Comparison of temporal trends using adjusted and
unadjusted bivalve data. Direction of arrow
indicates increases or decreases from 1993 to 1997.
* = probability that slope of trendline was different
from zero was < 0.2. ** = probability that slope
of trendline was different from zero was < 0.1.
*** = probability that slope of trendline was different
from zero was < 0.05. NA = not analyzed.