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Migration Delays at Head-of-Tide Weirs are a Function of Tidal Cycles and River Flows in Anadromous Twaite Shad Alosa fallaxNARA Subscribed
Riverine barriers can have significant negative impacts on the spawning migrations of anadromous fishes, with barriers of low passage efficiency limiting access to upstream spawning areas. Even fish that pass a barrier can be negatively affected via migration delays and energetic costs. The spawning migrations of 74 twaite shad Alosa fallax were tracked at two head-of-tide weirs on a bifurcated channel in the River Severn’s up...
Emigration of post‐spawned twaite shad Alosa fallax , an anadromous and iteroparous fish, in a highly fragmented riverNARA Subscribed
Anthropogenic barriers are widely known to negatively impact the spawning migrations of anadromous fishes, by delaying or preventing passage upstream. Although the impacts of barriers on emigrating post‐spawned adults are less well studied, they could potentially impact the fitness and subsequent return rates of iteroparous species. In this study, passive acoustic telemetry was used to track the emigrations of 53 twaite shad A...
The timing of entry into freshwater by mature anadromous fishes is an important component of their migration phenology. In iteroparous anadromous species, identifying the migration cues that influence the timing of entry into freshwater, and annual variability in these timings, is important in assessing the extent of individual repeatability. Here, passive acoustic telemetry tracked 71 twaite shad Alosa fallax (‘shad’) returni...
Intercontinental analysis of temperate steppe stream food webs reveals consistent autochthonous support of fishesNARA Subscribed
Quantifying the trophic basis of production for freshwater metazoa at broad spatial scales is key to understanding ecosystem function and has been a research priority for decades. However, previous lotic food web studies have been limited by geographic coverage or methodological constraints. We used compound‐specific stable carbon isotope analysis of amino acids (AAs) to estimate basal resource contributions to fish consumers...
Delineation of blacktip shark ( Carcharhinus limbatus ) nursery habitats in the north‐western Gulf of MexicoNARA Subscribed
Coevolution with predators leads to the use of low‐risk habitats by many prey species, which promotes survival during early developmental phases. These nurseries are valued by conservation and management agencies because of their contributions to adult populations. However, the physical and geographic characteristics, like shallow depths and isolation from other marine habitats, that restrict access to predators and thereby re...
Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and without prior cardiovascular events, dementia or persistent physical disability. Disab...
Catch-and-release angling is widespread, but the impacts of this practice for captured individuals are understudied, especially among elasmobranchs. Studies on sub-lethal behavioural impacts are particularly sparse, despite their importance for the interpretation of biologging data and for assessments of species’ tolerance to capture. In this study, the behavioural responses of flapper skate ( Dipturus intermedius ) to catch-a...
Environmental cycles and individual variation in the vertical movements of a benthic elasmobranchNARA Subscribed
Trends in depth and vertical activity reflect the behaviour, habitat use and habitat preferences of marine organisms. However, among elasmobranchs, research has focused heavily on pelagic sharks, while the vertical movements of benthic elasmobranchs, such as skate (Rajidae), remain understudied. In this study, the vertical movements of the Critically Endangered flapper skate ( Dipturus intermedius ) were investigated using arc...
Seasonal and ontogenetic variations in depth use by benthic species are often concomitant with changes in their spatial distribution. This has implications for the efficacy of spatial conservation measures such as marine protected areas (MPAs). The critically endangered flapper skate ( Dipturus intermedius ) is the designation feature of an MPA in Scotland. This species is generally associated with deeper waters >100 m; howeve...
Small global positioning system (GPS) trackers are now routinely used to study the movement and behaviour of birds at sea. If the birds rest on the water they become “drifters of opportunity” and can be used to give information about surface currents. In this paper, we use a small data set from satellite-tracked razorbills (Alca torda) in the Irish Sea to test the potential of this idea for measuring tidal currents. Razorbills...
Global synthesis of the temperature sensitivity of leaf litter breakdown in streams and riversNARA Subscribed
Streams and rivers are important conduits of terrestrially derived carbon (C) to atmospheric and marine reservoirs. Leaf litter breakdown rates are expected to increase as water temperatures rise in response to climate change. The magnitude of increase in breakdown rates is uncertain, given differences in litter quality and microbial and detritivore community responses to temperature, factors that can influence the apparent te...