Browsing by Subject "Marine & Freshwater Biology"

Now showing 1 - 7 of 7
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    Counterpoint to Obura
    (ICES Journal of Marine Science, 2018-05-01) Basurto, Xavier
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    Emergent productivity regimes of river networks
    (Limnology and Oceanography Letters, 2019-10) Koenig, LE; Helton, AM; Savoy, P; Bertuzzo, E; Heffernan, JB; Hall, RO; Bernhardt, ES
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    Hydro-geomorphic perturbations on the soil-atmosphere CO2exchange: How (un)certain are our balances?
    (Water Resources Research, 2017-02) Dialynas, Yannis G; Bras, Rafael L; deB. Richter, Daniel
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    Linking MPA effectiveness to the future of local rural fishing societies
    (ICES Journal of Marine Science, 2018-05-01) Basurto, Xavier
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    Seabird trophic position across three ocean regions tracks ecosystem differences
    (Frontiers in Marine Science, 2018-09-07) Gagné, TO; Hyrenbach, KD; Hagemann, ME; Bass, OL; Pimm, SL; MacDonald, M; Peck, B; Van Houtan, KS
    We analyze recently collected feather tissues from two species of seabirds, the sooty tern (Onychoprion fuscatus) and brown noddy (Anous stolidus), in three ocean regions (North Atlantic, North Pacific, and South Pacific) with different human impacts. The species are similar morphologically and in the trophic levels from which they feed within each location. In contrast, we detect reliable differences in trophic position amongst the regions. Trophic position appears to decline as the intensity of commercial fishing increases, and is at its lowest in the Caribbean. The spatial gradient in trophic position we document in these regions exceeds those detected over specimens from the last 130 years in the Hawaiian Islands. Modeling suggests that climate velocity and human impacts on fish populations strongly align with these differences.
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    Suspended Sediment Mineralogy and the Nature of Suspended Sediment Particles in Stormflow of the Southern Piedmont of the USA
    (Water Resources Research, 2019-01-01) River, M; Richardson, CJ
    The majority of annual sediment flux is transported during storm events in many watersheds across the world. Using X-ray diffraction, we analyzed the mineralogy of grab samples of suspended sediment during different stages of storm hydrographs in the Southern Piedmont. Mineralogy of suspended sediment changes drastically from quartz-dominated during the rising limb to clay dominated during the late falling limb/baseflow. Changes in mineralogy can shed insight into turbidity relationships, suspended sediment sources, energy versus supply-limited sediment transport, and other suspended sediment parameters such as anion exchange capacity and trace element chemistry. An unexpected key finding, confirmed by X-ray diffraction and electron microscopy, is that both kaolinite and quartz are primarily transported as discrete crystalline minerals of different size classes in our watersheds; this contrasts with existing scientific literature stating that in most fluvial systems suspended sediment is transported primarily as composite particles composed of a heterogeneous mix of all particle sizes. Our findings also support existing literature that turbidity can be a good proxy for elements such as P, which are preferentially adsorbed onto iron oxide coatings thus in situ turbidity probes have great potential to provide relatively inexpensive estimates of P flux when calibrated for specific watersheds.