Graham
William M.
Graham
William M.
No Thumbnail Available
Search Results
Now showing
1 - 6 of 6
-
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.
-
ArticleFloating oil-covered debris from Deepwater Horizon : identification and application(IOP Publishing, 2012-01-18) Carmichael, Catherine A. ; Arey, J. Samuel ; Graham, William M. ; Linn, Laura J. ; Lemkau, Karin L. ; Nelson, Robert K. ; Reddy, Christopher M.The discovery of oiled and non-oiled honeycomb material in the Gulf of Mexico surface waters and along coastal beaches shortly after the explosion of Deepwater Horizon sparked debate about its origin and the oil covering it. We show that the unknown pieces of oiled and non-oiled honeycomb material collected in the Gulf of Mexico were pieces of the riser pipe buoyancy module of Deepwater Horizon. Biomarker ratios confirmed that the oil had originated from the Macondo oil well and had undergone significant weathering. Using the National Oceanic and Atmospheric Administration's records of the oil spill trajectory at the sea surface, we show that the honeycomb material preceded the front edge of the uncertainty of the oil slick trajectory by several kilometers. We conclude that the observation of debris fields deriving from damaged marine materials may be incorporated into emergency response efforts and forecasting of coastal impacts during future offshore oil spills, and ground truthing predicative models.
-
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.
-
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.
-
PreprintOrientation and swimming mechanics by the scyphomedusa Aurelia sp. in shear flow( 2006) Rakow, Kelly C. ; Graham, William M.Individual Aurelia sp. medusae were distributed around regions of current shear associated with vertical density discontinuities during three vertically towed camera profiles in the northern Gulf of Mexico. Along shear regions, medusae oriented non-randomly and swam horizontally, forming distinct layers. To identify the mechanisms by which Aurelia maintain horizontal orientation in velocity shear, jellyfish swimming mechanics were studied in laboratory kreisel tanks at three shear rates (0.10, 0.21, and 0.34 s-1) and a no flow control. Medusae counteracted the rotational effect of velocity shear by pulsing asymmetrically. Specifically, medusae held a position against shear flow by maintaining a higher bell margin angle on the side of the medusa in higher flow velocity. Swimming asymmetry increased with shear and, as a result, the ratio between bell angles on opposing flow sides was significantly different from the control at all shear rates. Contractions were initiated on the lower flow side of the bell in all cases and at the highest shear rate, the low flow side of the bell contracted 0.2 s before the high flow side. Laboratory observations confirm that patches of jellyfish at vertical discontinuities may be the result of an active behavioral response to vertical velocity shear. Layers of jellyfish formed via an active behavioral response to shear may improve prey encounter or fertilization success.
-
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.