有效的人工魚礁

防波堤的設計原意旨在保護範圍內船隻及建築物,免受嚴峻天氣及強勁風浪的侵襲。不過,原來防波堤更可發揮多項令人意想不到的功能!

有效的人工魚礁
許多研究發現,這些人工海岸防護建設很多時能提高周邊海洋生物的多樣性。近數十年來,由於防波堤的形狀、建築方法及擺放位置,很多時都成為了大型人工魚礁,因為此等覆蓋範圍廣大的硬底環境能吸引更多珊瑚、軟體動物及其他海底生物群棲身於此,正好為魚類提供絕佳的棲息環境及充足的食糧(Stephens et al., 1994; Svane and Peterson 2001; Bulleri 2005; Burt et al. 2009)

另外,亦有研究指遊艇港和海堤上常發現有活躍珊瑚聚居(Tan et al. 2012),因這些人工魚礁可將棲息於周邊天然珊瑚礁的魚類吸引過來並迅速繁殖,相比周邊的天然珊瑚礁,其魚類和海底生物群的繁殖情況無論在數量、密度及多樣性各方面表現都更為優勝。(Bohnsack 1989; Bohnsack et al. 1994; Lincoln-Smith et al. 1994; Stephens et al. 1994; Pickering and Whitmarsh 1997; Rilov and Benayahu 2000; Abelson and Shlesinger 2002; Pondella et al. 2002; Perkol-Finkel and Benayahu 2004; Burt et al. 2009)。在香港,萬宜水庫東壩就是最能體現多樣化人工魚礁魚群的成功例子(Wilson 2002)

魚類成長的溫床
其實在防波堤保護下的遊艇港都可成為魚群的理想避風港,由於遊艇港內不容許任何捕魚活動(包括垂釣)及嚴格控制水質,所以魚類能在受保護的環境下迅速繁殖,長遠令港外的漁業資源變得更豐富,亦可確保該區捕魚業的可持續發展。

更多可能性

防波堤除了用作人工魚礁有顯而易見的好處及成效外,亦有許多建議指防波堤可利用海浪產生再生能源。憑藉嶄新設計,防波堤的潛在用途可說是無可限量,例如橫切面呈U形的防波堤設計不僅視覺上顯得更薄更美觀,亦可收提高穩定性之效,而此結構中的水體更為這個防波堤帶來很多的潛在的用途,實用性及康樂性俱備。我們誠意邀請 閣下與我們分享您的嶄新意念,以使這個防波堤結構及水體可以得到最佳的運用。

參考資料:
Abelson A., Shlesinger Y. (2002) Comparison of the development of coral and fish communities on rock-aggregated artificial reefs in Eilat, Red Sea. ICES J Mar Sci 59:122–126

Burt J., Bartholomew A., Usseglio P., Bauman A., Sale P.F. (2009) Are artificial reefs surrogates of natural habitats for corals and fish in Dubai, United Arab Emirates? Coral Reefs 28:663–675

Bohnsack J.A. 1989. Are high densities of fishes at artificial reefs the result of habitat limitation or behavioural preference?. Bull. Mar. Sci. 44, 631-645. Bohnsack J., Harper D., McClellan D., Hulsbeck M. (1994) Effects of reef size on colonization and assemblage structure of fishes at artificial reefs off southeastern Florida, USA. Bull Mar Sci 55:796–823

Lincoln-Smith M., Hair C., Bell J. (1994) Man-made rock breakwaters as fish habitats: comparisons between breakwaters and natural reefs within an embayment in southeastern Australia. Bull Mar Sci 55:1344

Perkol-Finkel S., Benayahu Y. (2004) Community structure of stony and soft corals on vertical unplanned artificial reefs in Eilat (Red Sea): comparison to natural reefs. Coral Reefs 23:195–205

Pickering H., Whitmarsh D. (1997) Artificial reefs and fisheries exploitation: a review of the ‘attraction versus production’ debate, the influence of design and its significance for policy. Fish Res 31:39–59

Pondella D., Stephens J., Craig M. (2002) Fish production of a temperate artificial reef based on the density of embiotocids. ICES J Mar Sci 59:S88–S93

Rilov G., Benayahu Y. (2000) Fish assemblage on natural versus vertical artificial reefs: the rehabilitation perspective. Mar Biol 136:931–942

Stephens J.S. Jr., Morris P.A., Pondella D. J., Koonce T.A., & Jordan G.A. (1994) Overview of the dynamics of an urban artificial reef fish assemblage at King Harbor, California, USA. Bulletin of Marine Science, 55(2-3): 1224-1239.

Tan Y.Z., Ng C.S.L., Chou L.M. (2012) Natural colonization of a marina seawall by scleractinian corals along Singapore’s east coast. Nature in Singapore, 5: 177–183

Wilson K. (2002) New reef fish from High Island dam dollos. Porcupine! 26. Newsletter of the Department of Ecology & Biodiversity. HKU. < http://www.hku.hk/ecology/porcupine>