Browsing by Author "Gonzalez, Karina"

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    Holocene interactions between marine nomads and their coastal landscape in the Strait of Magellan, southern Patagonia: Ichthyoarchaeological and isotopic evidence
    (2024) Torres, Jimena; Gonzalez, Karina; Santana-Sagredo, Francisca; Andrade, Claudia; Roman, Manuel San; Harrod, Chris
    Marked environmental changes occurred in the southern Patagonian archipelago during the middle and late Holocene, including increased variability in glacial coverage and marine productivity. Those changes likely impacted the lives of marine hunter gatherers and their exploitation of faunal resources. Here, we examine temporal trends in fishes captured during the mid- and late Holocene, including variation in stable isotope values (delta 13C and delta 15N) of the most commonly exploited taxa to explore potential changes in fishing strategies due to environmental and cultural causes. We examined fish remains from eight archaeological sites and cultural periods in the Strait of Magellan. The ichthyoarchaeological results indicate drastic changes in the assemblages of fishes captured, with demersal species dominating catches before 2700 cal. yr BP and a subsequent switch to coastal fishes associated with subtidal kelp forests afterwards until 500 cal yr BP, both in the Strait of Magellan and adjacent seas. Although limited by sample sizes, our isotopic data show little obvious variation in Eleginops maclovinus over the different periods. However, Patagonotothen sp. and Salilota australis displayed significant isotopic shifts during the Holocene, but followed distinct, taxon-specific trajectories. This suggests that responses to the late Holocene environmental changes differed between species. This study also contributes to the baseline ecological information prior to the impact of modern industrial fishing practices with data from native fishes that are important components in kelp forests (Macrocystis pyrifera) ecosystems of the sub-Antarctic region.
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    Pan genome of the phytoplankton Emiliania underpins its global distribution
    (2013) Read, Betsy A.; Kegel, Jessica; Klute, Mary J.; Kuo, Alan; Lefebvre, Stephane C.; Maumus, Florian; Mayer, Christoph; Miller, John; Monier, Adam; Salamov, Asaf; Young, Jeremy; Aguilar, Maria; Claverie, Jean-Michel; Frickenhaus, Stephan; Gonzalez, Karina; Herman, Emily K.; Lin, Yao-Cheng; Napier, Johnathan; Ogata, Hiroyuki; Sarno, Analissa F.; Shmutz, Jeremy; Schroeder, Declan; de Vargas, Colomban; Verret, Frederic; von Dassow, Peter; Valentin, Klaus; Van de Peer, Yves; Wheeler, Glen; Dacks, Joel B.; Delwiche, Charles F.; Dyhrman, Sonya T.; Gloeckner, Gernot; John, Uwe; Richards, Thomas; Worden, Alexandra Z.; Zhang, Xiaoyu; Grigoriev, Igor V.; Allen, Andrew E.; Bidle, Kay; Borodovsky, M.; Bowler, C.; Brownlee, Colin; Cock, J. Mark; Elias, Marek; Gladyshev, Vadim N.; Groth, Marco; Guda, Chittibabu; Hadaegh, Ahmad; Iglesias-Rodriguez, Maria Debora; Jenkins, J.; Jones, Bethan M.; Lawson, Tracy; Leese, Florian; Lindquist, Erika; Lobanov, Alexei; Lomsadze, Alexandre; Malik, Shehre-Banoo; Marsh, Mary E.; Mackinder, Luke; Mock, Thomas; Mueller-Roeber, Bernd; Pagarete, Antonio; Parker, Micaela; Probert, Ian; Quesneville, Hadi; Raines, Christine; Rensing, Stefan A.; Riano-Pachon, Diego Mauricio; Richier, Sophie; Rokitta, Sebastian; Shiraiwa, Yoshihiro; Soanes, Darren M.; van der Giezen, Mark; Wahlund, Thomas M.; Williams, Bryony; Wilson, Willie; Wolfe, Gordon; Wurch, Louie L.
    Coccolithophores have influenced the global climate for over 200 million years(1). These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems(2). They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering them visible from space(3). Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO2 production or uptake, sequestration and export to the deep ocean(4). Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate that E. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.