Macroalgal Biomass and Cover 
Benthic green macroalgae coverage and biomass measurements were conducted as part 
of several studies in Yaquina Estuary between 1998 and 2004 (Table B.7). Most of the 
measurements were made during the dry season (May - October) in the marine-dominated sector 
(Zone 1). Although both non-random and random sampling designs were employed in different 
survey efforts, all the macroalgal data within Yaquina Estuary (WED unpublished data; Kentula 
and DeWitt, 2004) were combined for analysis. To obtain a regional perspective, the data from 
the Classification Study (Section 4.2) also were summarized for comparison (Lee et al., 2006). 
Table B.7. Sources of ground survey macroalgae data used in this study. All data were 
collected by WED. Random and non-random sampling designs are denoted by R and 
NR, respectively. 
Period 
Zone 
No. of Samples 
Sampling 
Zone 1 
Zone 2 
1998 
1 
69 
- 
NR 
1998-99 
1 
65 
R 
1999-2003 
1 
4159 
- 
R 
2001-2002 
1 
2094 
- 
NR 
2002-2004 
1 
140 
- 
NR 
2004 
1 & 2 
47 
53 
R 
To examine seasonal variability in benthic green macroalgae cover and biomass, six band 
transects were established within Zone 1 of Yaquina Estuary during 1999. These sites (I -VI, 
respectively) were situated 3.9, 5.0, 6.3, 7.8, 8.6, and 10.6 km from the ocean end of the jetties at 
the mouth of the estuary (Figure 2.1). The transects were 30 m wide, and extended 100 m 
upslope from the MLLW tide line perpendicular to the channel. Along each transect, sampling 
stations were regularly spaced at 10 m intervals. At Sites II and III, the bathymetric slope was 
lower than for other sites, and in August 1999 the transects were extended to about 350 m from 
MLLW, with the additional sample stations situated at ~ 40m intervals. Stations along the 
transects were generated with a random number generator prior to field sampling. For each 
station, three randomly-selected distances between 1 and 30 m perpendicular to the sampling 
transect were sampled. Between June and December 1999, most of the sites were sampled every 
other week during daylight low tides, while less frequent sampling of these sites continued 
through May 2000. 
144 
