Sutherland
Kelly R.
Sutherland
Kelly R.
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ArticlePropulsive design principles in a multi-jet siphonophore.(Company of Biologists, 2019-02-27) Sutherland, Kelly R. ; Gemmell, Brad J. ; Colin, Sean P. ; Costello, John H.Coordination of multiple propulsors can provide performance benefits in swimming organisms. Siphonophores are marine colonial organisms that orchestrate the motion of multiple swimming zooids for effective swimming. However, the kinematics at the level of individual swimming zooids (nectophores) have not been examined in detail. We used high speed, high resolution microvideography and particle image velocimetry (PIV) of the physonect siphonophore, Nanomia bijuga, to study the motion of the nectophores and the associated fluid motion during jetting and refilling. The integration of nectophore and velum kinematics allow for a high-speed (maximum ∼1 m s−1), narrow (1-2 mm) jet and rapid refill as well as a 1:1 ratio of jetting to refill time. Scaled to the 3 mm nectophore length, jet speeds reach >300 lengths s−1. Overall swimming performance is enhanced by velocity gradients produced in the nectophore during refill, which lead to a high pressure region that produces forward thrust. Generating thrust during both the jet and refill phases augments the distance travelled by 17% over theoretical animals, which generate thrust only during the jet phase. The details of velum kinematics and associated fluid mechanics elucidate how siphonophores effectively navigate three-dimensional space and could be applied to exit flow parameters in multijet underwater vehicles.
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ArticleQuestioning the rise of gelatinous zooplankton in the world's oceans(American Institute of Biological Sciences, 2012-02) Condon, Robert H. ; Graham, William M. ; Duarte, Carlos M. ; Pitt, Kylie A. ; Lucas, Cathy H. ; Haddock, Steven H. D. ; Sutherland, Kelly R. ; Robinson, Kelly L. ; Dawson, Michael N. ; Decker, Mary Beth ; Mills, Claudia E. ; Purcell, Jennifer E. ; Malej, Alenka ; Mianzan, Hermes ; Uye, Shin-Ichi ; Gelcich, Stefan ; Madin, Laurence P.During the past several decades, high numbers of gelatinous Zooplankton species have been reported in many estuarine and coastal ecosystems. Coupled with media-driven public perception, a paradigm has evolved in which the global ocean ecosystems are thought to he heading toward being dominated by “nuisance” jellyfish. We question this current paradigm by presenting a broad overview of gelatinous Zooplankton in a historical context to develop the hypothesis that population changes reflect the human-mediated alteration of global ocean ecosystems. To this end, we synthesize information related to the evolutionary context of contemporary gelatinous Zooplankton blooms, the human frame of reference for changes in gelatinous Zooplankton populations, and whether sufficient data are available to have established the paradigm. We conclude that the current paradigm in which it is believed that there has been a global increase in gelatinous Zooplankton is unsubstantiated, and we develop a strategy for addressing the critical questions about long-term, human-related changes in the sea as they relate to gelatinous Zooplankton blooms.
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ArticleManeuvering performance in the colonial siphonophore, Nanomia bijuga(MDPI, 2019-09-05) Sutherland, Kelly R. ; Gemmell, Brad J. ; Colin, Sean P. ; Costello, John H.The colonial cnidarian, Nanomia bijuga, is highly proficient at moving in three-dimensional space through forward swimming, reverse swimming and turning. We used high speed videography, particle tracking, and particle image velocimetry (PIV) with frame rates up to 6400 s−1 to study the kinematics and fluid mechanics of N. bijuga during turning and reversing. N. bijuga achieved turns with high maneuverability (mean length–specific turning radius, R/L = 0.15 ± 0.10) and agility (mean angular velocity, ω = 104 ± 41 deg. s−1). The maximum angular velocity of N. bijuga, 215 deg. s−1, exceeded that of many vertebrates with more complex body forms and neurocircuitry. Through the combination of rapid nectophore contraction and velum modulation, N. bijuga generated high speed, narrow jets (maximum = 1063 ± 176 mm s−1; 295 nectophore lengths s−1) and thrust vectoring, which enabled high speed reverse swimming (maximum = 134 ± 28 mm s−1; 37 nectophore lengths s−1) that matched previously reported forward swimming speeds. A 1:1 ratio of forward to reverse swimming speed has not been recorded in other swimming organisms. Taken together, the colonial architecture, simple neurocircuitry, and tightly controlled pulsed jets by N. bijuga allow for a diverse repertoire of movements. Considering the further advantages of scalability and redundancy in colonies, N. bijuga is a model system for informing underwater propulsion and navigation of complex environments.
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ArticleA ctenophore (comb jelly) employs vortex rebound dynamics and outperforms other gelatinous swimmers(The Royal Society, 2019-03-20) Gemmell, Brad J. ; Colin, Sean P. ; Costello, John H. ; Sutherland, Kelly R.Gelatinous zooplankton exhibit a wide range of propulsive swimming modes. One of the most energetically efficient is the rowing behaviour exhibited by many species of schyphomedusae, which employ vortex interactions to achieve this result. Ctenophores (comb jellies) typically use a slow swimming, cilia-based mode of propulsion. However, species within the genus Ocyropsis have developed an additional propulsive strategy of rowing the lobes, which are normally used for feeding, in order to rapidly escape from predators. In this study, we used high-speed digital particle image velocimetry to examine the kinematics and fluid dynamics of this rarely studied propulsive mechanism. This mechanism allows Ocyropsis to achieve size-adjusted speeds that are nearly double those of other large gelatinous swimmers. The investigation of the fluid dynamic basis of this escape mode reveals novel vortex interactions that have not previously been described for other biological propulsion systems. The arrangement of vortices during escape swimming produces a similar configuration and impact as that of the well-studied ‘vortex rebound’ phenomenon which occurs when a vortex ring approaches a solid wall. These results extend our understanding of how animals use vortex–vortex interactions and provide important insights that can inform the bioinspired engineering of propulsion systems.
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PreprintA comparison of filtration rates among pelagic tunicates using kinematic measurements( 2009-11) Sutherland, Kelly R. ; Madin, Laurence P.Salps have higher filtration rates than most other holoplankton, and are capable of packaging and exporting primary production from surface waters. A method of kinematic analysis was employed to accurately measure salp feeding rates. The data were then used to explain how diverse body morphologies and swimming motions among species and lifecycle stages influence salp feeding performance. We selected five species, representing a range of morphologies and swimming styles, and used digitized outlines from video frames to measure body-shape change during a pulse cycle. Time-varying body volume was then calculated from the digitized salp outlines to estimate the amount of fluid passing through the filtering mesh. This non-invasive method produced higher feeding rates than other methods and revealed that body volume, pulse frequency and degree of contraction are important factors for determining volume filtered. Each species possessed a unique combination of these three characteristics that resulted in comparable filtration (range: 0.44 - 15.33 ml s-1) and normalized filtration rates (range: 0.21 – 1.27 s-1) across species. The convergence of different species with diverse morphologies on similar normalized filtration suggests a tendency towards a flow optimum.
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DatasetJeDI: Jellyfish Database Initiative(Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2015-03-09) Condon, Robert H. ; Lucas, Cathy H. ; Duarte, Carlos M. ; Pitt, Kylie A. ; Haddock, Steven H. D. ; Madin, Laurence P. ; Brodeur, Richard D. ; Sutherland, Kelly R. ; Mianzan, Hermes W. ; Purcell, Jennifer E. ; Decker, Mary Beth ; Uye, Shin-Ichi ; Malej, Alenka ; Bogeberg, Molly ; Everett, John T. ; Gibbons, Mark ; Gonzalez, H. ; Hay, S. ; Hensche, N. ; Hobson, R. J. ; Kingsford, Michael J. ; Kremer, P. ; Lehtiniemi, Maiju ; Ohman, Mark ; Rissik, D. ; Sheard, K. ; Suthers, Iain ; Coleman, N. ; Costello, John H. ; Gershwin, L. A. ; Graham, William M. ; Robinson, Kelly L. ; Richardson, T. M. ; Giesecke, R. ; Gorsky, Gabriel ; Greve, Wulf ; Halsband-Lenk, C. ; Hays, Graeme ; Hobson, V. ; Klein, David ; Lebrato, Mario ; Loveridge, Jan ; Martens, P. ; Milos, C. ; Perry, G. ; Stemmann, Lars ; Sullivan, Barbara ; Walker, T. ; Schildhauer, Mark ; Regetz, J.The Jellyfish Database Initiative (JeDI) is a scientifically-coordinated global database dedicated to gelatinous zooplankton (members of the Cnidaria, Ctenophora and Thaliacea) and associated environmental data. The database holds 476,000 quantitative, categorical, presence-absence and presence only records of gelatinous zooplankton spanning the past four centuries (1790-2011) assembled from a variety of published and unpublished sources. Gelatinous zooplankton data are reported to species level, where identified, but taxonomic information on phylum, family and order are reported for all records. Other auxiliary metadata, such as physical, environmental and biometric information relating to the gelatinous zooplankton metadata, are included with each respective entry. JeDI has been developed and designed as an open access research tool for the scientific community to quantitatively define the global baseline of gelatinous zooplankton populations and to describe long-term and large-scale trends in gelatinous zooplankton populations and blooms. It has also been constructed as a future repository of datasets, thus allowing retrospective analyses of the baseline and trends in global gelatinous zooplankton populations to be conducted in the future.
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ArticleOceanic lobate ctenophores possess feeding mechanics similar to the impactful coastal species Mnemiopsis leidyi(Association for the Sciences of Limnology and Oceanography, 2022-09-23) Cordeiro, Malaika ; Costello, John H. ; Gemmell, Brad J. ; Sutherland, Kelly R. ; Colin, Sean P.Lobate ctenophores are often numerically dominant members of oceanic epipelagic and midwater ecosystems. Despite this, little is known about their trophic ecology. Multiple, co‐occurring species are often found in these ecosystems and appear to feed similarly via feeding currents that entrain prey. We quantified the hydrodynamics, morphology, and behavior of four co‐occurring, cosmopolitan lobate species (Eurhamphaea vexilligera, Ocyropsis crystallina, Bolinopsis vitrea, and Leucothea multicornis) to evaluate whether their feeding mechanics lead to differential feeding rates and prey selection. We compared the feeding characteristics of these four oceanic species to the coastal lobate ctenophore, Mnemiopsis leidyi, which is known as a voracious zooplanktivore. We found that despite their morphological diversity, the five lobate species used the same mechanism to generate their feeding current—the hydrodynamics of their feeding currents were similarly laminar and with very low fluid deformation rates. Despite having similar feeding current traits, the species had different in situ swimming behaviors and feeding postures. We show that these different behaviors and postures lead to different prey encounter rates and that several of the oceanic species have the potential to feed at rates similar to or greater than M. leidyi. As such, the individual and combined trophic impact of oceanic lobate ctenophores is likely to be much greater than previously predicted.
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ArticlePrey capture by the cosmopolitan hydromedusae, Obelia spp., in the viscous regime(John Wiley & Sons, 2016-08-29) Sutherland, Kelly R. ; Gemmell, Brad J. ; Colin, Sean P. ; Costello, John H.Obelia spp. are cnidarian hydromedusae with a cosmopolitan distribution but very little is known about their feeding. The small size of Obelia (bell diameter ∼ 1 mm, tentacle width ∼ 0.05 mm) suggests that feeding occurs in a viscous regime characterized by thick boundary layers. During feeding observations with a natural prey assemblage the majority of prey were captured at the tentacle tips during the contraction phase. Swimming kinematics from high speed videography confirmed that swimming was a low Re number process (Re < 50) and showed that maximum tentacle velocities occurred at the tentacle tips midway through a bell contraction. Flow visualizations from particle image velocimetry demonstrated that fluid motion between the tentacles was limited and that velocities were highest at the tentacle tips, leading to a thinning of boundary layer in this region. The highest nematocyst densities were observed in this same region of the tentacle tips. Taken together, the body kinematics, flow visualizations and nematocyst distributions of Obelia explain how these predators are able to shed viscous boundary layers to effectively capture microplanktonic prey. Our findings help explain how other small feeding-current medusae whose feeding interactions are governed by viscosity are able to successfully forage.
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ArticleMulti-jet propulsion organized by clonal development in a colonial siphonophore(Nature Publishing Group, 2015-09-01) Costello, John H. ; Colin, Sean P. ; Gemmell, Brad J. ; Dabiri, John O. ; Sutherland, Kelly R.Physonect siphonophores are colonial cnidarians that are pervasive predators in many neritic and oceanic ecosystems. Physonects employ multiple, clonal medusan individuals, termed nectophores, to propel an aggregate colony. Here we show that developmental differences between clonal nectophores of the physonect Nanomia bijuga produce a division of labour in thrust and torque production that controls direction and magnitude of whole-colony swimming. Although smaller and less powerful, the position of young nectophores near the apex of the nectosome allows them to dominate torque production for turning, whereas older, larger and more powerful individuals near the base of the nectosome contribute predominantly to forward thrust production. The patterns we describe offer insight into the biomechanical success of an ecologically important and widespread colonial animal group, but, more broadly, provide basic physical understanding of a natural solution to multi-engine organization that may contribute to the expanding field of underwater-distributed propulsion vehicle design.
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PreprintFiltration of submicrometer particles by pelagic tunicates( 2010-07) Sutherland, Kelly R. ; Madin, Laurence P. ; Stocker, RomanSalps are common in oceanic waters and have higher per individual filtration rates than any other zooplankton filter feeder. Though salps are centimeters in length, feeding via particle capture occurs on a fine, mucous mesh (fiber diameter d ~ 0.1 μm) at low velocity (U = 1.6 ± 0.6 cm s-1, mean ± SD) and is thus a low-Reynolds number (Re ~ 10-3) process. In contrast to the current view that particle encounter is dictated by simple sieving of particles larger than the mesh spacing, a low-Re mathematical model of encounter rates by the salp feeding apparatus for realistic oceanic particle size distributions shows that submicron particles, due to their higher abundances, are encountered at higher rates (particles per time) than larger particles. Data from feeding experiments with 0.5, 1 and 3 μm diameter polystyrene spheres corroborate these results. Though particles larger than 1 μm (e.g. flagellates, small diatoms) represent a larger carbon pool, smaller particles in the 0.1–1 μm range (e.g. bacteria, Prochlorococcus) may be more quickly digestible because they present more surface area, and we find that particles smaller than the mesh size (1.4 μm) can fully satisfy salp energetic needs. Furthermore, by packaging submicrometer particles into rapidly sinking fecal pellets, pelagic tunicates can substantially change particle size spectra and increase downward fluxes in the ocean.
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ArticleLinking human well-being and jellyfish : ecosystem services, impacts, and societal responses(Ecological Society of America, 2014-11) Graham, William M. ; Gelcich, Stefan ; Robinson, Kelly L. ; Duarte, Carlos M. ; Brotz, Lucas ; Purcell, Jennifer E. ; Madin, Laurence P. ; Mianzan, Hermes ; Sutherland, Kelly R. ; Uye, Shin-Ichi ; Pitt, Kylie A. ; Lucas, Cathy H. ; Bogeberg, Molly ; Brodeur, Richard D. ; Condon, Robert H.Jellyfish are usually perceived as harmful to humans and are seen as “pests”. This negative perception has hindered knowledge regarding their value in terms of ecosystem services. As humans increasingly modify and interact with coastal ecosystems, it is important to evaluate the benefits and costs of jellyfish, given that jellyfish bloom size, frequency, duration, and extent are apparently increasing in some regions of the world. Here we explore those benefits and costs as categorized by regulating, supporting, cultural, and provisioning ecosystem services. A geographical perspective of human vulnerability to jellyfish over four categories of human well-being (health care, food, energy, and freshwater production) is also discussed in the context of thresholds and trade-offs to enable social adaptation. Whereas beneficial services provided by jellyfish likely scale linearly with biomass (perhaps peaking at a saturation point), non-linear thresholds exist for negative impacts to ecosystem services. We suggest that costly adaptive strategies will outpace the beneficial services if jellyfish populations continue to increase in the future.
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ArticleInk release and swimming behavior in the oceanic Ctenophore Eurhamphaea vexilligera(University of Chicago Press, 2020-06-08) Townsend, James P. ; Gemmell, Brad J. ; Sutherland, Kelly R. ; Colin, Sean P. ; Costello, John H.Of the more than 150 ctenophore species, the oceanic ctenophore Eurhamphaea vexilligera is notable for its bright orange-yellow ink, secreted from numerous small vesicles that line its substomodeal comb rows. To date, in situ observations by scuba divers have proved the most fruitful method of observing these animals’ natural behavior. We present the results of one such contemporary scuba-based observation of E. vexilligera, conducted in the Gulf Stream waters off the coast of Florida, using high-resolution photography and video. Utilizing underwater camera systems purpose built for filming gelatinous zooplankton, we observed E. vexilligera ink release and swimming behavior in situ. From these data, we describe the timeline and mechanics of E. vexilligera ink release in detail, as well as the animal’s different swimming behaviors and resulting ink dispersal patterns. We also describe a rolling swimming behavior, accompanied and possibly facilitated by a characteristic change in overall body shape. These observations provide further insight into the behavioral ecology of this distinctive ctenophore and may serve as the foundation for future kinematic studies.
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ArticleThe role of suction thrust in the metachronal paddles of swimming invertebrates(Nature Research, 2020-10-20) Colin, Sean P. ; Costello, John H. ; Sutherland, Kelly R. ; Gemmell, Brad J. ; Dabiri, John O. ; Du Clos, Kevin T.An abundance of swimming animals have converged upon a common swimming strategy using multiple propulsors coordinated as metachronal waves. The shared kinematics suggest that even morphologically and systematically diverse animals use similar fluid dynamic relationships to generate swimming thrust. We quantified the kinematics and hydrodynamics of a diverse group of small swimming animals who use multiple propulsors, e.g. limbs or ctenes, which move with antiplectic metachronal waves to generate thrust. Here we show that even at these relatively small scales the bending movements of limbs and ctenes conform to the patterns observed for much larger swimming animals. We show that, like other swimming animals, the propulsors of these metachronal swimmers rely on generating negative pressure along their surfaces to generate forward thrust (i.e., suction thrust). Relying on negative pressure, as opposed to high pushing pressure, facilitates metachronal waves and enables these swimmers to exploit readily produced hydrodynamic structures. Understanding the role of negative pressure fields in metachronal swimmers may provide clues about the hydrodynamic traits shared by swimming and flying animals.
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ArticleResilience in moving water : effects of turbulence on the predatory impact of the lobate ctenophore Mnemiopsis leidyi(John Wiley & Sons, 2017-08-14) Jaspers, Cornelia ; Costello, John H. ; Sutherland, Kelly R. ; Gemmell, Brad J. ; Lucas, Kelsey N. ; Tackett, Jennifer ; Dodge, Kara L. ; Colin, Sean P.Despite its delicate morphology, the lobate ctenophore Mnemiopsis leidyi thrives in coastal ecosystems as an influential zooplankton predator. Coastal ecosystems are often characterized as energetic systems with high levels of natural turbulence in the water column. To understand how natural wind-driven turbulence affects the feeding ecology of M. leidyi, we used a combination of approaches to quantify how naturally and laboratory generated turbulence affects the behavior, feeding processes and feeding impact of M. leidyi. Experiments using laboratory generated turbulence demonstrated that turbulence can reduce M. leidyi feeding rates on copepods and Artemia nauplii by > 50%. However, detailed feeding data from the field, collected during highly variable surface conditions, showed that wind-driven turbulence did not affect the feeding rates or prey selection of M. leidyi. Additional laboratory experiments and field observations suggest that the feeding process of M. leidyi is resilient to wind-driven turbulence because M. leidyi shows a behavioral response to turbulence by moving deeper in the water column. Seeking refuge in deeper waters enables M. leidyi to maintain high feeding rates even under high turbulence conditions generated by wind driven mixing. As a result, M. leidyi exerted a consistently high predatory impact on prey populations during highly variable and often energetic wind-driven mixing conditions. This resilience adds to our understanding of how M. leidyi can thrive in a wide spectrum of environments around the world. The limits to this resilience also set boundaries to its range expansion into novel areas.
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ThesisForm, function and flow in the plankton : jet propulsion and filtration by pelagic tunicates(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-02) Sutherland, Kelly R.Trade-offs between filtration rate and swimming performance among several salp species with distinct morphologies and swimming styles were compared. Small-scale particle encounter at the salp filtering apparatus was also explored. Observations and experiments were conducted at the Liquid Jungle Lab, off the pacific coast of Panama in January 2006 through 2009. First, time-varying body volume was calculated by digitizing salp outlines from in situ video sequences. The resulting volume flow rates were higher than previous measurements, setting an upper limit on filtration capacity. Though each species possessed a unique combination of body kinematics, normalized filtration rates were comparable across species, with the exception of significantly higher rates in Weelia cylindrica aggregates, suggesting a tendency towards a flow optimum. Secondly, a combination of in situ dye visualization and particle image velocimetry (PIV) measurements were used to describe properties of the jet wake and swimming performance variables including thrust, drag and propulsive efficiency. All species investigated swam via vortex ring propulsion. Though Weelia cylindrica was the fastest swimmer, Pegea confoederata was the most efficient, producing the highest weight-specific thrust and whole-cycle propulsive efficiency. Weak swimming performance parameters in Cyclosalpa affinis, including low weight-specific thrust and low propulsive efficiency, may be compensated by comparatively low energetic requirements. Finally, a low Reynolds number mathematical model using accurately measured parameters and realistic oceanic particle size concentrations showed that submicron particles are encountered at higher rates than larger particles. Results from feeding experiments with 0.5, 1 and 3 μm polystyrene microspheres corroborated model predictions. Though 1 to 10 μm-sized particles (e.g. flagellates, small diatoms) are predicted to provide four times as much carbon as 0.1 to 1 μm- sized particles (e.g. bacteria, Prochlorococcus), particles smaller than the mesh size (1.4 μm) can still fully satisfy salp energetic needs.
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ArticleIs global ocean sprawl a cause of jellyfish blooms?(Ecological Society of America, 2012-09-07) Duarte, Carlos M. ; Pitt, Kylie A. ; Lucas, Cathy H. ; Purcell, Jennifer E. ; Uye, Shin-Ichi ; Robinson, Kelly L. ; Brotz, Lucas ; Decker, Mary Beth ; Sutherland, Kelly R. ; Malej, Alenka ; Madin, Laurence P. ; Mianzan, Hermes ; Gili, Josep-Maria ; Fuentes, Veronica ; Atienza, Dacha ; Pages, Francesc ; Breitburg, Denise L. ; Malek, Jennafer ; Graham, William M. ; Condon, Robert H.Jellyfish (Cnidaria, Scyphozoa) blooms appear to be increasing in both intensity and frequency in many coastal areas worldwide, due to multiple hypothesized anthropogenic stressors. Here, we propose that the proliferation of artificial structures – associated with (1) the exponential growth in shipping, aquaculture, and other coastal industries, and (2) coastal protection (collectively, “ocean sprawl”) – provides habitat for jellyfish polyps and may be an important driver of the global increase in jellyfish blooms. However, the habitat of the benthic polyps that commonly result in coastal jellyfish blooms has remained elusive, limiting our understanding of the drivers of these blooms. Support for the hypothesized role of ocean sprawl in promoting jellyfish blooms is provided by observations and experimental evidence demonstrating that jellyfish larvae settle in large numbers on artificial structures in coastal waters and develop into dense concentrations of jellyfish-producing polyps.