Plenary Speaker

Larry (Laurence) P. Madin

Laurence P. Madin Larry Madin is the Executive Vice President and Director of Research, and a Senior Scientist, at the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, MA. Previously he has been Chair of the WHOI Biology Department, and Director of the WHOI Ocean Life Institute. Madin received his AB degree from the University of California, Berkeley and his PhD from UC Davis, and has been at WHOI since 1974. His principal research interests are in the biology of oceanic and deep-sea zooplankton and fishes, with special emphasis on medusae, siphonophores, ctenophores and pelagic tunicates. Madin was among the first biologists to use SCUBA and submersibles for the in-situ study of the oceanic plankton. He has participated in over 70 research cruises, serving as Chief Scientist on nearly half of them. He holds an adjunct appointment at the Monterey Bay Aquarium Research Institute, and is a member of AGU, ASLO and serves on several advisory and steering committees.

(Abstract of Plenary Talk)

Getting to know the jellies

There is evidence in the fossil record that jellyfish-like organisms have lived on earth since the Pre-Cambrian, and have probably been important components of ocean ecosystems ever since. Detailed knowledge of their systematics, physiology, behavior and ecology has emerged mainly in the last century, and particularly in the last few decades. Despite their importance for understanding the evolution of life on earth, the fragility, unpredictable distributions and lack of economic value of gelatinous animals has made their study difficult and left them outside the mainstream of biological oceanography. But recently new methods for observing, quantifying and culturing jellies have greatly increased our understanding of their diversity, life histories and role in ocean ecosystems. In-situ methods, including diving, towed cameras, submersibles and robotic vehicles have revealed the presence and abundance of medusae, siphonophores, ctenophores, thaliaceans and many other semi-gelatinous worms, mollusks, fishes, and even crustaceans throughout the world ocean. When medusae or salps occur in dense blooms they can have dramatic impacts on the rest of the community and sometimes affect human activities. Comparable population densities sometimes occur in the open and deep sea, where their impacts are unknown, but probably also dramatic. This presentation surveys the development of methods for studying gelatinous animals, and some of the resulting findings that have expanded our understanding and appreciation of the role of jellies in all parts of the ocean.


Invited Speaker 1

Rob (Robert) H. Condon

Robert H. Condon Rob Condon is a Research Senior Marine Scientist based at the Dauphin Island Sea Lab in Alabama. He is also lead PI of the Global Jellyfish Group sponsored by the National Center for Ecological Analysis and Synthesis in Santa Barbara, California, a working group formed in 2009 to examine the magnitude and extent of global jellyfish blooms and the consequences for ecosystems, biogeochemical cycles and socioeconomics. Dr. Condon's interests center around understanding the climatological, environmental and biogeochemical processes controlling zooplankton and microbial communities, the biological pump and carbon (C) cycling in coastal and open-ocean systems. His research has also focused on examining the global and regional (e.g., Deepwater Horizon accident) effects of oil spills on ecosystem metabolism and planktonic food webs, and the fate and export of oil and dispersant in marine systems. He has produced several significant publications in the fields of jellyfish ecology and oceanography, and together with colleagues from the wider scientific community, produced the Jellyfish Database Initiative (JEDI) - a global database of jellyfish abundance records for the past century and also designed as a future repository of datasets. Dr. Condon also maintains active educational outreach programs, particularly at the early childhood and elementary school levels. In 2010, he hosted the first international jellyfish art contest in conjunction with the Jellyfish ROCK outreach event, and is co-editor of a popular book on jellyfish for adults and young children. Recently, he has started the TEAMS program (Toward Elementary Advancement Module in Science) designed to teach young students the process of science and to involve them in scientific research along with developing and nurturing their interest in marine science.

(Abstract of Invited Talk 1)

NCEAS Global Jellyfish Group: Assessing current paradigm, and natural and anthropogenic drivers of long-term jellyfish populations from the 19th century to present

Concern about the deterioration of the world's oceans is supported by the decline of key ecosystems, depleted fish stocks, increased hypoxia, eutrophication, ocean acidification, and perceived increases in jellyfish blooms. While most changes have undergone global assessments, a lack of long-term information and synthesis has restricted these analyses for global jellyfish populations. The NCEAS Global Jellyfish Group was established in 2009 to achieve four main objectives: (1) to examine the hypothesis of a global expansion of jellyfish blooms, and to explore the possible drivers for this expansion; (2) to examine the effects of jellyfish blooms on the ecosystem, addressing in particular, carbon cycling, and food webs; (3) to identify current and future consequences of jellyfish blooms for tourism, industry and fisheries, including ecosystem-based management on regional and global scales; and (4) to communicate to the media and public at large of the project results. Here, we present an overview of the NCEAS project with a focus on a recent effort to analyze all available long-term data sets on jellyfish abundances from the past three centuries using linear and logistic mixed models and effect size tests. We demonstrate that while some jellyfish populations have increased regionally over time, there is no robust evidence for a substantial global increase in jellyfish. Rather, our analyses show jellyfish populations exhibit worldwide decadal oscillations, including a rising phase during the 1990s that contributed to the current paradigm. Spectral meta-analysis comparing long-term jellyfish indices with natural and anthropogenic environmental variables suggest these 'jelly cycles' are driven by natural or astronomical cycles. While we detected a weak but significant increase in jellyfish from 1970, sustained and expanded monitoring of jellyfish is required over the next two decades to elucidate to what degree anthropogenic stressors have caused a baseline shift in global jellyfish populations.


Invited Speaker 2

José Luis Acuña

José Luis Acuña José Luis Acuña was born in 1963 to a family of photographers. He did his PhD in the University of Oviedo with Prof. Ricardo Anadón, Postdoc in the University of Newfoundland with Prof. Don Deibel and works in the University of Oviedo since 1994 as Senior Lecturer in Ecology, teaching Marine Biology, Oceanography and Evolutionary Ecology. His research interests lay on the ecology of gelatinous zooplankton, on winter ocean ecology with emphasis on the dynamics of phytoplankton blooms, and on the function and conservation of coastal ecosystems. During his most recent research he has tried to import and apply simple mathematical models and experimental designs borrowed from the fields of evolutionary, behavioral and population ecology to the marine realm. In the field, He has done research on gelatinous plankton on polar and temperate seas and is currently in charge of coordinating sampling for gelatinous zooplankton during the circumglobal expedition MALASPINA 2010 aboard RV "Hespérides". He has been member of the Committee GLOBEC-Spain, and currently coordinates Oviedo's participation on the European ERASMUS MUNDUS Master Marine Biodiversity and Conservation.

(Abstract of Invited Talk 2)

Biomechanical constraints on the evolution of jellyfishes

Jellyfishes endure prey scarcity without resort to lipid storage or to highly programmed life cycles. Theory suggests that they achieve this by taking advantage of a biomechanical backdoor. Just like fishes, many jellyfishes are cruising predators that collect prey while swimming. Their foraging velocity is subject to a biomechanical tradeoff: it should be fast enough to allow for significant prey intake, but slow enough to keep the swimming costs moderate. However, fishes and jellyfishes arrive to strikingly different solutions for this tradeoff. In fishes, visual prey detection does not depend on the size of their bodies, which can therefore evolve toward streamlined, compact shapes capable of faster foraging velocities. In contrast, cruising jellyfishes are contact predators with search areas that depend on the size of their bodies. Under such circumstances, it can be shown that a jellyfish can sustain positive growth rates at arbitrarily low prey concentrations by evolving large collection surfaces sustained by gelatinous bodies, while keeping the cruising velocities very slow. The essence of this reasoning can also be applied to active filter feeding organisms and, when brought to a limit, may explain the evolution of gelatinous bodies in passive ambush feeders.