Preven­tion, early de­tec­tion and quick re­sponse are key

New Straits Times - - Opinion -

SA­HA­BAT Alam Malaysia is alarmed over the ir­re­versible dam­age to the en­vi­ron­ment caused by the in­va­sion of an alien fish species, the African cat­fish

Alien species that en­ter a bi­o­log­i­cal niche where they have never be­fore ex­isted can be dif­fi­cult to con­trol and pre­dict, re­sult­ing in cat­a­strophic eco­nomic con­se­quences, but the author­i­ties do not see it that way. As more in­vaders are ac­cu­mu­lat­ing in ecosys­tems, it can be ex­pected that they will be more dis­rup­tive.

The pres­ence of African cat­fish in our wa­ter­ways is dis­turb­ing as it is a top predator, and a se­ri­ous threat to na­tive fish. Lo­cal fish­er­men have ex­pe­ri­enced low catches with some re­turn­ing home empty-handed.

The African cat­fish will feed on any fish species. They re­spond quickly to new food sources and change their feed­ing pat­terns to match the or­gan­isms avail­able. Young fish feed mostly on small in­ver­te­brates in shal­low in­shore ar­eas.

Var­i­ous fac­tors make this species dif­fi­cult to con­trol: om­niv­o­rous diet, di­rect air breath­ing, abil­ity to walk on land, bur­row­ing ca­pa­bil­i­ties and abil­ity to hide in be­tween veg­e­ta­tion. A 2kg African cat­fish can pro­duce about 45,000 eggs.

Stud­ies con­ducted in 1972 in cen­tral Africa showed that this species has pro­found neg­a­tive eco­log­i­cal ef­fects on aquatic in­sect com­mu­ni­ties, as well as am­phib­ian and in­ver­te­brate pop­u­la­tions. In­sect di­ver­sity in the Ch­leoptera or­der has been re­duced by up to 78 per cent and Hemiptera by 66 per cent.

The African cat­fish could also fa­cil­i­tate the spread of par­a­sites, lead­ing to ex­tinc­tion of in­dige­nous fish species.

The un­prece­dented pace of in­tro­duc­tion of this alien fish is from fish farm breed­ing, hatch­eries for com­mer­cial pur­poses, re­lease of the fish into rivers and ponds by the pub­lic, im­port for the aquar­ium fish trade and other chan­nels.

The im­pact of the African cat­fish or other alien fish species on our en­vi­ron­ment should be treated with the same con­cerns as oil spills. It re­quires in­tense in­ves­ti­ga­tion with em­pha­sis on de­vel­op­ing tech­niques for con­trol­ling its dis­per­sal.

Many cit­i­zens, key sec­tor groups and gov­ern­ments have a poor ap­pre­ci­a­tion of the mag­ni­tude and eco­nomic costs of the prob­lem. As a con­se­quence, de­lay in early de­tec­tion and poor rapid re­sponse ef­forts give in­vaders time to re­pro­duce and in­crease in num­bers, mak­ing con­trol dif­fi­cult. Fed­eral and state agen­cies need to mon­i­tor new in­va­sions.

The author­i­ties must re­alise the eco­log­i­cal costs of bi­o­log­i­cal in­va­sion in terms of ir­re­triev­able loss of na­tive bio­di­ver­sity and degra­da­tion of ecosys­tems. While the un­der­ly­ing causes of in­va­sive species threats are sig­nif­i­cant and global in na­ture, th­ese threats can be ef­fec­tively dealt with through col­lab­o­ra­tive ef­forts at the re­gional and lo­cal lev­els, es­pe­cially through preven­tion, early de­tec­tion and rapid re­sponse.

Fail­ing to ef­fec­tively ad­dress the in­va­sion would mean fail­ing to meet the cri­te­ria of the In­ter­na­tional Union for Con­ser­va­tion of Na­ture.

SAM calls on the Agri­cul­ture and Agro-based In­dus­try Min­istry and the Fish­eries Depart­ment to con­duct a sur­vey on the wa­ter­ways where the African cat­fish are found. There is a need to stop fish farm­ing of this alien cat­fish and to ban the im­port of the African cat­fish and all alien fish species.

S.M. MOHD IDRIS

Pres­i­dent, Sa­ha­bat Alam Malaysia

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