Shoreline ecosystems

The most numerous organisms living on the seashore are monerans. This group consists of one-celled organisms, both autotrophs and heterotrophs that are extremely simple in structure. All of the monerans play essential roles in shoreline ecosystems. The autotrophic forms are some of the most important intertidal producers, and the heterotrophs are vital to the decomposition processes. 

All species of tide pool fish face unusual environmental conditions and possess special adaptations to help them survive in this unique situation. Like other vertebrates in the ocean, fish are consumers that feed near the top of the food chain and important members of shoreline ecosystems. 

Once the petroleum or solvent is contained, the conventional means of recovery is to recover oil using devices known as skimmers . Skimmers are available in a wide variety of configurations and sizes. They too require extensive manpower to deploy and operate. Often skimmers are unable to recover more than about 10% of the volume of the oil spiU. Often the oil will reach shoreline, from where the oil will be removed if it can cause potential for further water recontamination or damage to the shoreline ecosystem. The cost of shoreline cleanup, the amount of manpower and the time taken to do manual cleanup is often staggering. In the case of the Exxon Valdez spill in 1989, the total cost of cleanup was 2,000,000,000, most of which was shoreline cleanup and secondarily on-water recovery. 

In marine ecosystems, the high copper levels measured in heavily contaminated coastal areas sometimes approach the incipient lethal concentrations for some organisms (Neff and Anderson 1977). Elevated copper concentrations in marine and estuarine environments may result from atmospheric deposition, industrial and municipal wastes, urban runoff, rivers, and shoreline erosion. Chesapeake Bay, for example, receives more than 1800 kg of copper daily from these sources (Hall et al. 1988). Copper concentrations in abiotic marine materials are generally higher near shore than... 

Field Studies. We have attempted to compare the relative availability of actinides to small mammals living in contaminated environments near ORNL. Shrews, rats and mice have been collected from a 30 year old contaminated floodplain forest ecosystem ( ). Cotton rats (Sigmodon hispidus) have been collected from the banks of a former liquid radioactive waste pond which contains Pu, Am and Cu in sediments and shoreline vegetation. Analyses were performed by isotope dilution mass spectrometry (U, Th and Pu) or by alpha spectrometry (Pu, Am and Cm). 

Class Asteroidea, sea stars, is one of the most widely recognized groups of marine organisms due to their prevalence upon the shoreline and their characteristic shape. Asteroids are top predators in benthic ecosystems, often preying upon bivalves from the phylum Mollusca. The isoprenoid compound mytiloxanthin, for example, has been isolated from both the sea star Asterias rubens and the bivalve Mytilus edulis,119 The class Concentricycloidea was first identified in 1986 and consists of two species in the genus Xyloplax. Class Ophiuroidea, brittle stars, contains the greatest number... 

The uses and end points measured for enclosure studies are similar to mesocosms, but here a portion of the natural environment is enclosed and manipulated, rather than constructing an artificial system. Manipulations include adding previously unexposed organisms to an enclosure in a contaminated environment, or applying test chemicals to an enclosed portion of a noncontaminated environment. Terrestrial enclosures are usually corrals fenced in by wire or plastic mesh or impermeable barriers such as metal or plastic sheets. They may range from < 1 m to more than a hectare. Aquatic enclosures may include a section of the shoreline fenced off by plastic curtains (littoral enclosures) or boxes made of flexible plastic sheets suspended in open water (limno-corrals). Small enclosures are used to monitor acute toxicity or sublethal effects, while larger enclosures may study population, community, or ecosystem level end points. 

The shipment of oil by tanker and the recovery of oil from offshore deposits have resulted in many spills in the ocean. The ocean oil spills near shore have ruined beaches, killed birds, and aquatic mammals. The spills poison the shallow ecosystems along the shoreline where many sea creatures breed and their young mature. The EXXON Valdez spill is estimated to have killed 500,000 birds. Virtually everyone agrees that oil spills hear shores are environmental disasters. 

Recovery potential refers to the ability of organisms or ecosystems to return to their original state, or the state they were in before the spill event. Recovery time varies from days to years. For example, the ecosystem of a rocky shoreline can recover from an oil spill within months as organisms from unoiled areas can move in and restore the population. 

The sea includes a wide variety of ecosystems, species, and habitats. When looking at the effects of oil spills, it is convenient to divide these into fish, plankton, benthic invertebrates, epontic organisms, marine mammals, intertidal and shoreline organisms, marine plants, and special ecosystems. 

Tett, P. and Mills, D. (1991) The plankton of the North Sea - pelagic ecosystems under stress Ocean and Shoreline Management, 16, 233-257. 

The dam site and its reservoir, however, do affect the local ecosystem. The land lost to the reservoir through flooding is likely already home to many species of animals and plants and may include towns or villages, all of which will be displaced or destroyed by the dam project. It is possible the reservoir will form a wetlands area at the shoreline. It also is possible that this will not occur, resulting instead in areas of stagnant water that are not hospitable to wildlife. 

---