Common use of Shading Clause in Contracts

Shading. Bridges or ferry ramps would partially shade littoral areas, reducing primary productivity and possibly limiting the distribution of some algae, while extending the distribution of other taxa. Examples of the effects of partial shading on steeply sloped rocky intertidal areas were reported at Stations PEN-4 and PEN-4A (see Phase II Marine Reconnaissance Survey; Pentec, 2001), where the middle and upper intertidal elevations were relatively devoid of macroalgae. However, below MLLW (and out from under the influence of overhanging trees), a typically lush kelp-dominated flora was found. The presence of over-water structures (bridges, causeways, and ferry docks) might partially shade portions of the adjacent beach and subtidal bottom areas. The area under a dock or causeway would likely receive full- time shade, whereas the area under an elevated bridge section would not, because the shadow cast by structures high above the water would move across the water as the sun traversed the sky. Because the upper limits of many intertidal species, including eelgrass, are set by the degree of desiccation experienced (shading would reduce desiccation) shading by project structures would allow some species to extend their ranges upslope. However, since lower limits of vegetative growth are set by light level, net loss of eelgrass or kelp productivity would result from the project if deeper portions of beds were shaded. If this occurred, eelgrass or kelp bed habitat area would be incrementally reduced, reducing the area of refuge and rearing for juvenile salmonids during their migrations as well as for other aquatic organisms such as Dungeness crabs. Reduced eelgrass productivity would also decrease the eelgrass blade area available to support epiphytic crustaceans, which are an important food source for juvenile salmon.

Shading. Bridges or ferry ramps would partially shade littoral areas, reducing primary productivity and possibly limiting the distribution of some algae, while extending the distribution of other taxa. Examples of the effects of partial shading on steeply sloped rocky intertidal areas were reported at Stations PEN-4 and PEN-4A (see Phase II Marine Reconnaissance Survey; Pentec, 2001), where the middle and upper intertidal elevations were relatively devoid of macroalgae. However, below MLLW (and out from under the influence of overhanging trees), a typically lush kelp-dominated flora was found. The presence of over-water structures (bridges, causeways, and ferry docks) might partially shade portions of the adjacent beach and subtidal bottom areas. The area under a dock or causeway would likely receive full- time shade, whereas the area under an elevated a bridge section would not, because the shadow cast by structures high above the water would move across the water beach as the sun traversed traverses the sky. Because the upper limits of many intertidal species, including eelgrass, are set by the degree of desiccation experienced (shading would reduce desiccation) shading by project structures would allow some species to extend their ranges range upslope. However, since lower limits of vegetative growth are set by light level, net loss of eelgrass or kelp productivity would could result from the project if deeper portions of beds were the bed are shaded, resulting in reduced production, while shallower sections result in increased production. If this occurredoccurs, eelgrass or kelp bed habitat area would be incrementally reduced, reducing the area of refuge and rearing for affecting juvenile salmonids ▇▇▇▇▇▇▇ during their migrations migration as well as for other aquatic organisms such as Dungeness crabscrab. Reduced eelgrass productivity would also decrease the eelgrass blade area available to support epiphytic crustaceans, which are an important food source for juvenile salmon, and could therefore reduce the area of refuge for salmon and other small fish.