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Fishery Bulletin 108(2) 
were black rockfish ( Sebastes inermis), jack mackerel 
( Trachurus japonicus), bambooleaf wrasse (Pseudola- 
brus sieboldi), chameleon goby (Tridentiger trigono- 
cephalus) and whitespotted pigmy filefish ( Rudarius 
ercodes ) (Fig. 4); the former three species are tar- 
geted in commercial fisheries, whereas the latter two 
are prey species of other commercial species. Jack 
mackerel is pelagic and migratory, and the other four 
species are demersal and relatively sedentary. The 
typical fishes showing high preference for the cedar 
ARs were black rockfish, sunrise sculpin (Pseudo- 
blennius cottoides), black sea bream (Acanthopagrus 
schlegelii), whitespotted pigmy filefish, thread-sail 
filefish ( Stephanolepis cirrhifer), and finepatterned 
puffer ( Takifugu poecilonotus). Two species of goby (7s- 
tigobius hoshinonis and T. trigonocephalus) were most 
abundant in the broadleaf ARs (Fig. 4). Redspotted 
grouper ( Epinephelus akaara) and barface cardinalfish 
( Apogon semilineatus) were most abundant in the PVC 
ARs. Jack mackerel and bambooleaf wrasse were the 
most abundant species during the entire census period 
(Table 2), but they did not show any clear preference 
for a particular type of AR. 
Maximum, minimum, and average body length in 
two highly abundant and commercially important spe- 
cies, black rockfish and jack mackerel, are plotted for 
each type of artificial reef in Figure 5. Black rockfish 
generally had a wide range (1.5-16 cm) of body length, 
whereas jack mackerel had a smaller body size range 
(4-12 cm). This was prominent in cedar ARs, especially 
shortly after the deployment of the AR (Fig. 5A). 
A bryozoan community was established within two 
to three months of deploying the cedar ARs. Other en- 
crusting epibenthic assemblages, such as Porifera, Cni- 
daria, Mollusca, and Annelida, gradually formed on the 
broadleaf and PVC ARs after one year. The upper sec- 
tions of the ARs attracted these encrusting organisms 
more rapidly than the lower sections. In the fourth year, 
some of the upper sections of the cedar and 
broadleaf ARs began to decay because of foul- 
ing by encrusting organisms, particularly wood 
boring piddock (Martesia striata). Crabs ( Cha - 
rybdis japonica) and sea cucumbers ( Stichopus 
japonicus) were common in all types of ARs. 
At least four fish species, black sea bream, 
Temminck’s surfperch (Ditrema temmincki), 
whitespotted pigmy filefish, and thread-sail 
filefish, were observed feeding on the encrust- 
ing organisms on and around the cedar ARs. 
Conger eel ( Conger myriaster), two species of 
groupers, and large individuals of bambooleaf 
wrasse resided inside the PVC pipes. Some fish, 
such as thread-sail filefish and redfin velvetfish 
( Paracentropogon rubripinnis), overwintered, 
showing minimal movement in the cedar ARs 
through the winter. 
Fish assemblages in the adjacent habitat 
Visual censuses of the areas adjacent to the 
ARs revealed that both fish species richness 
and abundance showed clear seasonal changes 
corresponding to variations in sea bottom water 
temperature (Fig. 6). A total of 73,922 fish indi- 
viduals from 90 species were recorded from 
23 May 2002 to 8 May 2008 in transects 1-3. 
There was no significant change in fish species 
richness or abundance along any of the three 
transects after the deployment of ARs (P>0.5, 
ANCOVA; Table 3). Species-to-species analy- 
sis revealed that although there were several 
cases of increases or decreases in abundance 
after deployment, there was no evidence of a 
systematic decrease in species richness along 
transect 1, in which one species decreased and 
four species increased after the deployment (see 
far-right column in Table 2). The average (±SE) 
number of individuals in the entire census area 
of the adjacent habitat was 171 ±12.6 per 400 m 2 . 
_CO 
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z 
1 
1000 
3 
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Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr 
2004 2004 2004 2004 
Figure 3 
Species richness, fish abundance, and fish biomass associated 
with each type of artificial reef on each observation day between 
May 2004 and April 2008. Plotted data are averages of the two 
monthly observations carried out at each triplicate artificial 
reef. Note log scale for individuals and biomass plots. 
