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Northern Florida (northern + florida)

Distribution by Scientific Domains

Life Sciences	60%

Selected Abstracts

Polychlorinated biphenyls, organochlorine pesticides, tris(4-chlorophenyl)methane, and tris(4-chlorophenyl)methanol in livers of small cetaceans stranded along Florida coastal waters, USA

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2000
Mafumi Watanabe
Abstract Concentrations of polychlorinated biphenyl congeners (PCBs) and organochlorine pesticides were determined in the livers of bottlenose dolphins, Atlantic spotted dolphins, and pygmy sperm whales found stranded along the coastal waters of Florida, USA, during 1989 to 1994. The PCBs were the most predominant contaminants followed in order by DDTs, chlordanes, tris(4-chlorophenyl)methane (TCPMe), tris(4-chlorophenyl)methanol (TCPMOH), hexachlorobenzene, and hexachlorocyclohexane isomers. Among the cetaceans analyzed, organochlorine concentrations were greatest in bottlenose dolphins followed by Atlantic spotted dolphins and pygmy sperm whales. Hexa- and heptachlorobiphenyls were the predominant PCB congeners found in the livers of dolphins. Patterns of relative concentrations of PCB congeners varied among individual bottlenose dolphins. A few individuals contained predominant concentrations of octa- (CB-199, 196/201) and nonachlorobiphenyl (CB-206, 208) congeners, which suggested exposure to the highly chlorinated PCB formulation, Aroclor® 1268, a contaminant at a coastal site in Georgia bordering northern Florida. The estimated 2,3,7,8-tetrachlorodibenzo- p -dioxin toxic equivalents (TEQs) of coplanar PCBs in bottlenose dolphins were 170 to 18,000 pg/g, lipid weight (mean: 5,400 pg/g) with mono- ortho congeners 118, 105, and 156 contributing more than 80% of the TEQs. The ratios of CB-169 to CB-126 in cetacean livers were linearly related to total PCB concentrations, which suggested a strong induction of microsomal monooxygenase enzymes in the liver. The hepatic concentrations of TCPMe and TCPMOH in bottlenose dolphins and Atlantic spotted dolphins were greater than those in the blubber of marine mammals of various regions, which suggested the presence of sources for these chemicals along the Atlantic coast of Florida. [source]

Local- to continental-scale variation in the richness and composition of an aquatic food web

GLOBAL ECOLOGY, Issue 5 2010
Hannah L. Buckley
ABSTRACT Aim, We investigated patterns of species richness and composition of the aquatic food web found in the liquid-filled leaves of the North American purple pitcher plant, Sarracenia purpurea (Sarraceniaceae), from local to continental scales. Location, We sampled 20 pitcher-plant communities at each of 39 sites spanning the geographic range of S. purpurea, from northern Florida to Newfoundland and westward to eastern British Columbia. Methods, Environmental predictors of variation in species composition and species richness were measured at two different spatial scales: among pitchers within sites and among sites. Hierarchical Bayesian models were used to examine correlates and similarities of species richness and abundance within and among sites. Results, Ninety-two taxa of arthropods, protozoa and bacteria were identified in the 780 pitcher samples. The variation in the species composition of this multi-trophic level community across the broad geographic range of the host plant was lower than the variation among pitchers within host-plant populations. Variation among food webs in richness and composition was related to climate, pore-water chemistry, pitcher-plant morphology and leaf age. Variation in the abundance of the five most common invertebrates was also strongly related to pitcher morphology and site-specific climatic and other environmental variables. Main conclusions, The surprising result that these communities are more variable within their host-plant populations than across North America suggests that the food web in S. purpurea leaves consists of two groups of species: (1) a core group of mostly obligate pitcher-plant residents that have evolved strong requirements for the host plant and that co-occur consistently across North America, and (2) a larger set of relatively uncommon, generalist taxa that co-occur patchily. [source]

Upper Albian ammonites from ODP Leg 171B off northern Florida

PALAEONTOLOGY, Issue 1 2000
Jens Lehmann
ODP Leg 171B investigated the sediments of the Blake Plateau off northern Florida and recovered 36 Upper Albian ammonites , one from Site 1050C, the others from Site 1052E. This unusually large number of specimens from an ODP site permits the dating of the interval between 668 to 621 m below sea-floor at Site 1052E as late Late Albian, Stoliczkaia (S.) dispar ammonite zone. This zone is indicated by the genera Mortoniceras and Stoliczkaia (S.). Site 1050C (Interval 171B-1050C-31R-3, 0.80,0.86 m) cannot be dated more precisely than Late Aptian to Mid Cenomanian by ammonites. The fauna is cosmopolitan. Tetragonites jurinianusPuzosia mayoriana are widely distributed forms. Kossmatella muhlenbecki was thought to be restricted to a fairly small area around the Mediterranean, but the record off northern Florida presented here, indicates that it is not an endemic species; this is also true for Hemiptychoceras subgaultinum in the Albian. The event-like character of the ammonite-bearing interval at Site 1052E is unique. It is overlain by a laminated claystone succession; the top of this sequence is considered to represent maximum flooding (Oceanic Anoxic Event, OAE 1d). Ammonites perhaps profited from an increased nutrient supply derived from flooded coastal plains during a continuous transgression. [source]

Spanish colonial effects on Native American mating structure and genetic variability in northern and central Florida: Evidence from Apalachee and western Timucua

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2005
Christopher M. Stojanowski
Abstract Standard population genetic analyses are implemented for a series of precontact and contact period samples from central and northern Florida to investigate changes in genetic variability and population affinity coincident with the establishment of Spanish missions during the 17th century. Estimates of FST based on odontometric data indicate limited heterogeneity for the Apalachee samples, suggestive of some degree of within-group endogamy for this ethnic group prior to contact. This corresponds well with ethnohistoric reconstructions indicating that Apalachee were populous, partially linguistically isolated from its neighbors, and involved in persistent cycles of warfare with neighboring groups. Estimates of extralocal gene flow for the Apalachee samples indicate limited initial changes in the mating structure of these populations. After 1650, however, extralocal gene flow increases, consistent with evidence for dramatic population movements throughout northern Florida and increased Spanish presence in the province, particularly at the mission of San Luis. Inclusion of non-Apalachee outgroups does not increase estimates of genetic heterogeneity, as was expected based on ethnohistoric data. The pattern of genetic distances suggests a biological division between north and south Florida population groups, consistent with archaeological and ethnohistoric data, and similarly indicates some distinction between precontact and postcontact local groups. Differential extralocal gene flow experienced by pre-1650 Apalachee and Timucua populations suggests localized mission experience. The Apalachee, with large, dense populations, experienced limited initial changes in genetic diversity or mating structure. However, after 1650 they were apparently involved in a much more expansive mating network that may have included Spaniards and immigrant Native American groups to the region. These results are in contrast to the mission experience of the Guale Indians of the Georgia coast. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc. [source]