Fish Standing Stock at the Artificial Reefs ofPulau ... - seafdec.org.my

More documents

Recommendations

Info

Fish Standing Stock at the Artificial Reefs ofPulau Payar, KedahZaidnuddin, I. and Abdul Razak, L.Fisheries Research Institute, 11960 Batu Maung, Penang,Malaysia(Cited as) ZAIDNUDDIN, 1. and L. ABDULRAZAK.1999. Fish standing stock observation atthe artificial reefs ofPulau Payer, Kedah. In International Conference on the Straits ofMalacca. X.Gopinath, X.Ibrahim, X.. Nik, F. Yusoph & M. Shariff (eds), p.OOO-OOO. Population Managementand Mitigation in the Straits ofMalacca Section.Since the early 1970's, the Department of Fisheries Malaysia has built artificial reefs in Malaysianwaters. The program began in the straits ofMalacca in the form of closely tied tyre reefs and thenprogressed to pyramid modules. This study was carried out to determine the effectiveness of theartificial reefs deployed and the fish standing stock in its vicinity. The reefs observed in PulauPayar were oftyres, concrete culverts, scuttled boat reefs and laminated concrete pillars. The reefswere ideal for smdy a..s.theywere not disturbed by fishing activity and could be used as an indicatorof processes that happen in other artificial reefs. The fish standing stock at tyre reefs were observedto be the highest compared to the other artificial reef forms. Resident type fishes for exampleEpinephalus sp., Anypherodon leucogrammicus Zanclus sp. and Heniochus sp. were abundant atthe artificial reef structure. Other fishes such as the lutjanids were observed to roam the reefs forfood and protection. Colonisation of artificial reefs was observed to depend on depth and totalsuspended solid level. Scleractinian corals and soft corals were observed to colonise the shallowartificial reefs but not the deeper and sediment covered tyres.The Department of Fisheries Malaysia has deployed more than 3 million tyres as artificial reefs in....thc-Malaysian waters (Wagimanet al.; ·1994). The tyres have been dep loyed in modules-covering-54 sites in the Peninsular Malaysia, 6 in Sarawak and 7 in Sabah. Fish standing stock is one oftheway to describe the effectiveness of an artificial reef programme. Bonsack (1994) compared the.., - fish.at different reef modules to determine how-artifieial reef sizes-influeneed fish aggregation ·atdifferent types of reefs. The communities inhabiting artificial structures deployed in an open.ecosystem may be influenced by various factors, for example, emigration, immigration, breeding,natural mortality and predatory mortality.Fishes can be attracted to artificial reefs in a short time.Abdul-Razak and Ismail (1992) reported that species such as Scolopsis sp. and Caesio sp. wereobserved around artificial reefs within 4-5 days. Even with a small module, a total number oftwenty species were observed. The contribution of the structure to production of fish versusconcentration of existing fish can be further elaborated through the study of fish communitiesaround the reef and the manner in which the area is protected.There are many types of spawning behaviour in marine fishes. These include oviviviparity (sharkand rays), nesting (damselfishes and triggerfishes) and scattering or cast spawning (groupers andlutjanids)(Allen, 1997). In cast spawning species, recruitment in an area would probably dependon water currents and juvenile concentrations trapped by eddies.Shark, squid and salmon select
their breeding ground and deposit their young making management of these species possible ifthespawning areas are known (Wagiman et al., 1994).Determining the success of artificial structures in increasing the fish populations in the areasurrounding a reef can be done through various ways and method. Fishing near the surface ofartificial reefs is one of the best way to determine the stock of fishes in that area. Wagiman et al.(1994) reported a maximum catch of20 kg fish per sampling in an area of 1,800 m 2 • Food chainbase is another measure by which the efficiency of an artificial reef structure can be established.Food supply in an artificial reef area can be divided into different categories such as algae,mollusc and benthic invertebrates. Usually after a few week of submergence in the water, algae,barnacles and oysters will start to colonise the structure (Latun and Wong, 1988). Colonisation ofoysters took about two months after the artificial reef was deployed (Abdul-Razak and Ismail,1992). Other supply of food for example plankton, zooplankton were usually abundant unless thewater is polluted. Open ecosystems are interdependent and food supply and recruitment maycome from other areas carried in by the water current.Understanding the contribution of artificial reefs to the marine ecosystems can be done throughthe study of resident organisms, such as groupers and chaetodids. Groupers, for example, havean interesting breeding behaviour because they are all born as females (protogynous) andmasculirization depends on several factors such as individual size and population needs. Groupersalso congregate to mate and the individuals mature at certain sizes before breeding. Bullock andSmith (1991) reported that the Mycteroperca microlepis, mature around 550 rom total lengthwithin 3-6 years. Artificial reefs besides being a safe area for young fish are also nesting groundsfor larger groupers. Artificial reefs create more safe areas for the species to grow and hide asthese areas are more difficult to fish than the natural shallow reefs.a) Determine the number of groupers species andb) Determine size range ofthe grouper species at Pulau Payars artificial reefsThe fish standing stock at artificial reefs will be described in a limited context as the standing stock ofgroupers
Page 4 and 5: The study was done at Pulau Payar's
Page 6 and 7: * density/10m square 1 rare 1-2indi
Page 8 and 9: eefs supply the environment with fo

Fish Standing Stock at the Artificial Reefs ofPulau ... - seafdec.org.my

Create successful ePaper yourself

Delete template?

Save as template?