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Bicknell A.W.J.,University of Plymouth | Bicknell A.W.J.,University of Sheffield | Knight M.E.,University of Plymouth | Bilton D.,University of Plymouth | And 3 more authors.
Molecular Ecology | Year: 2012

Dramatic local population decline brought about by anthropogenic-driven change is an increasingly common threat to biodiversity. Seabird life history traits make them particularly vulnerable to such change; therefore, understanding population connectivity and dispersal dynamics is vital for successful management. Our study used a 357-base pair mitochondrial control region locus sequenced for 103 individuals and 18 nuclear microsatellite loci genotyped for 245 individuals to investigate population structure in the Atlantic and Pacific populations of the pelagic seabird, Leach's storm-petrel Oceanodroma leucorhoa leucorhoa. This species is under intense predation pressure at one regionally important colony on St Kilda, Scotland, where a disparity between population decline and predation rates hints at immigration from other large colonies. amova, FST,φST and Bayesian cluster analyses revealed no genetic structure among Atlantic colonies (Global φST = -0.02 P > 0.05, Global FST = 0.003, P > 0.05, structureK = 1), consistent with either contemporary gene flow or strong historical association within the ocean basin. The Pacific and Atlantic populations are genetically distinct (Global φST = 0.32 P < 0.0001, Global FST = 0.04, P < 0.0001, structureK = 2), but evidence for interocean exchange was found with individual exclusion/assignment and population coalescent analyses. These findings highlight the importance of conserving multiple colonies at a number of different sites and suggest that management of this seabird may be best viewed at an oceanic scale. Moreover, our study provides an illustration of how long-distance movement may ameliorate the potentially deleterious impacts of localized environmental change, although direct measures of dispersal are still required to better understand this process. © 2012 Blackwell Publishing Ltd. Source

Davies J.S.,University of Plymouth | Howell K.L.,University of Plymouth | Stewart H.A.,British Geological Survey | Guinan J.,Marine Institute of Ireland | And 2 more authors.
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2014

In 2007, the upper part of a submarine canyon system located in water depths between 138 and 1165m in the South West (SW) Approaches (North East Atlantic Ocean) was surveyed over a 2 week period. High-resolution multibeam echosounder data covering 1106km2, and 44 ground-truthing video and image transects were acquired to characterise the biological assemblages of the canyons. The SW Approaches is an area of complex terrain, and intensive ground-truthing revealed the canyons to be dominated by soft sediment assemblages. A combination of multivariate analysis of seabed photographs (184-1059m) and visual assessment of video ground-truthing identified 12 megabenthic assemblages (biotopes) at an appropriate scale to act as mapping units. Of these biotopes, 5 adhered to current definitions of habitats of conservation concern, 4 of which were classed as Vulnerable Marine Ecosystems. Some of the biotopes correspond to descriptions of communities from other megahabitat features (for example the continental shelf and seamounts), although it appears that the canyons host modified versions, possibly due to the inferred high rates of sedimentation in the canyons. Other biotopes described appear to be unique to canyon features, particularly the sea pen biotope consisting of Kophobelemnon stelliferum and cerianthids. © 2014 Elsevier Ltd. Source

Bridgewater P.,Joint Nature Conservation Committee
Botanical Journal of the Linnean Society | Year: 2011

Is a target a goal? What is an indicator? Targets, or goals, are the desired outcomes of a policy framework; they show where we want to be and represent the successful implementation of policy. To get there, a mission is needed, but all too often this is confused with targets, goals and vision. Good targets need good indicators to measure success along the way. However, indicators are often left aside from target setting, a self-defeating strategy and one regrettably followed by the Convention on Biological Diversity in 2002 and again in 2010 in setting global targets for reducing the rate of loss of biodiversity. Embracing a highly aspirational target (i.e. reduce the rate of loss of biodiversity by 2010) is easy, but measuring the success of that target is the tricky bit! SMART targets are well known, but CUTE targets (Comprehensive, Understandable, Time-bound and Enabling) can be more effective in public policy setting. Often in public policy, the focus is all on process and outputs, and all too rarely on outcomes. Targets can capitalize on the input from policy, but must be informed by potential indicators from the outset and, in the end, must also enable policy delivery and refreshed outcomes, a critical failing of the 2010 target. © 2011 The Linnean Society of London. Source

Tanentzap A.J.,University of Cambridge | Mountford E.P.,Joint Nature Conservation Committee | Cooke A.S.,Greenlawns | Coomes D.A.,University of Cambridge
Journal of Ecology | Year: 2012

1. Multi-stemmed trees are an understudied but common component of temperate broadleaf forests that can provide insight into how plants persist and regenerate within communities. In particular, multi-stemmed architecture may be an important trait for the growth and survival of trees in forest understoreys that have to cope with low light levels, but this idea has been rarely tested using long-term individual-level data. 2. We use measurements of 8527 individual woody stems from 1985, 1996 and 2008 to model the growth, survival and recruitment of hazel (Corylus avellana) and hawthorn (Crataegus laevigata and C. monogyna) trees as a function of neighbourhood competition in the understorey of a minimum-intervention, mixed-ash woodland in England. We test the effects of browsing by deer (Muntiacus reevesi) on woodland dynamics by comparing demographic rates during a period of high deer densities (1985-1996) with rates recorded from 1996 to 2008, when sustained culling substantially reduced deer densities. 3. Growth and survival of hazel and hawthorn trees increased with the number of stems they possessed, demonstrating clear benefits to multi-stemmed architecture. Surviving trees continued to accumulate basal area and stems without any clear upper limit after 23years. However, increasing numbers of stems generally reduced the growth and recruitment of stems within multi-stemmed trees. 4. Temporal differences in deer browsing appeared to influence the strength of intra-specific (i.e. inter-stem) competition and, consequently, the growth, survival and recruitment of multi-stemmed trees. Most notably, stem survival declined with the number of stems in a tree only after deer culling, but not during a period of high deer densities, suggesting that intense deer browsing reduced resource competition among stems. Inter-specific neighbourhood competition had no detectable effect on hazel or hawthorn demography. 5. Synthesis. Multi-stemmed architecture is an advantageous trait for understorey trees in temperate woodlands relative to the allocation of resources towards the growth of a single stem. We suggest that the low light levels of forest understoreys favour 'persistence', through multi-stemmed growth, rather than 'regeneration' niches (i.e. periodic recruitment through seed), with the advantage of this life-history strategy influenced by herbivory and intra-specific competition. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society. Source

Lascelles B.G.,Global Seabird Programme | Langham G.M.,National Audubon Society | Ronconi R.A.,Dalhousie University | Reid J.B.,Joint Nature Conservation Committee
Biological Conservation | Year: 2012

Marine Protected Areas (MPAs) are recognised as a key component of an ecosystem-based approach to managing the marine environment more effectively and sustainably. Marine top predators, such as seabirds, may be used to identify and prioritize sites for marine conservation. Here we highlight the important role that seabird scientists can play in identifying candidate sites for MPAs; areas identified using at-sea surveys, seabird tracking, and species-habitat modelling. Prioritization of species and sites needs knowledge of ecological and habitat dynamics, threats and important areas at key stages of annual and life-cycle. The results need to be interpreted within the context of relevant policy mechanisms and agreements. The size and shape of candidate MPAs should be: (a) realistic for the key species and systems involved; (b) easy to monitor and enforce; and (c) where feasible involve reasonably long-term data sets. Designation of MPAs by relevant authorities and organisations will require effective advocacy (at local, national and international levels) and must be based on robust and defensible science. Site boundaries should also be sufficient flexibility to be modified, if necessary, in the light of future experience and data collection. The effectiveness of MPAs at the scale required for seabird conservation will need to build on existing experience and develop innovative, as well as traditional, marine spatial planning, monitoring and management techniques. To achieve this within the target timeframes outlined in a number of policy mechanisms will require the rapid development of new approaches, resources and partnerships. © 2012 Elsevier Ltd. Source

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