William M. Graham's research while affiliated with Theology & Sciences Institute of Florida USA and other places

Publications (98)

Article
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Ecologists and evolutionary biologists have been looking for the key(s) to the success of scyphomedusae through their long evolutionary history in multiple habitats. Their ability to generate young medusae (ephyrae) via two distinct reproductive strategies, strobilation or direct development from planula into ephyra without a polyp stage, has been...
Poster
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Introduction Zooplankton are morphologically diverse, encompassing a body composition continuum from fragile gelatinous animals to hard-bodied crustaceans, and serve as an important trophic link between primary production and fisheries. They have a variety of complex behaviors, including diel vertical migrations (DVMs), that can alter their exposur...
Article
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Coastal river-dominated oceans are physically complex, biologically productive, and intimately connected to human socioeconomic activity. The Deepwater Horizon blowout and subsequent advection of oil into coastal waters of the northern Gulf of Mexico (nGOM) highlighted the complex linkages among oceanographic processes within this river-dominated s...
Article
Large jellyfish are important consumers of plankton, fish eggs and fish larvae in heavily fished ecosystems worldwide; yet they are seldom included in fisheries production models. Here we developed a trophic network model with 41 functional groups using ECOPATH re-expressed in a donor-driven, end-to-end format to directly evaluate the efficiency of...
Article
Pelagia noctiluca is a venomous, globally distributed holoplanktonic scyphomedusa that periodically forms aggregations in coastal environments, yet little is known about its ecology and behaviour in the northern Gulf of Mexico (nGOM). Using a high resolution plankton imaging system, we describe the patch characteristics of Pelagia medusae in relati...
Article
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Jellyfish play an important role in the food web of many coastal environments but are generally considered a nuisance to scientific fieldwork and industrial and economic trades. A better understanding of how jellyfish densities and distributions are affected by environmental parameters could elucidate population trends and provide assistance in eco...
Article
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A key step toward better knowledge of the causes and mechanisms of mass occurrences (blooms) in scyphozoan jellyfish is to assess the extent of environmentally induced effects on the phenotype of different phases in their complex life cycle. Laboratory experiments were carried out to quantify the extent of environmentally induced changes in Aurelia...
Article
The Oil Pollution Act of 1990 (OPA) requires that the responsible party make the public whole for natural resource injuries attributable to an oil spill incident. We have presented our approach at establishing natural resource baseline conditions for multiple habitats in Coastal Mississippi and Alabama. This paper presents the subsequent steps that...
Article
The establishment of a defensible baseline for ecosystem productivity is important in Natural Resource Damage Assessment (NRDA) and other assessment studies so that an estimate of the ecosystem injury can be established. In order to establish the overall NRDA baseline productivity for the Deepwater Horizon Oil release (DWH), the EPA fate and effect...
Article
Lobster phyllosoma are known to associate with large cnidarian medusae; however, direct quantitative observations are difficult because gelatinous zooplankton are extremely fragile, and the phyllosoma easily detach from their host when sampled by plankton nets. We provide the first large scale quantitative information of the distribution of this as...
Article
Estuarine-shelf exchange can drive strong gradients in physical and biogeochemical properties in the coastal zone and exert a significant influence on biological processes and patterns. Physical, biogeochemical, and plankton data from an across-shelf transect extending south of Mobile Bay, Alabama, in conjunction with regional time series data, wer...
Article
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Despite the speculations that jellyfish (hydromedusae, siphonophores, scyphomedusae and ctenophores) may compete with forage fish for prey, there are few direct comparisons of their diets. To determine the dietary overlap between Aurelia sp. (Cnidaria, Scyphozoa) and Brevoortia patronus (Goode, 1878) (Pisces, Clupeidae) in the northern Gulf of Mexi...
Data
List of sequences obtained from Genbank used in this study. (DOCX)
Data
Variation in individual size-independent morphological features of Aurelia from the Gulf of Mexico. (DOCX)
Data
Summary of the AMOVA based on COI for Aurelia sp.9 and Aurelia sp.12 in the Gulf of Mexico. (DOCX)
Data
Pairwise genetic divergence among Aurelia species based on COI. (DOCX)
Data
Morphological variation in Aurelia from the Gulf of Mexico based on meristic features. (DOCX)
Article
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For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gr...
Data
Morphological features recorded per Aurelia medusa in this study. (DOCX)
Data
Network tree based on COI for Aurelia sp. 9 and Aurelia c.f. sp. 2 in the Gulf of Mexico. (DOCX)
Poster
Full-text available
Marine snow is a ubiquitous yet morphologically and compositionally diverse constituent of the water column that plays a key role in the carbon cycle. Under certain physical circumstances, marine snow can aggregate and form thin layers, potentially serving as “trophic hotspots” of increased grazing activity. If oil is present, then marine snow thin...
Article
The relative importance of behavior and currents in forming and maintaining jellyfish aggregations is not completely understood; the objective of this work was to determine how the physical properties of the water column were related to the formation of hollow aggregations of moon jellyfish (Aurelia spp.). Hollow aggregations were observed near the...
Article
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Parasites are known to induce phenotypic modifications in their hosts through direct competition for resources, which can negatively affect host fitness. Although parasite-induced phenotypic variation has been studied extensively in terrestrial and freshwater taxa, this phenomenon remains comparatively under-studied in marine pelagic invertebrates,...
Article
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Evaluating energy flows through jellyfish and gulf menhaden (Brevoortia patronus) and the effects of fishing on the northern Gulf of Fishery management production models tend to stress only the elements directly linked to fish (i.e. fish, fish food, and fish predators). Large coastal jellyfish are major consumers of plankton in heavily fished ecosy...
Article
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A majority of the world’s largest net-based fisheries target planktivorous forage fish that serve as a critical trophic link between the plankton and upper-level consumers such as large predatory fishes, seabirds, and marine mammals. Because the plankton production that drives forage fish also drives jellyfish production, these taxa often overlap i...
Article
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The response of mesozooplankton community structure to the Deepwater Horizon oil spill in the northern Gulf of Mexico was investigated using data from a long-term plankton survey off the coast of Alabama (USA). Environmental conditions observed in the study area during the oil spill (2010) were compared to historical observations (2005–2009), to su...
Article
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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, freq...
Article
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AimScientific debate regarding the future trends, and subsequent ecological, biogeochemical and societal impacts, of gelatinous zooplankton (GZ) in a changing ocean is hampered by lack of a global baseline and an understanding of the causes of biogeographic patterns. We address this by using a new global database of GZ records to test hypotheses re...
Article
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Application of stable isotope analysis (SIA) in jellyfish allows definition of trophic patterns not detectable using gut content analysis alone, but analytical protocols require standardization to avoid bias in interpreting isotopic data. We determined δ13C and δ15N in Aurelia sp. from the northern Gulf of Mexico (30°00′N, 89°00′W–30°24′N, 88°00′W)...
Article
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Ichthyoplankton identification is a time-consuming task, and often larvae cannot be identified to species due to a lack of adequate early life history descriptions. As a result, ichthyoplankton assemblage data are often analyzed at the family level, which results in a loss of taxonomic resolution, or at mixed taxonomic levels (e. g. family, genus a...
Article
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Veliko Jezero (Mljet, Croatia) is a nearly enclosed karstic depression filled with saltwater, where jellyfish and prey exchange with the Adriatic Sea is negligible, making this small ecosystem ideal for the controlled study of medusae in food webs. Based on the analysis of their gut contents, medusae appeared to ingest less carbon than expected on...
Article
The marine jellyfishes (herein referring to pelagic scyphozoans, hydrozoans, and ctenophores) have been increasingly recognized as important nuisance species in ecosystems around the world, impacting fisheries, injuring swimmers, and clogging the intakes of power plants, among other effects. These animals have independently evolved life history and...
Article
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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, an...
Article
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A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jell...
Article
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Variability in northern Gulf of Mexico Chrysaora sp. and Aurelia spp. abundance and distribution over time and in relation to climate forces operating at large and regional scales was analyzed using two multi-decadal data sets derived from trawl data collected during fisheries-independent surveys conducted each summer (1987–2007) and fall (1985–200...
Article
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Seasonal blooms of the scyphozoan jellyfish Aurelia sp. in the northern Gulf of Mexico broadly overlap with summer-fall hypoxia of the Louisiana–Texas shelf. It has been suggested previously that increased cultural eutrophication and hypoxia promote outbreaks of jellyfish by favoring the medusa stage of scyphozoans, since hypoxia affects their prey...
Article
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Large population fluctuations of jellyfish occur over a variety of temporal scales, from weekly to seasonal, inter-annual and even decadal, with some regions of the world reported to be experiencing persistent seasonal bloom events. Recent jellyfish research has focussed on understanding the causes and consequences of these population changes, with...
Article
Following the Deepwater Horizon disaster, the effect of weathering on surface slicks, oil-soaked sands, and oil-covered rocks and boulders was studied for 18 months. With time, oxygen content increased in the hydrocarbon residues. Furthermore, a weathering-dependent increase of an operationally defined oxygenated fraction relative to the saturated...
Article
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An unusual number of near term and neonatal bottlenose dolphin (Tursiops truncatus) mortalities occurred in the northern Gulf of Mexico (nGOM) in 2011, during the first calving season after two well documented environmental perturbations; sustained cold weather in 2010 and the Deepwater Horizon oil spill (DWHOS). Preceding the stranding event, larg...
Article
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The jellyfish Drymonema larsoni bloomed in the northern Gulf of Mexico in the Fall of 2000 and fed voraciously on the moon jellyfish Aurelia sp., especially where they were concentrated in frontal convergence. We evaluated the predation potential of D. larsoni on Aurelia sp. medusa using laboratory and field data. Our data set represents the most c...
Article
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Investigations of the spatial and temporal structure of larval fish assemblages are essential for a better understanding of the dynamics of fish populations and their resilience to environmental change. This study provides an original typology of the spatial, seasonal, and depth-related structure of ichthyoplankton assemblages collected along a 77-...
Article
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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...
Article
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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 be heading toward being dominated by “nuisance” jellyfish. We question this current parad...
Article
Full-text available
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 be heading toward being dominated by “nuisance” jellyfish. We question this current parad...
Article
Full-text available
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, an...
Conference Paper
The Deepwater Horizon (DWH) oil spill was unprecedented in virtually all measures of magnitude and duration of petroleum hydrocarbon loadings to the northern Gulf of Mexico. One of the lesser considered consequences of the release is the total load of organic carbon to an extremely productive system. Without minimizing the potential toxicological c...
Article
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The rhizostome jellyfish Mastigias (Agassiz, 1862), native to the western and central Indo-Pacific, is recorded from the western Atlantic, in a marine lake in Puerto Rico (Laguna Joyuda) and a working quarry on No Name Key, Florida (USA) in the Florida Keys. The single individual from Laguna Joyuda, collected in 2002, was previously misidentified a...
Article
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Jellyfish blooms occur in many estuarine and coastal regions and may be increasing in their magnitude and extent worldwide. Voracious jellyfish predation impacts food webs by converting large quantities of carbon (C), fixed by primary producers and consumed by secondary producers, into gelatinous biomass, which restricts C transfer to higher trophi...
Article
Hydrographic variability on the Alabama shelf just outside of Mobile Bay, a major source of river discharge into the Gulf of Mexico, is examined using time series of water column temperature and surface and bottom salinity from a mooring site with a depth of 20m in conjunction with a series of across-shelf CTD surveys. The time series data show var...
Article
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Comparisons were made between ichthyoplankton samples collected in the northern Gulf of Mexico using a Bedford Institute of Oceanography Net Environmental Sampling System (BIONESS) fitted with 0.202 mm and 0.333 mm mesh plankton nets. Tow duration, tow speed, filtration efficiency and filtration rate were monitored in real time during paired obliqu...
Article
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A Great Blue Heron (Ardea herodias) foraging on an Atlantic Stingray (Dasyatis sabina) was observed off coastal Mississippi. Although elasmobranchs have been previously reported in the diets of birds, this observation was the first documenting the attack and consumption behavior by a bird on an elasmobranch. The behaviors in the event mirror previo...
Article
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We investigated the influence of climatic and environmental factors on interannual variations in juvenile abundances of marine fishes in a river-dominated coastal system of the north-central Gulf of Mexico, where an elevated primary productivity sustains fisheries of high economic importance. Fish were collected monthly with an otter trawl at three...