borers. In such areas, pilings will not 

 have to be replaced as frequently as in 

 non polluted areas. Fluctuating quanti- 

 ties of fresh water in an estuary can 

 also affect populations. If the salinity 

 decreases sufficiently, borer populations 

 will decrease. Physical factors may also 

 have an effect on population density. 

 A pile subject to high wave action will 

 not support the population of gribbles 

 that a pile in quiet waters will support 

 (Hochman 1967). Constant high salinity 

 and tropical temperatures accelerate the 

 decomposition of chemicals used in creo- 

 sote treatment (Lindgren 1974); there- 

 fore, piling in such areas are more sus- 

 ceptible to attack. 



BUOYS AND FLOATING PLATFORMS 



Definitions 



A buoy is an anchored or moored 

 floating object intended as an aid to 

 navigation, for attachment of vessels or 

 instrumentation, or to mark the position 

 of something underwater. If the buoy 

 is to be used primarily for mooring ves- 

 sels, it is called a mooring or anchor 

 buoy. 



A platform is a horizontal flat sur- 

 face usually higher than the adjoining 

 area. A floating platform is a structure 

 that floats on water and is held in place 

 by anchors or piles or other mooring 

 devices. A series of platforms in a line 

 extending from the shoreline to deeper 

 water would be considered a floating 

 pier. 



Structure Functions 



Buoys are most commonly used as 

 navigational aids to mark channels, 

 shoals, harbor entrances, etc. Some- 

 times buoys have lights, reflectors, or 

 horns mounted on them. Buoys are also 

 used as markers for sunken objects and' 

 for suspending analytical instrumenta- 

 tion, such as current, wave, or water 

 quality monitoring equipment. 



Floating platforms are flat struc- 

 tures which are generally larger buoys 

 or floats. They are used for recreational 

 purposes, such as swimming and diving, 

 or commercial purposes such as selling 



fishing supplies. Larger platforms used 

 for construction or drilling would nor- 

 mally be considered as ships, barges, or 

 hulls. 



Site Characteristics and Environmental 

 Conditions 



Buoys are utilized in all types of 

 energy environments, while floating 

 platforms are usually used in relatively 

 sheltered areas. 



Placements Constraints 



Engineering. The sizes and shapes 

 of buoys and floating platforms depend 

 on the function. For example, buoys or 

 floats used in swimming areas or for 

 mooring recreational craft would be 

 smaller and of lighter construction than 

 a buoy or float used in open water. 



The site and method of placement 

 should be considered carefully. It is 

 important that buoys and platforms be 

 properly anchored according to their 

 size and weight. Areas where bottom 

 sediments frequently shift should be 

 avoided. Water level fluctuations 

 should be considered when designing an 

 anchor system. Platforms, buoys, and 

 attached vessels should not interfere 

 with navigation. 



Socioeconomic. Platforms and buoys 

 should not interfere with public use of 

 the waterway. It is advisable to design 

 them so that they are clearly visible to 

 boaters. The presence of buoys and 

 floats is generally accompanied by in- 

 creased human usage of an area. The 

 secondary impacts of the human usage 

 should be considered. 



Biological . If drums or barrels 

 are utilized as floats, those once con- 

 taining toxic substances are not suit- 

 able. It is advisable to coat foam 

 floats to prevent chips and flakes from 

 littering the water. To avoid contami- 

 nation, all coatings must be dry before 

 placing floats in the water. The sub- 

 merged surfaces of buoys and floats and 

 the anchor system offer habitat for var- 

 ious types of attached organisms. They 

 also supply refuge for various types of 

 fishes. 



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