Speich and Wahl 



Chapter 30 



Marine Habitat Preferences, Variability in Washington 



Various Points 



^H Spring 

 Points: PL Wilson, Cattle Pt, Green Pt, PL Roberts 



Passages - San Juan Islands 

 LOCATIONS 



Summer 



Fall 



Admiralty Inlet 

 Winter 



Figure 5 Seasonal abundance of Marbled Murrelets, areas of tidal activity. 



Vane- .s Points 



^H Spring I 

 Points: Pt Wilson, Cattle Pt., Green PL, PL Roberts. 



Passages - San Juan Islands 

 LOCATIONS 



Summer 



Fall 



Admiralty Inlet 

 Winter 



Figure 6 Seasonal presence of Marbled Murrelets, areas of tidal activity. 



(table 1). The highest calculated densities occurred in Eelgrass 

 and Sand substrate in Whatcom and Skagit Counties during 

 the summer. Cobble and Rock substrate of "Assorted Areas" 

 during the winter, and in the Sand and Mud substrate in the 

 San Juan Islands during the fall. The last habitat type had 

 overall the highest determined seasonal densities. 



Overall within this habitat group, the proportion of 

 censuses with murrelets was below 40 percent (table l,fig. 

 10). The only exceptions were the spring and summer periods 

 of the Sand and Mud substrate in the San Juan Islands, 

 however small sample sizes (table 1) suggest caution in 

 interpreting those values. As elsewhere, there is considerable 

 seasonal within and between habitat variation. 



Abundance and Occurrence by Habitat Types - 

 Pacific Coast 



Grays Harbor Channel and Shelf Waters 



Over a 23-year period, Marbled Murrelets were recorded 

 in Grays Harbor channel in every month. The general pattern 

 of occurrence was one of high average densities during the 

 spring, fall, and winter months (table 2, fig. 11), and higher 

 densities in habitats closer to shore. Overall, the highest 

 densities occurred in Grays Harbor Channel, followed by 

 Grays Harbor Channel to 20 m depth, and 20 to 50 m depth. 

 Only rarely were they recorded in deeper habitat areas. The 

 highest densities occurred during the spring months and highest 

 average density occurred in Grays Harbor Channel in March. 



USDA Forest Service Gen. Tech. Rep. PSW-152. 1995. 



319 



