162 
Fish assemblages associated 
with three types of artificial reefs: 
density of assemblages 
and possible impacts 
on adjacent fish abundance 
Reiji Masuda (contact author ) 1 Yoshiaki Kai 1 
Masami Shiba 2 Asami Nakanishi 1 
Yoh Yamashita 1 Masaru Torikoshi 1 
Masahiro Ueno 1 Masaru Tanaka 3 
Email address for contact author: reiji@kais. kyoto-u.ac.jp 
1 Maizuru Fisheries Research Station 
Kyoto University 
Nagahama, Maizuru 
Kyoto 625-0086, Japan 
2 Ashiu Forest Research Station 
Kyoto University 
Miyama, Nantan 
Kyoto 601-0703, Japan 
3 University of Malaysia Sabah 
Locked Bag No. 2073 
88999, Kota Kinabalu 
Sabah, Malaysia 
Abstract— We evaluated the effective- 
ness of wooden artificial reefs (ARs) 
as fish habitat. Three types of ARs, 
made of cedar logs, broadleaf tree 
logs, and PVC pipes, respectively, 
were deployed in triplicate at 8-m 
depth off Maizuru, Kyoto Prefec- 
ture, Sea of Japan, in May 2004. Fish 
assemblages associated with each of 
the nine ARs were observed by using 
SCUBA twice a month for four years. 
Fish assemblages in the adjacent 
habitat were also monitored for two 
years before and four years after reef 
deployment. In the surveyed areas 
(ca. 10 m 2 ) associated with each of the 
cedar, broadleaf, and PVC ARs, the 
average number of fish species was 
4.14, 3.49, and 3.00, and the average 
number of individuals was 40.7, 27.9, 
and 20.3, respectively. The estimated 
biomass was also more greater when 
associated with the cedar ARs than 
with other ARs. Visual censuses of the 
habitat adjacent to the ARs revealed 
that the number of fish species and 
the density of individuals were not 
affected by the deployment of the ARs. 
Our results support the superiority 
of cedar as an AR material and indi- 
cate that deployment of wooden ARs 
causes no reduction of fish abundance 
in adjacent natural reefs. 
Manuscript submitted 29 January 2009. 
Manuscript accepted 14 December 2009. 
Fish. Bull. 108:162-173 (2019). 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National Marine 
Fisheries Service, NOAA. 
Habitat complexity plays a major role 
in the survival of young demersal 
fishes by providing a refuge from pre- 
dation (Ferreira et al., 2001; Scharf 
et al., 2006; Hamilton and Konar, 
2007). Fish species richness is highly 
dependent on the rugosity and vari- 
ety of growth forms in the habitat, 
whereas the height of vertical struc- 
tures is an important predictor of 
total fish abundance (Gratwicke and 
Speight, 2005). In this respect, arti- 
ficial reefs (ARs) are often deployed 
to improve the quality of habitat 
(Gorham and Alevizon, 1989). In 
addition to their role as refuges, ARs 
host encrusting invertebrates that 
can be consumed as prey by fishes 
(Seaman and Jensen, 2000). Fish are 
often more abundant at ARs than at 
natural reefs, probably because the 
vertical structures potentially allow 
more varied refuges for fish settle- 
ment and recruitment than the usual 
more moderately sloped bottoms of 
natural reefs (Rilov and Benayahu, 
2000; Reed et al., 2006). 
Although the deployment of struc- 
tures functioning as ARs may well 
have started long ago by fishermen 
in various localities around the globe, 
research on this subject is relatively 
recent (Seaman and Sprague, 1991). 
Two countries, United States and Ja- 
pan, have relatively long histories of 
nationwide projects on ARs. In the 
case of the United States, the main 
goal of deploying ARs has been to 
improve catch for recreational fish- 
ermen. Common materials used for 
these ARs have been waste products, 
such as automobiles, tires, and oil 
and gas platforms. The use of such 
products has caused environmental 
concerns, resulting in a shift toward 
the construction of ARs with concrete 
(Collins et al., 2002). In contrast, the 
purpose of Japanese deployments of 
ARs have primarily been to improve 
commercial fishery production, and 
governmental agencies have invested 
heavily in the construction of large 
ARs made of concrete and steel to be 
deployed in coastal areas. 
