92 research outputs found

    Morphodynamic Study of a 2018 Mass-Stranding Event at Punta Umbria Beach (Spain): E ect of Atlantic Storm Emma on Benthic Marine Organisms

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    Very few mass stranding events of invertebrates have been reported. In this paper, we report a mass stranding of multiple benthic organisms occurred at Punta UmbrĂ­a beach (S Spain) after the passage of storm Emma (28 February to 5 March 2018). The most abundant organisms were identified, and exceptional meteorological and oceanographic events were analyzed, as a basis to understand the causes of stranding. The morphodynamic changes a ecting the beach profile during the storm were inferred using a cross shore depth-integrated and time averaged numerical model (CSHORE). Among the stranded species, decapods (Upogebia spp., Atelecyclus undecimdentatus), sipunculids (Sipunculus nudus), starfish (Astropecten sp.), and sessile tunicates were dominant. Storm Emma involved extreme significant wave heights of up to 7.27 m, low pressures, strong SW winds, precipitations and spring tides that modified the seabed elevation to depth as deep as 10 m. Simulations suggest that benthic organisms living at a water depth between 10 to 0.3 m were buried under a layer of sediment of up to ca. 10 cm deposited during the storm. This burial preceded the transport of intertidal and subtidal benthic organisms to the dry beach, causing their stranding. Impacts on the quality of habitat, biodiversity and the productivity of coastal ecosystems are discussed

    Fish taphonomy and environmental inference in paleolimnology

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    The contribution of fish studies to palaeoecology generally takes the form of (1) inference from analogies in modern fish faunas and (2) fish taphonomy--the pattern of death and dispersal of bones. (1) Modern fish faunas and associated organisms provide taxonomic, ecological, or functional analogues for interpretation of ancient limiting factors and behaviors. These inferences presume taxonomic conservatism. They also presume functional relationships between morphological form and feeding mode or habitat. They become weak with increased geologic age or phyletic distance between ancient subject and modern anaogue. (2) Fish taphonomy may contribute information about limnology, community composition, life history, mortality, depositional environment, and preservation. Taphonomic reconstruction of ecology and preservation depends on the applicability of analogous processes in modern ecology and l limnology.In aquatic taphonomy, temperature is the most important factor in determining the fate of a carcass. Above about 16[deg]C (depending on depth and pressure), most carcasses are made buoyant by bacterial decay gases and are transported to the surface where they may decay further and fall piecemeal into deepwater environments, or drift to beach environments where wave energy disarticulates, abrades, and scatters the bones. Below about 16[deg]C, most carcasses remain on the bottom until buried; they may be disturbed by scavengers, depending on oxygen concentration in the hypolimnion.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27579/1/0000623.pd

    Cascaded logic gates in nanophotonic plasmon networks

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    Optical computing has been pursued for decades as a potential strategy for advancing beyond the fundamental performance limitations of semiconductor-based electronic devices, but feasible on-chip integrated logic units and cascade devices have not been reported. Here we demonstrate that a plasmonic binary NOR gate, a 'universal logic gate', can be realized through cascaded OR and NOT gates in four-terminal plasmonic nanowire networks. This finding provides a path for the development of novel nanophotonic on-chip processor architectures for future optical computing technologies

    Largest baleen whale mass mortality during strong El Nino event is likely related to harmful toxic algal bloom

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    While large mass mortality events (MMEs) are well known for toothed whales, they have been rare in baleen whales due to their less gregarious behavior. Although in most cases the cause of mortality has not been conclusively identified, some baleen whale mortality events have been linked to bio-oceanographic conditions, such as harmful algal blooms (HABs). In Southern Chile, HABs can be triggered by the ocean-atmosphere phenomenon El Nino. The frequency of the strongest El Nino events is increasing due to climate change. In March 2015, by far the largest reported mass mortality of baleen whales took place in a gulf in Southern Chile. Here, we show that the synchronous death of at least 343, primarily sei whales can be attributed to HABs during a building El Nino. Although considered an oceanic species, the sei whales died while feeding near to shore in previously unknown large aggregations. This provides evidence of new feeding grounds for the species. The combination of older and newer remains of whales in the same area indicate that MMEs have occurred more than once in recent years. Large HABs and reports of marine mammal MMEs along the Northeast Pacific coast may indicate similar processes in both hemispheres. Increasing MMEs through HABs may become a serious concern in the conservation of endangered whale species

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