218,411 research outputs found
Depoe Bay Notice of Adopted Amendment (2010-05-11)
No full text8 pp. Adopted 2010-05-11. Department of Land Conservation and Development Notice of Adopted AmendmentAmendments to the Depoe Bay Zoning Ordinance: A. Revisions to ORS references B. Fractional Ownership definition C. Manufactured Home added as permitted use in the R-l zone; Manufactured Dwelling changed to Manufactured Home in the R-2, R-3, R-4, and R-5 zones D. Revision to Coastal Shoreland review procedure E. Revision to survey requirements F. Notice of public hearing revision G. Add description of quasi-judicial continuances and time limits H. Add time limits on geologic hazards permits I. Description of public street maintenance responsibilities J. Deletion of performance agreement option K. Editorial change to reference appropriate sections in the Land Division ordinanc
Little Bay Islands : past, present and future, an historical review
No full textLittle Bay Islands U.C. School Magazine 1942A brief geographical description of our island / Bob Forward -- A brief history of settlement and people of Little Bay islands / H. T. Burden -- The church / Gwen Jones -- Societies / Jennette Locke -- Education and schools / Marion Wiseman -- Trade / Bill Hyde -- Industries / Norman Wiseman -- Miscellaneous / H. T. Burden -- Little Bay Islands' part in two world wars / Garland Wiseman -- Little Bay Islands at present ; its people, etc. / Dorothy Wiseman -- The future / Rev. R. N. RowsellAt head of title: Little Bay Islands U.C. School Magazine, 194
Seagrasses of Moreton Bay Quandamooka: Diversity, ecology and resilience
No full textSeagrasses are a dominant feature in the seascape of Moreton Bay. They host numerous animals and provide the region with a wide range of ecosystem services that we are only beginning to better understand. In the past 20 years, the focus of seagrass research in Moreton Bay has shifted towards predictive modelling based on comprehensive ecological understanding. There are seven species of seagrasses in Moreton Bay that persist across a wide range of environmental conditions from muddy sediments in the western Bay to the cleaner, sandier waters of the eastern Bay adjacent to Moreton (Moorgumpin) and Stradbroke (Minjerribah) Islands. There has been an encouraging recovery of meadows in some of the more degraded parts parts of the Bay, yet with an ever-increasing human population in South East Queensland, the threats to seagrasses still require continued research effort and careful management. This paper reviews the current understanding of Moreton Bay’s seagrass meadows and provides recommendations for future research.Full Tex
Fishes of Moreton Bay: Ecology, human impacts, and conservation
No full textMoreton Bay is a heterogeneous seascape containing a mosaic of habitats that support a diversity of fish. The fish fauna includes many species that are harvested by recreational and commercial fishers as well as numerous taxa that are of conservation concern. The fish fauna of mangroves, seagrasses, inshore reefs and intertidal flats is well sampled. By contrast, fish surveys in saltmarshes, soft sediments, offshore reefs and surf zones are sparse and incomplete. Fish diversity and abundance are typically highest on reefs and seagrass meadows, but most species move among habitats to feed and spawn. These movements connect habitats and link both fish assemblages and food webs across seascapes. The combined effects of water quality, coastal urbanisation and fishing also shape fish assemblages in Moreton Bay. Fish diversity and abundance increases from the urbanised western to the less developed eastern Bay. This spatial pattern mirrors gradients in water quality and habitat condition across the Bay. The shorelines of many estuaries and ocean beaches have been developed, and this coastal urbanisation has altered fish diversity, abundance and diet. Numerous species have, however, adapted to capitalise on the abundance of food and shelter in urban estuaries. No-take marine reserves prohibit fishing, and this promotes fish abundance and diversity in some ecosystems (e.g. coral reefs, seagrass meadows), but not in others (e.g. estuaries, ocean beaches). Important challenges for future research in Moreton Bay include: (i) testing how multiple human pressures combine to modify fish assemblages and fish habitats; (ii) identifying how the ecological attributes of ecosystems and seascapes shape conservation outcomes; and (iii) examining how fish assemblages, habitats and fisheries change in response to range shifts of tropical species that move south with rising sea temperatures.Full Tex
Soundings: the Newsletter of the Monterey Bay Chapter of the American Cetacean Society. 2013
No full textIssues January - November/December 2013. (PDF contains 96 pages
The Amplification of Tsunamis by Mercury Bay, New Zealand
No full textThe east coast of New Zealand is exposed to tsunami hazards, which are generated by both distant and near tsunamigenic sources. The impact of tsunami varies along the coast depending on the source region and the amount of local attenuation or amplification. Some regions have consistently amplified historic tsunami, including Mercury Bay on the east coast of the Coromandel Peninsula. Whitianga, located in the Mercury Bay, is now the fastest growing population centre in the Coromandel Region; hence, tsunami hazard is of particular concern. The natural resonance periods (eigen periods) of Mercury Bay are determined by its geometry and depth, and tsunami waves that enter the Bay will be amplified when their frequencies match the resonant frequencies of the Bay. The combination of tide levels with the amplified tsunami waves may lead to a destruction of the moored vessels and many coastal facilities. To date, amplification within the bay has mostly increased the trough depth, while having little effect on the crest height.
This study assesses the tsunami hazard in Mercury Bay in response to a tsunami generated along the Kermadec subduction margin (Kermadec Trench). Even though historically, the Kermadec Trench has never produced a hazardous tsunami affecting the eastern coast of New Zealand, it is still important to develop an assessment of the worst scenarios of earthquake generated tsunamis from this source. In particular, the Sumatra 2004 and Tohuku 2011 tsunami events have suggested that a magnitude Mw 9 to 9.5 subduction megathrust earthquake is a plausible scenario.
Merian’s formula was used to obtain the natural resonant period of Mercury Bay and 17 scenarios of tsunamigenic earthquakes were simulated using the tsunami model COMCOT version 1.7. Those scenarios included the recent various combination of the Kermadec earthquake, and hypothetical earthquakes that rupture the northern, middle, southern parts of Kermadec Trench. The results demonstrate that most of the initial tsunami waves generated by Kermadec Trench earthquakes are negative waves that arrive in the Bay within 56 to 158 minutes of the earthquake. This may explain the observed historical pattern of enhanced amplification of the troughs. However, significant amplification of the crests, producing waves that would threaten Whitianga Township, are generated by Kermadec earthquakes with magnitudes greater than Mw 8.5.
From the spectral analysis of each tsunami model, Mercury Bay showed a consistent response of about 52 minutes dominant period. This period is also shown as the period of the Mercury Bay when tsunami is absent. In response to distant tsunamis, it seems that the geometry of the Mercury Bay control their periods as they enter the bay. Both the 2011 Tohoku and 2010 Chilean Events have the dominant periods close to the Mercury Bay period at 47 and 51 minutes respectively
Marine reservoir corrections for Moreton Bay, Australia
No full textWe present the first direct assessment of marine reservoir effects in the Moreton Bay region using radiocarbon dating of known-age, pre-AD 1950, shell samples from the east coast of Stradbroke Island and archaeological shell/charcoal pairs from Peel Island in Moreton Bay. The resulting ΔR value of 9±19 14C years for the open ocean conforms to regional values established for northeast Australia of 12±10 14C years. Negative ΔR values of -65±61 14C years and -216±94 14C years for southern Moreton Bay highlight the potential for larger offsets over the last ~900 years. These may be linked to changing terrestrial inputs and local circulation pattern
A Spatial Study of Benthic Microalgae in an Intertidal Sandflat at East Beach in Galveston Bay, Texas
No full textpg. 211A substantial portion of Galveston Bay is intertidal sand and mudflats. Therefore, the purpose of this study is to examine the spatial scale of benthic microalgal biomass and diversity in a typical intertidal habitat for Galveston Bay. These results will provide insights into spatial linkages between benthic microalgal biomass and consumers. The interactions of the main environmental structuring factors; light, nutrients and grazing can cause the community structure to vary temporally and spatially. By understanding how sediment microbial systems are structured, we can then understand how benthic microalgae impact higher trophic levels
The geological evolution and sedimentary dynamics of Hout Bay, South Africa
No full textIncludes bibliographical references.Hout Bay is situated on the Atlantic seaboard of the Cape Peninsula, in the Western Cape Province of South Africa approximately 17 km southwest of Cape Town. Hout Bay is a southward opening bay that hosts a fishing harbour and coastal residential town. This study was initiated to map the marine geology of Hout Bay and to quantify and explain the sediment dynamics of the area. This is important as Hout Bay has the only substantial accumulation of Quaternary sediments on the Atlantic Seaboard of the Cape Peninsula. The Hout Bay study area was saturated with the latest in cutting-edge geophysical techniques to collect detailed and comprehensive bathymetric, sidescan sonar, magnetic, seismic and beach profiling data. Collectively these data can be used to map offshore geological units as well as infer how Hout Bay has responded to the varying changes in sea-level throughout the Quaternary and allow for the reconstruction of the geological evolution of the Hout Bay seafloor
Do plants really reduce salt marsh erosion in Galveston Bay
No full text[np]The results of this study challenge our conception of the traditional paradigm that plant roots directly prevent erosion along the coast. Previous studies have focused solely upon the ability of above-ground plant stems and leaves to reduce wave forces in the water column, yet these studies have ignored the physical mechanism that results in the majority of salt marsh erosion in Galveston Bay- undercutting of the marsh edge by waves. To investigate marsh edge erosion, we placed extracted marsh cores into a wave flume and sent waves at them. The waves simulated a typical windy 24 hour period in Galveston Bay. We tested for differences in erosion rates between cores with plants and without plants, for differences among plant species, and for differences in soil types. The results showed that the soil type was the master variable that determined the erosion rate, rather than the plants. In particular, bulk density and sediment particle size provided the best predictors for erosion rate. The presence of plants or live plant roots made no significant difference upon the erosion rate. Rather than the living plants and roots, we suggest that it is the indirect input of plant detritus in the form of finely-grained organic particles that lends cohesiveness to the soil, along with the associated changes in bulk density and particle size. As plant-produced detritus becomes incorporated into the matrix, the soil becomes less dense, finer, and more resistant to erosion. Thus, plants do not directly reduce erosion, but do so indirectly through modification of the soil parameters. Of all the extracted cores that we tested, the dense, coarse, inorganic, and sandy sediment from the terraces at Galveston Island State Park (a restored salt marsh) eroded the quickest. This study is important because it suggests that salt marsh restoration efforts should place the highest priority upon getting the soil right
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