12 research outputs found

    Climate drives the geography of marine consumption by changing predator communities

    Get PDF
    Este artículo contiene 7 páginas, 3 figuras, 1 tabla.The global distribution of primary production and consumption by humans (fisheries) is well-documented, but we have no map linking the central ecological process of consumption within food webs to temperature and other ecological drivers. Using standardized assays that span 105° of latitude on four continents, we show that rates of bait consumption by generalist predators in shallow marine ecosystems are tightly linked to both temperature and the composition of consumer assemblages. Unexpectedly, rates of consumption peaked at midlatitudes (25 to 35°) in both Northern and Southern Hemispheres across both seagrass and unvegetated sediment habitats. This pattern contrasts with terrestrial systems, where biotic interactions reportedly weaken away from the equator, but it parallels an emerging pattern of a subtropical peak in marine biodiversity. The higher consumption at midlatitudes was closely related to the type of consumers present, which explained rates of consumption better than consumer density, biomass, species diversity, or habitat. Indeed, the apparent effect of temperature on consumption was mostly driven by temperature-associated turnover in consumer community composition. Our findings reinforce the key influence of climate warming on altered species composition and highlight its implications for the functioning of Earth’s ecosystems.We acknowledge funding from the Smithsonian Institution and the Tula Foundation.Peer reviewe

    Mantid expansion into North American salt marshes

    No full text
    International audienceMantids are influential generalist predators in terrestrial systems. Therefore, large mantid species like the European mantid, Mantis religiosa (Linnaeus, 1758), are often used by humans and purposefully introduced as a form of biocontrol, greatly expanding their geographic ranges. However, mantids are rarely recorded in marine systems. In this study, we present an observation of European mantids living in a salt marsh and actively moulting in the vegetation in Elkhorn Slough, in Monterey Bay, California, United States of America. Not only are these European mantids a nonnative species, but every observed individual was a flightless juvenile, meaning they hatched nearby. Although mantids are not usually associated with intertidal ecosystems, there are multiple potential reasons that mantids would be drawn to salt marshes, including food, potential for camouflage, and lower predation pressure. The addition of a generalist predator could produce a complex mix of positive and negative impacts on the marsh itself and, given the importance of marsh systems, these possible effects warrant further study

    Data from: Fat, fibre and cancer risk in African Americans and rural Africans

    No full text
    Rates of colon cancer are much higher in African Americans (65:100,000) than in rural South Africans (<5:100,000). The higher rates are associated with higher animal protein and fat, and lower fibre consumption, higher colonic secondary bile acids, lower colonic short-chain fatty acid quantities and higher mucosal proliferative biomarkers of cancer risk in otherwise healthy middle-aged volunteers. Here we investigate further the role of fat and fibre in this association. We performed 2-week food exchanges in subjects from the same populations, where African Americans were fed a high-fibre, low-fat African-style diet and rural Africans a high-fat, low-fibre western-style diet, under close supervision. In comparison with their usual diets, the food changes resulted in remarkable reciprocal changes in mucosal biomarkers of cancer risk and in aspects of the microbiota and metabolome known to affect cancer risk, best illustrated by increased saccharolytic fermentation and butyrogenesis, and suppressed secondary bile acid synthesis in the African Americans

    Metadata

    No full text
    CSV file containing the sample metadata in the HITChip data matrix. The variables are rounded or aggregated to ensure subject anonymity. 'NA' refers to missing values. The variable units and other information are as follows: - SampleID: unique sample identified corresponding to samples in the HITChip data matrix - subject: Subject identifier (some subjects have multiple time points) - bmi: Standard body-mass classification (underweight: 45). - sex (male/female) - nationality: African American (AAM); Native African (AFR) - timepoint.group: Time point (1/2) within the group (ED/HE/DI) - timepoint.total: Time point in the overall data set (ED1 - HE1 -HE2 - DI1 - DI2 - ED2 ie. 1- 2- 3- 4- 5- 6) - group: Sample treatment group: as described in the main article; Dietary intervention (DI) / Home environment (HE) / Solid stool pre-colonoscopy (ED
    corecore