1. Fouling communities developed on the test panels were investigated during the period from January 1981 to July 1981 in Tungnyang Bay, Korea.
2. The fouling assemblages consisted of representatives of seven phyla and about 34 species, as follows: 8 polychaetous annelids, 8 crustaceans, 7 mollusks, 6 coelenterates, 2 bryozoans, and 2 others.
3. Amphipod crustaceans were the earliest and most abundant settling foulers. They were composed of three caprellids and three tube-building gammarid amphipods.
4. The unexpectedly high abundance of amphipod crustaceans presumably resulted from the high turbidity. Therefore, the concentration of suspended solids in the study area may play a major role in determining the variability of the amphipod populations in a state of initial colonization of the fouling assemblages.
5. Polychaetes (nereids and polynoids), mollusks, and other fouling organisms including hydroids, actinians, bryozoans, turbellarians, and nemertineans were lately represented in July 1981.

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Luxuriant growth of Ulvaceae covering a large area was observed in the lower intertidal and sub-tidal zone on a sander of Uranouchi Inlet, Tosa Bay, southern Japan. Water temperature in the survey area was 15.0-15.9°C in February and attained 29.8°C during summer season. Chlorinity ranged 17-18‰ during autumn to spring and became lower during rainy season to summer. The concentration of NH₄-N, NO₂-N and NO₃-N ranged 0.07-4.9μg at./l, 0.01-0.40μg at./l and 0.07-0.49μg at./l respectively during survey period in 1981. Phosphate-phosphorus was 0.3-2.6μg at./l for the same period.
The Ulva bed was found vertically between-2.0∼1.4m D.L. and 100∼200m horizontally across the sander. Fronds of Ulva sp. on the Ulva bed appeared to be growing from May and attained a mean height of 50cm in July. Maximum biomass of the Ulva bed was 980g w.w./m² in mid August, with a distinct decrease starting from November.
In the transplant experiments, the optimum depth for maximum growth was within one meter below the surface. The frond area of Ulva in the surface layer was 6.8 times that of the initial after 7 days. Fruiting fronds were observed to appear from May to December, but there were many fruiting fronds on the bed during the period from October to November.

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The settlement of mussel larvae in mussel beds developing on piers was observed from March to May, 1985 in Kurihama Bay near the mouth of Tokyo Bay. Settlement depth was investigated using fouling ropes suspended at selected depths in the coast of Hiratsuka. Number of D-shaped early larvae and veliconcha late larvae peaked on April 5 and 12 respectively. Number of plantigrades settling on fouling ropes was highest during the period April 10-17. Number of mussels settling in the mussel beds on the piers in the less than 10mm size class began to increase after April 23 and reached 40% of the total in the beds on May 8. Mussel settlement on the fouling ropes submerged at different depths for a month from the end of April was observed. Settlement was most abundant in the middle layer.

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The infestation of barnacles with Polydora spp. is discussed in relation with the size and structure of the host. The frequency of barnacles attacked by Polydora was relatively low in small sizes (up to 10mm in diameter), increasing to a high rate in the largest sizes during May to July. Barnacles infected with Polydora decreased in number markedly through late fall and no parasitism was observed in the winter. Polydora seems to attack specific regions of the shell plates for all the data combined. It is considered that barnacles infected with the pest die during August and September.

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In order to study the settlement of puerulus larvae of the japanese spiny lobster Panulirus japonicus (VON SIEBOLD), the fouling communities developed on a floating artificial reef were examined during the period from 1985 to 1986.
The puerulus larvae may settle as a result of PHILLIPS'S“grasping response”, but they presumably prefer to settle during a stage in the development of fouling community on the collector which is suitable for them.
In the“conditioning”of a collector for the puerulus larvae, therefore, the procedure should be carried out according to the locality, season, year, etc.

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