shelf taxa ranged from 67 to 142 m' 2 (Table 3.5.4). In comparison, average 
densities of the 10 most abundant taxa in estuaries were much higher, ranging 
from 197 to 5,242 m' 2 (Nelson et al. 2005). 
In addition to inshore-offshore differences, there were notable regional 
variations in the dominant offshore fauna. Though many of these fauna have 
broad geographic distributions throughout the region (see next section), except 
for the polychaete Spiophanes bombyx, the same taxa did not appear as 
members of the 10 most abundant taxa consistently across all three states 
(Table 3.5.5A). The closest similarities were between Oregon and Washington. 
For example, the polychaete Mediomastus spp. and ophiuroid Amphiodia urtica 
were the two most abundant taxa in California, while in Oregon and Washington 
the same two species, the polychaete Magelona longicornis and bivalve 
Axinopsida serricata, were the two most abundant taxa. There also was less 
variation between NMS vs. non-sanctuary status. For example, at least half of 
the 10 most abundant taxa in NMSs were also dominant in corresponding non¬ 
sanctuary waters (Table 3.5.5B). 
95 
