean temperature, salinity, pH, and depth, due to their evolutionary success and adaptability. We study the performance envelope of Aurelia aurita jellyfish with embedded microelectronic swim controllers that manipulate the frequency of body contractions during swimming. Previous work has demonstrated enhanced jellyfish vertical swimming speeds of 2.8 times baseline speeds without swim controllers. Indirect measurements suggest that this enhanced swimming can be achieved without proportional increases in energy consumption. Manipulating the frequency of body contractions allows us to approach the animal’s biological velocity limits and better understand the role of swimming mechanics in the observed evolutionary success. We characterize the animal’s physiological limits to study the untapped potential for faster and more efficient swimming. These limits may be different from commonly observed swimming speeds due to impacts of feeding or other environmental variables. We then investigate stimulated animal swimming efficiency metrics. This will help to determine if these enhanced swimming speeds are energetically feasible for deploying stimulated jellyfish with attached sensors for ocean monitoring.
Characterizing Pathways of the Biological Carbon Pump in two Fjords with Contrasting Pelagic Food Web Structures (6583)
Primary Presenter: Kea Witting, GEOMAR Helmholtz Centre for Ocean Research Kiel (email@example.com)
Due to rising atmospheric carbon dioxide, alterations in pathways of the biological carbon pump (BCP) mediated by pelagic organisms as a major component of carbon export in the ocean need to be understood. This study compares the BCP of two adjacent Norwegian fjords with similar topography but different pelagic ecosystems, one more classically fish dominated and one dominated by the deep-sea medusa Periphylla periphylla. A multitude of catching devices (MultiNets) and imaging instruments (UVP5, PELAGIOS) were compared in this study. This allowed to understand differing pathways of the BCP and identify possible sampling biases or knowledge gaps resulting from instruments used. We also hypothesized that the presence of mesopelagic fish species can be detected in the seabed sediment of the fjord by using the relatively new approach of using sedimentary environmental DNA (eDNA). Results indicate major differences between the fjord ecosystems that can be seen across all the different instruments used. High appendicularian abundances in one fjord were found mainly by the data collected with the UVP5, which was validated by video material gathered with the PELAGIOS. Copepods could mainly be detected using the MultiNets and UVP5 as they were too small to identify exactly using the PELAGIOS. Additionally, this study gives a first record of P. periphylla occurring in the Masfjord, which is typically used to represent a classical fjord ecosystem structure. All findings suggest a lower carbon sequestration rate in the P. periphylla dominated Lurefjord, due to BCP pathway alterations.
GELATINOUS THREATS TO FARMED SALMON HEALTH: INSIGHTS FROM MORPHOLOGICAL AND METABARCODING APPROACHES (6859)
Primary Presenter: María Algueró-Muñiz, University of Glasgow (firstname.lastname@example.org)
Salmon aquaculture loses c.20% of annual production as a result of gill disease, which threatens the sustainability of the industry. Complex gill disease (CGD) is a condition caused by a suite of different stressors and jellyfish are increasingly considered as one of the important drivers. As there are no ‘treatments’ for these CGD agents, early warning can improve prevention and thus sustainability whilst allowing losses to be mitigated. In the current study, we present a seven-month longitudinal planktonic survey of salmon aquaculture on two different sites off the west coast of Scotland (UK), covering both spring and autumn blooms when the periods of highest mortalities in the farms typically occur. Our method combines environmental DNA (eDNA) metabarcoding and morphological data to assess plankton species diversity and abundance and relate these to fish health indicators, including mortality and CGD. Our results identify multiple planktonic species as potential drivers of the events including hydromedusae and other gelatinous zooplankton. We hope that our approach is a step change in mitigating losses caused by planktonic threats, improving both the sustainability and productivity of the salmonid aquaculture industry.
DIET DIVERSITY IN STRONG VERTICAL MIGRATORS: CASE STUDY OF SALPA ASPERA IN THE MESOPELAGIC FOOD WEB OF THE NW ATLANTIC (7129)
Primary Presenter: Paola Batta Lona, University of Connecticut (email@example.com)
Gelatinous zooplankton are important grazers in mesopelagic food webs, although their diet and trophic impacts are unclear. One group, salps (Tunicata), are efficient filter feeders with extensive vertical migration behaviors that transport carbon through the mesopelagic zone. Metabarcoding allows accurate detection of a broad taxonomic range of consumed prey and is thus providing new insights into trophic pathways and dynamics of pelagic food webs. We report results on the prey diversity of Salpa aspera from a field expedition of the Ocean Twilight Zone project in the NW Atlantic Ocean. Diet composition was determined with DNA metabarcoding analysis of the gut contents of Salpa aspera. Salps (solitary and aggregate forms) for this study were collected in vertically-stratified tows (0 – 200, 200 – 400, 400 – 600, 600 – 1000 m) of a 10-m2 MOCNESS in the NW Atlantic Slope Water during March 2020. DNA was extracted from salp gut contents and sequenced for V4 and V9 hypervariable regions of the 18S rRNA gene. Taxonomic assignments of V4 and V9 sequences were resolved and classified using custom scripts and reference databases. Multivariate statistical analysis was used to compare prey composition for salps collected from 4 depth strata at 5 stations. When combined with diel vertical distribution patterns from in situ shadowgraph imaging, results of the metabarcoding analysis of the salp diet were used to summarize the trophic relationships of S. aspera, infer sources of productivity, evaluate the impacts of salp forms (aggregate or solitary) and vertical migration on particle and energy transfer in the mesopelagic ecosystem.
Using in situ imaging to describe the gelatinous zooplankton communities of the Gulf of Alaska (7223)
Primary Presenter: Hannah Kepner, University of Alaska Fairbanks (firstname.lastname@example.org)
The Northern Gulf of Alaska (NGA) marine environment is highly variable, both in space and time, presenting technical challenges for describing its zooplankton communities. Abundances and distributions can be poorly resolved by plankton net sampling due to patchiness, a problem that is further compounded by the damage inflicted on fragile soft-bodied organisms during collection. High resolution data is limited by practical constraints on both sample collection and taxonomic analysis. To resolve these challenges, we have deployed an In Situ Ichthyoplankton Imaging System Deep-Focus Particle Imager (ISIIS-DPI) to describe zooplankton community structure in the NGA. The ISIIS-DPI is an undulating towed vehicle with a wide array of mounted instrumentation, and an imaging system of 3 line-scan cameras that images ~250 liters/second while conserving the scale of particles and plankton. Deployments are illuminating the substantial variability occurring within most components of the epipelagic zooplankton community. In particular, here we will describe the fine-scale vertical and horizontal aggregative patterns of gelatinous zooplankton abundance and distribution in the NGA, and relate them to biophysical drivers. For example, we show that abundances are elevated around frontal features, as well as concentrated near the pycnocline. Furthermore, we will demonstrate the prominence of the most fragile members of the gelatinous zooplankton - ctenophores - within the NGA that are virtually missed by traditional sampling methods.
DEEP SEA MINING AND JELLYFISH: PRELIMINARY RESULTS OF BASELINE ROV SURVEYS ON THE GELATINOUS ZOOPLANKTON COMMUNITY OF THE EASTERN CLARION-CLIPPERTON ZONE (7508)
Primary Presenter: Dhugal Lindsay, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) (email@example.com)
Here we report on the preliminary results from Environmental Impact Assessment Campaigns 5b and 5e of the vessel Maersk Launcher, contracted by The Metals Company (formerly Deep Green), from 28 February to 22 April (5b) and 11 November to 19 December (5e) 2021. Data on the gelatinous zooplankton community was collected using ROV Odysseus (Pelagic Research Services) from the eastern Clarion-Clipperton Zone (CCZ), within the NORI-D license block (State sponsor: The Republic of Nauru). Horizontal transects at various depth horizons, including the proposed depth for release of a midwater sediment plume, were conducted during both day and night. The ROV video was analyzed using the Squidle-based annotation system co-developed by JAMSTEC/GreyBits Engineering, and Exemplar images for training of both humans and machines were captured with environmental metadata into a relational database to also be used for developing a machine-learning-assisted analysis pipeline to use in future studies. Voucher specimens collected by the ROV were sequenced to investigate connectivity between midwater ecoregions. Preliminary results characterizing the abundant and diverse midwater gelatinous zooplankton assemblage will be introduced.
SS056B Jellyfish in the Changing Ocean
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Time: 5:00 PM
Room: Sala Santa Catalina