On the Fish Gathering Effect of the Artificial Reefs astertained by the Diving Observation XII : In case of the Open Sea off Kanoya City

As the result of the on the spot submerging observations of the artificial reef carried on the sea front of Kanoya City confronting to the eastern seashore of the gulf of Kagoshima, the following informations were obtaind. (1) The kind of the artificial reef was noted to be consisting of concrete block reef ; small sized used car ; F. R. P. Boat ; Pine Tree ; the water depth was 35~40m : the location was fixed at the sea bottom which was uneven and supplied with dull inclined side. (2) The species of the fish gathered around the artificial reef was as in the following ; Horse mackerel, Trachurus japonicus, Barface cardinalfish, Apogon semilineatus, Rock bream, Oplegnathus fasciatus, Crimson sea bream, Evynnis japonica : the artificial reef which schooled the heighest fish gathering effectivity was fixed supplied to be the concrete blocked one with tall height and accmulated into a sort of grand mass, and which was set at the location at which the front part was excavated suddenly into a sort of valley. (3) Around the small sized used car, some group of serranidae sp. was often under gathering, however, other than those were rarely observed, therefore the aptitude of them as a artificial reef was considered to be left to the further investigations.昭和57年12月,鹿児島湾の東海岸に面する鹿屋市の沖合の7個所の人工魚礁について潜水観察を実施した結果,下記の様な知見を得た。1) 魚礁の種類はコンクリートブロック,小型車,F.R.P.船,松樹で,これらの魚礁は,水深35~40mの複雑な海底地形の場所に多く設置されている。2) 魚礁に蝟集した主な魚種はマアジ,ネンブツダイ,イシダイ,イサキ,チダイである。蝟集効果の高い魚礁は山型で海底からの高さの高いコンクリートブロック魚礁及び前面が急斜面となっている海底地形の場所に設置された魚礁である。3) 小型車魚礁はハタ類を良く集めているが,他の魚種は少ない。従って魚礁としての適格性については今後検討すべきであろう