A comparison of species richness at 51 coastal and estuarine sites in south
ern Maine is given, encompassing the area from Cape Neddick, York, to Fort
Foster, Kittery, and including the Brave Boat Harbor salt marsh (York/Kitte
ry). A total of 148 taxa was recorded, which is relatively high compared to
other coastal or estuarine areas in northern New England. Seaweed populati
ons exhibited three major distributional patterns: coastal (41%), coastal-e
stuarine (51%), and estuarine (8%). Perennial species dominated open coasta
l and outer estuarine locations, while annuals were most conspicuous at inn
er estuarine sites. Twenty-nine taxa were restricted to a single site (2% o
ccurrence), whereas 19 were found at 21-36 sites (41-71% occurrence). Diver
sity in Brave Boat Harbor's main tidal channel was relatively high (83 spec
ies), presumably because of coastal and estuarine influences, diversity of
habitats, and limited anthropogenic impacts. Six new or uncommon seaweeds w
ere recorded from Brave Boat Harbor, including the invasive green alga Codi
um fragile subsp. tomentosoides, the green algal epiphyte Urospora curvata,
the tubular opportunistic brown alga Melanosiphon intestinalis, the entang
led or partially embedded ecads Fucus vesiculosus ecad volubilis and F. spi
ralis ecad lutarius, and a dwarf embedded moss or "muscoides-like" Fucus. T
he prolific growth of psammophytic populations of F. spiralis on sandy bluf
fs at Brave Boat Harbor is also unique, as it typically grows on hard subst
rata within contiguous muddy estuaries. It was most abundant in the outer t
hird of the Harbor, along with its detached ecad lutarius. Ascophyllum nodo
sum ecad scorpioides and F. vesiculosus ecad volubilis grew commonly as det
ached or buried populations in the interior parts of the Harbor, while the
"muscoides-like" Fucus was found on outer high sandy marsh surfaces.