Effect of sea water level rise on sandy beach profile

Study of batch profile evolution and scouring effect due to the wave and current impacts in the coastal zone has been one of the most important issues in coastal engineering research projects during the past decades .to construct the coastal protective structures such piers, breakwaters and seawalls, it is necessary to estimate the scouring depth and bed level changes in the vicinity of such structures. Furthermore, the time - dependent changes in the equilibrium profile of the surf zone can be of great importance in designing coastal structures. Because of the importance of coastal engineering study in Iran due to the existence of two important coastal area located in the north and south parts of the country, and due to the lack of classified data in this respect (particularly the effect of sea level rise on coastal morphology) in the present study, based on the available data of Bandar Anzali region, an analysis of the coastal zone behavior is made. Bed level elevations are measured and compared with the theoretical equilibrium profile. It is shown that the behavior of the coastal zone in the region is consistent with the dean (equilibrium profile . In the next stage, following extensive investigations, the bed level changes due to a rise in sea level at different locations in the surf zone are estimated. Finally based on the results obtained for profile evolution due to sea level rise, the conclusion is made for design of coastal structures located in the study area. The results obtained from the present study indicate that the sea level rise can have a significant effect on beach profile and resulting erosion in the study area. The results are graphically presented with can be used for design purposes and establishing a data base for the coastal zone in the study region. It is believed that the present work can be regarded as a contribution to the existing knowledge of coast process in the study area and referred to as a basis for the future coastal research projects.

Shoreline erosion due to extreme storms and sea level rise

A summary is presented of research conducted on beach erosion associated with extreme storms and sea level rise. These results were developed by the author and graduate students under sponsorship of the University of Delaware Sea Grant Program. Various shoreline response problems of engineering interest are examined. The basis for the approach is a monotonic equilibrium profile of the form h = Ax2 /3 in which h is water depth at a distance x from the shoreline and A is a scale parameter depending primarily on sediment characteristics and secondarily on wave characteristics. This form is shown to be consistent with uniform wave energy dissipation per unit volume. The dependency of A on sediment size is quantified through laboratory and field data. Quasi-static beach response is examined to represent the effect of sea level rise. Cases considered include natural and seawalled profiles. To represent response to storms of realistic durations, a model is proposed in which the offshore transport is proportional to the "excess" energy dissipation per unit volume. The single rate constant in this model was evaluated based on large scale wave tank tests and confirmed with Hurricane Eloise pre- and post-storm surveys. It is shown that most hurricanes only cause 10% to 25% of the erosion potential associated with the peak storm tide and wave conditions. Additional applications include profile response employing a fairly realistic breaking model in which longshore bars are formed and long-term (500 years) Monte Carlo simulation including the contributions due to sea level rise and random storm occurrences. (PDF has 67 pages.)

Sea-level rise in Hawaii: Implications for future shoreline locations and Hawaii coastal management

Management of coastal development in Hawaii is based on the location of the certified shoreline, which is representative of the upper limit of marine inundation within the last several years. Though the certified shoreline location is significantly more variable than long-term erosion indicators, its migration will still follow the coastline's general trend. The long-term migration of Hawaii’s coasts will be significantly controlled by rising sea level. However, land use decisions adjacent to the shoreline and the shape and nature of the nearshore environment are also important controls to coastal migration. Though each of the islands has experienced local sea-level rise over the course of the last century, there are still locations across the islands of Kauai, Oahu, and Maui, which show long- term accretion or anomalously high erosion rates relative to their regions. As a result, engineering rules of thumb such as the Brunn rule do not always predict coastal migration and beach profile equilibrium in Hawaii. With coastlines facing all points of the compass rose, anthropogenic alteration of the coasts, complex coastal environments such as coral reefs, and the limited capacity to predict coastal change, Hawaii will require a more robust suite of proactive coastal management policies to weather future changes to its coastline. Continuing to use the current certified shoreline, adopting more stringent coastal setback rules similar to Kauai County, adding realistic sea-level rise components for all types of coastal planning, and developing regional beach management plans are some of the recommended adaptation strategies for Hawaii. (PDF contains 4 pages)

How do we raise the profile of ponds?

This article arises from the 1998 Ponds Conference organised by Pond Action. A workshop entitled "How do we raise the profile of ponds?" was held on the first evening of the conference, taking the form of three syndicate groups each tackling one of the following three issues: How to get volunteers and the community involved with ponds; raising the profile of ponds within the government sector; and raising the profile of ponds with scientists. It is clear that, as scientists, our understanding of ponds is not great. However, some progress has been made in understanding the rare species that are likely to occur in them. A great deal more scientific research is required to understand the nature, diversity, distribution, formative processes and wise management options for ponds. However, perhaps of equal or even greater importance is the need for scientists and pond managers to understand the broader values that people across society hold about ponds.

Profile soundings in lakes of the younger morainal area of Sleswick-Holstein with a sediment-echo-sounder of 30 kHz [Translation from: Wass.Boden 26, 135-138, 1974]

To be able to carry out physical, chemical and biological investigations on a lake, one needs a thorough knowledge of the volume of water and the shape of the lake basin. Little is known about the about the morphology of the lakes in Schleswig-Holstein and its ecological consequences. For this research a 30 KHz echo sounder with sediment transceiver was used to carry out profile determinations (echo soundings). This apparatus continuously records on paper the different reflexions and absorptions of the sediment and water body in the corresponding depth. By this, acoustically noticeable layers and different densities in the sediment and 'scattering layers' in the water body due to physical, chemical and biological reasons (e.g. plans and single fish) are made visible. Result are summarised here regarding the echo soundings in Blunker See.

Linefish resources annual report for the year 2000. Part 2: species profile

This work refers to the same biological aspects of Chrysoblephus puniceus (marreco), Polysteganus coeruleopunctatus (cachucho) and Cheimerus nufar (robalo). It shows the progress in the biological study of the three species, pointing out at the same time the few discrepancies, which still need to be resolved.

Changes in body composition and fatty acid profile during embryogenesis of quillback rockfish (Sebastes maliger)

We investigated developmental changes in the body compositions and fatty acid (FA) profiles of embryos and preparturition larvae of the quillback rockfish (Sebastes maliger). Comparisons of proximate composition data from early-stage embryos with data from hatched preparturition larvae taken from wild-caught gravid females indicated that embryos gain over one-third their weight in moisture while consuming 20% of their dry tissue mass for energy as they develop into larvae. Lipid contributed 60% of the energy consumed and was depleted more rapidly than protein, indicating a protein-sparing effect. Oil globule volume was strongly correlated with lipid levels, affirming its utility as an indicator of energetic status. FA profiles of early embryos differed significantly from those of hatched larvae. Differences in the relative abundances of FAs between early embryos and hatched larvae indicated different FA depletion rates during embryonic development. We conclude that some metabolically important FAs may prove useful in assessing the condition of embryos and preparturition larvae, particularly 20:4n-6, which cannot be synthesized by many marine fish and which is conserved during embryogenesis. Variability in body composition and energy use among rockfish species should be considered when interpreting any measures of condition.

The ecology of Atlantic white cedar wetlands: a community profile

This monograph on the ecology of Atlantic white cedar wetlands is one of a series of U.S. Fish and Wildlife Service profiles of important freshwater wetland ecosystems of the United States. The purpose of the profile is to describe the extent, components, functioning, history, and treatment of these wetlands. It is intended to provide a useful reference to relevant scientific information and a synthesis of the available literature. The world range of Atlantic white cedar (Chamaecyparis thyoides) is limited to a ribbon of freshwater wetlands within 200 km of the Atlantic and Gulf coasts of the United States, extending from mid-Maine to mid-Florida and Mississippi. Often in inaccessible sites and difficult to traverse, cedar wetlands contain distinctive suites of plant species. Highly valued as commercial timber since the early days of European colonization of the continent, the cedar and its habitat are rapidly disappearing. This profile describes the Atlantic white cedar and the bogs and swamps it dominates or codominates throughout its range, discussing interrelationships with other habitats, putative origins and migration patterns, substrate biogeochemistry, associated plant and animal species (with attention to those that are rare, endangered, or threatened regionally or nationally), and impacts of both natural and anthropogenic disturbance. Research needs for each area are outlined. Chapters are devoted to the practices and problems of harvest and management, and to an examination of a large preserve recently acquired by the USFWS, the Alligator River National Wildlife Refuge in North Carolina.

FishBase species profile: Clarias gariepinus (Burchell, 1822) North African catfish

In this issue NAGA introduces a new page on profiles of fish species. This page will be a permanent feature of the NAGA and will be based on information derived from FishBase (http://www.fishbase.org), the world’s premier information system on fishes and a global public good. FishBase is being developed by the WorldFish Center and an International Consortium. The first species selected is the North African catfish Clarias gariepinus, one of the most important freshwater fish species in Africa. It has been chosen in honor of Prof Dr Guy Teugels of the Musée Royal de l’Afrique Centrale (MRAC) of Tervuren, Belgium, who recently passed away and who spent many years investigating this species.

A Demographic Profile of Participants in Two Gulf of Mexico Inshore Shrimp Fisheries and Their Response to the Texas Closure

A social study of the shrimp fisheries of Galveston Bay, Tex., and Calcasieu Lake, La., was made during the summer of 1987 to examine the impacts of the seasonal closure of the Federal waters off Texas and to understand the infrastructure and demographic processes of these two diverse fisheries. Survey instruments were administered to 159 shrimp boat captains: 89 from Galveston Bay and 70 from Calcasieu Lake. Shrimp-house owners were interviewed in each region as well. The results suggest that the inshore fisheries (i.e., shrimpers and shrimp houses) are distinct from the offshore fisheries. The infrastructure of the two inshore fisheries examined differ in that the market distribution of shrimp from Galveston Bay was more diffuse than from Calcasieu Lake. Much more of the shrimp harvested from Galveston Bay was channelled into the surrounding community than from Calcasieu Lake. The distribution of age,years as a commercial fisherman, and family involvement in fishing suggest that participation in Calcasieu Lake's and Galveston Bay's inshore fisheries have expanded concurrent with declining economies. While overall the Texas closure had little impact on either of the inshore fisheries, the Galveston Bay shrimpers experienced more of a direct impact on their livelihood than Calcasieu Lake shrimpers.