26 resultados para shore birds


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Intertidal macrobenthic faunal assemblages of a dual seagrass/callianassid-structured sandflat system were investigated in subtropical Moreton Bay, Queensland. Consistently across all 20 stations, the gastropod-dominated seagrass supported greater abundance (2.5×) and species richness (2×) than the amphipod-dominated sandflat. There was no evidence of along-shore or up-shore variation in the overall assemblage properties such as total abundance, species richness or diversity within either habitat type, except for variation in sandflat abundance between sites. But seagrass and sandflat assemblages both varied significantly in composition from site to site, and seagrass assemblage composition also varied with shore height. Shore height and site, however, only accounted for ≤41% of total variation. The two faunal assemblages showed a Bray–Curtis dissimilarity of 97.7% and within-habitat similarities of <20%. There was no consistency in distribution of greater diversity, dominance or evenness. No differential between any assemblage features in adjacent sandflat and seagrass samples changed with shore height, supporting hypotheses that such differentials are not maintained by predation. Macrofaunal species richness and diversity were closely coupled within sandflat stations but were uncoupled within seagrass ones, questioning the value of diversity as a comparative measure.

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Commercial capture fisheries produce huge quantities of offal, as well as undersized and unwanted catch in the form of discards. Declines in global catches and legislation to ban discarding will significantly reduce discards, but this subsidy supports a large scavenger community. Understanding the potential impact of declining discards for scavengers should feature in an eco-system based approach to fisheries management, but requires greater knowledge of scavenger/fishery interactions. Here we use bird-borne cameras, in tandem with GPS loggers, to provide a unique view of seabird/fishery interactions. 20,643 digital images (one min 21) from ten bird-borne cameras deployed on central place northern gannets Morus bassanus revealed that all birds photographed fishing vessels. These were large (>15 m) boats, with no small-scale vessels. Virtually all vessels were trawlers, and gannets were almost always accompanied by other scavenging birds. All individuals exhibited an Area-Restricted Search (ARS) during foraging, but only 42% of ARS were associated with fishing vessels, indicating much 'natural' foraging. The proportion of ARS behaviours associated with fishing boats were higher for males (81%) than females (30%), although the reasons for this are currently unclear. Our study illustrates that fisheries form a very important component of the prey-landscape for foraging gannets and that a discard ban, such as that proposed under reforms of the EU Common Fisheries Policy, may have a significant impact on gannet behaviour, particularly males. However, a continued reliance on 'natural' foraging suggests the ability to switch away from scavenging, but only if there is sufficient food to meet their needs in the absence of a discard subsidy.

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The present contribution reports on the capture of two adult male specimens of the Asian/Japanese shore crab, Hemigrapsus sanguineus (de Haan, 1835) from Glamorgan, south Wales and Kent, southern England. These represent the first records of this species from mainland Great Britain.

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Coastal processes and wildlife shape the coast into a variety of eye-catching and enticing landforms that attract people to marvel at, relax and enjoy coastal geomorphology. These landforms also influence biological communities by providing habitat and refuge. There are very few field guides to explain these processes to the general public and children. In contrast, there is a relative wealth of resources and organised activities introducing people to coastal wildlife, especially on rocky shores. These biological resources typically focus on the biology and climatic controls on their distribution, rather than how the biology interacts with its physical habitat. As an outcome of two recent rock coast biogeomorphology projects (detailed at: www.biogeomorph.org/coastal) a multi disciplinary team produced the first known guide to understanding how biogeomorphological processes help create coastal landforms. The ‘Shore Shapers’ guide (shoreshapers.org) is designed to: a. bring biotic geomorphic interactions (how animals, algae and microorganisms protect and shape rock) to life and b. introduce some of the geomorphological and geological controls on biogeomorphic processes and landform development. The guide provides scientific information in an accessible and interactive way – to help sustain children’s interest and extend their learning. We tested a draft version of the guide with children,the general public and volunteers on rocky shore rambles using social science techniques and present the findings, alongside initial results of an evaluation of a newer version of the guide and interactive workshops taking place throughout 2014.