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Temporal Variation in Fish Mercury Concentrations within Lakes from the Western Aleutian Archipelago, Alaska  [PDF]
Leah A. Kenney, Collin A. Eagles-Smith, Joshua T. Ackerman, Frank A. von Hippel
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0102244
Abstract: We assessed temporal variation in mercury (Hg) concentrations of threespine stickleback (Gasterosteus aculeatus) from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37–1.07 μg/g dry weight (dw), with a mean (± SE) of 0.55±0.01 μg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57±0.01 μg/g dw in early June to 0.52±0.01 μg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56±0.01 μg/g dw) than in Lake 696 (0.53±0.01 μg/g dw), and 4% higher in males (0.56±0.01 μg/g dw) than in females (0.54±0.01 μg/g dw). Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife.
Waterbird occurrence and abundance in the Strobel Plateau, Patagonia, Argentina
Lancelotti,Julio L.; Pozzi,Luciana M.; Márquez,Federico; Yorio,Pablo; Pascual,Miguel A.;
El hornero , 2009,
Abstract: the strobel plateau is a conspicuous and representative basaltic plateau ("meseta") in the patagonian steppe, argentina. this plateau is dotted with more than 1500 shallow lakes, which are regularly used by waterbirds and support one of the main breeding populations of the near threatened hooded grebe (podiceps gallardoi). we collected data on bird presence and abundance in 41 shallow lakes, covering a wide spectrum of the wetland environmental variability found in the area. we conducted six surveys from spring to fall between 2004 and 2006. we recorded a total of 18 waterbird species, which represent 5 different families. anatidae was the family most represented with 12 species, accounting for 85% of the observed waterbirds. waterbird distribution among lakes was variable, from 2.4% occupied lakes for wilson's phalarope (steganopus tricolor) and andean ruddy-duck (oxyura jamaicensis) to 80% for black-necked swan (cygnus melanocorypha), and abundance varied greatly both between species and seasons. the hooded grebe, in particular, was recorded in 14 lakes (1-81 individuals). six species were detected breeding in the area: hooded grebe, silvery grebe (podiceps occipitalis), flying steamer-duck (tachyeres patachonicus), crested duck (anas specularioides), upland goose (chloephaga picta), and white-winged coot (fulica leucoptera). the hooded grebe nested at four lakes, three of them not previously known to hold breeding birds. results point to the need of further studies on the dynamic nature of waterbird lake use to adequately assess the importance of the strobel plateau as waterbird habitat.
Archipelago groups  [PDF]
Gregory R. Conner,Wolfram Hojka,Mark Meilstrup
Mathematics , 2014,
Abstract: The classical archipelago is a non-contractible subset of $\mathbb{R}^3$ which is homeomorphic to a disk except at one non-manifold point. Its fundamental group, $\mathcal{A}$, is the quotient of the topologist's product of $\mathbb Z$, the fundamental group of the shrinking wedge of countably many copies of the circle (the Hawaiian earring), modulo the corresponding free product. We show $\mathcal{A}$ is locally free, not indicable, and has the rationals both as a subgroup and a quotient group. Replacing $\mathbb Z$ with arbitrary groups yields the notion of archipelago groups. Surprisingly, every archipelago of countable groups is isomorphic to either $\mathcal{A}(\mathbb Z)$ or $\mathcal{A}(\mathbb Z_2)$, the cases where the archipelago is built from circles or projective planes respectively. We conjecture that these two groups are isomorphic and prove that for large enough cardinalities of $G_i$, $\mathcal{A}(G_i)$ is not isomorphic to either.
Reading the archipelago
Chris Bongie
New West Indian Guide , 1999,
Abstract: [First paragraph] A History of Literature in the Caribbean, Volume 3: Cross-Cultural Studies. JAMES A. ARNOLD (ed.). Philadelphia: John Benjamins, 1997. xvii + 399 pp. (Cloth US$ 120.00) The Other America: Caribbean Literature in a New World Context. J. MICHAEL DASH. Charlottesville: University of Virginia Press, 1998. xii + 197 pp. (Cloth US$ 42.50, Paper US$ 18.50) In his most recent theoretical work, Traite du Tout-Monde, Edouard Glissant stresses the virtues of what he calls "archipelagic thinking." "The entire world is becoming an archipelago," he asserts (1997:194), and for this reason we need to distance ourselves from both insular and continental ways of thinking if we are to register the complexities of that global creolization process. The archipelago is situated between the solitary confines of the islands that constitute it and the expansive territory of the mainland toward which it points, relating the one to the other while retaining its own indeterminately distinct identity. For Glissant, actual archipelagos such as the Caribbean are exemplary sites for understanding the complex new relations that ambivalently and chaotically join together all the hitherto unconnected parts of the world. As a consequence of this, the need for understanding the Caribbean as an archipelago becomes ever more pressing: the Caribbean must be considered in its archipelagic totality, as a region that can only be adequately understood through comparative, cross-cultural analysis focusing less on its discrete parts than on the way these parts exist in relation with and to one another.
Envisioning the Archipelago  [PDF]
Stratford Elaine,Baldacchino Godfrey,Farbotko Carol,Harwood, Andrew
Island Studies Journal , 2011,
Abstract: Certain limitations arise from the persistent consideration of two common relations of islands in the humanities and social sciences: land and sea, and island and continent/mainland. What remains largely absent or silent are ways of being, knowing and doing—ontologies, epistemologies and methods—that illuminate island spaces as inter-related, mutually constituted and co-constructed: as island and island. Therefore, this paper seeks to map out and justify a research agenda proposing a robust and comprehensive exploration of this third and comparatively neglected nexus of relations. In advancing these aims, the paper’s goal is to (re)inscribe the theoretical, metaphorical, real and empirical power and potential of the archipelago: of seas studded with islands; island chains; relations that may embrace equivalence, mutual relation and difference in signification.
Cossidae of the Socotra Archipelago (Yemen)  [cached]
Robert Borth,Povilas Ivinskis,Aidas Saldaitis,Roman Yakovlev
ZooKeys , 2011, DOI: 10.3897/zookeys.122.1213
Abstract: The taxonomy of the family Cossidae (Lepidoptera) of the Socotra Archipelago is revised. Five species are recognized, including two new species (Mormogystia brandstetteri and Meharia hackeri), and dubious identifications and records are discussed. Adults and genitalia are illustrated and bionomic details, molecular evidence and a synonymic checklist of Socotra Cossidae genera is provided. A review of their distribution reveals that at least 80 percent of Socotro`s Cossidae species are unique to the archipelago which is renowned for its endemism.
Land Cover and Rainfall Interact to Shape Waterbird Community Composition  [PDF]
Colin E. Studds, William V. DeLuca, Matthew E. Baker, Ryan S. King, Peter P. Marra
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0035969
Abstract: Human land cover can degrade estuaries directly through habitat loss and fragmentation or indirectly through nutrient inputs that reduce water quality. Strong precipitation events are occurring more frequently, causing greater hydrological connectivity between watersheds and estuaries. Nutrient enrichment and dissolved oxygen depletion that occur following these events are known to limit populations of benthic macroinvertebrates and commercially harvested species, but the consequences for top consumers such as birds remain largely unknown. We used non-metric multidimensional scaling (MDS) and structural equation modeling (SEM) to understand how land cover and annual variation in rainfall interact to shape waterbird community composition in Chesapeake Bay, USA. The MDS ordination indicated that urban subestuaries shifted from a mixed generalist-specialist community in 2002, a year of severe drought, to generalist-dominated community in 2003, of year of high rainfall. The SEM revealed that this change was concurrent with a sixfold increase in nitrate-N concentration in subestuaries. In the drought year of 2002, waterbird community composition depended only on the direct effect of urban development in watersheds. In the wet year of 2003, community composition depended both on this direct effect and on indirect effects associated with high nitrate-N inputs to northern parts of the Bay, particularly in urban subestuaries. Our findings suggest that increased runoff during periods of high rainfall can depress water quality enough to alter the composition of estuarine waterbird communities, and that this effect is compounded in subestuaries dominated by urban development. Estuarine restoration programs often chart progress by monitoring stressors and indicators, but rarely assess multivariate relationships among them. Estuarine management planning could be improved by tracking the structure of relationships among land cover, water quality, and waterbirds. Unraveling these complex relationships may help managers identify and mitigate ecological thresholds that occur with increasing human land cover.
On the homology of the Harmonic Archipelago  [PDF]
Umed H. Karimov,Du?an Repov?
Mathematics , 2012, DOI: 10.2478/s11533-012-0038-2
Abstract: We calculate the singular homology and \v{C}ech cohomology groups of the Harmonic archipelago. As a corollary, we prove that this space is not homotopy equivalent to the Griffiths space. This is interesting in view of Eda's proof that the first singular homology groups of these spaces are isomorphic.
The fundamental group of the harmonic archipelago  [PDF]
Paul Fabel
Mathematics , 2005,
Abstract: The harmonic archipelago HA is obtained by attaching a large pinched annulus to every pair of consecutive loops of the Hawaiian earring. We clarify the fundamental group pi1(HA) as a quotient of the Hawaiian earring group, provide a precise description of the kernel, show that both pi1(HA) and the kernel are uncountable, and that pi1(HA) has the indiscrete topology.
Spawning areas, dispersion and microhabitats of fish larvae in the Anavilhanas Ecological Station, rio Negro, Amazonas State, Brazil
Oliveira, Edinbergh C. de;Ferreira, Efrem J. G.;
Neotropical Ichthyology , 2008, DOI: 10.1590/S1679-62252008000400003
Abstract: the abundance and distribution of ichthyoplankton and their relationships to current velocity, temperature, dissolved oxygen, ph and electrical conductivity of the water in the anavilhanas ecological station, negro river, amazonas state, brazil, were analyzed. preferred microhabitats for spawning, dispersion and nursery were also verified. sampling was undertaken during the falling water period of 2001 and the rising water period of 2002, in a section of 100 km subdivided into 5 subsections, with a total of 20 stations (5 beaches, 5 ravines, 5 channels, and 5 lake channels) at night and during the day at the surface and at the bottom. 647 eggs and 4,187 larvae were captured, belonging to 10 families and four orders: characiformes (6), siluriformes (2), perciformes (1), and clupeiformes (1). engraulidae (55.39%), pimelodidae (30.45%), auchenipteridae (5.23%) and sciaenidae (5.13%) were the dominant families. the hierarchical statistical model (anova) with three factors (microhabitat, depth and period) was applied to the environmental variables and the larval abundance, showing greater abundances of sciaenids in the ravines and lower abundances of engraulids in the channels. the highest captures were obtained at lower temperature values, at the bottom during the day and at the surface at night, suggesting an active larval behavior. the presence of the four larval development stages in all subsection for pimelodids and sciaenids, and in three subsections for engraulids, indicates that the anavilhanas ecological station is an important spawning and nursery area for species of these groups in the negro river. larvae abundance of all characiform families was extremely low (from 0.1 to 1.17%), suggesting that they do not spawn in this system.
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