The Shrimp And The Mangrove

Related Information
Endangered Seas: Shrimps That Grew Into Monsters

Living Planet: East African Marine Ecosystems














 
By Salman Rashid*
For years the people of Sonmiani Bay in Pakistan have lived off the shrimp harvest and the mangrove forest but only now are they learning that the decline of one is related to the destruction of the other.

Lahore, Pakistan: There are 62 species of mangrove in the world and Pakistan boasts eight of them. Once they were in vast forests along the coastline but today there are just a few dwindling pockets, thanks to years of thoughtless exploitation and, more recently, the destruction of habitats.

The mangrove is an extremely useful tree. Its luxurious foliage makes excellent fodder, the bark yields tannin and the wood provides not only fuel but also - because it is termite-resistant, excellent construction material. Hardly surprising, then, that Pakistan's mangrove forests have been plundered.

But that is not the only reason for the disappearance of large swathes of forest. Mangroves can tolerate only a certain amount of salinity, so they favour mudflats by river mouths. In recent years, the flow of fresh water into the sea has been increasingly restricted by dams and irrigation schemes, so a build-up of salinity has slowly depleted the forests - with further damage arising from growing amounts of domestic and industrial waste.

But while environmentalists noted the decline with deepening concern, the communities that benefited from the mangroves saw no cause for alarm. The trees were the gift of God and, no matter how ruthlessly they were they exploited, they would always renew themselves. Little did they realise that the decrease in their shrimp harvest resulted largely from to the destruction of the mangroves, whose tangled roots served as nurseries for shrimps, crabs, and several species of fish. Then, two years ago, WWF-World Wide Fund For Nature-Pakistan began a project to preserve mangroves. It identified Sonmiani Bay, just over an hour's drive north of Karachi, as a prime site because it contains three of Pakistan's eight species: Avicennia marina, Ceriops tagal, and Rhizophora mucronata.

At first the local community was unwilling to participate in an apparently meaningless scheme, but the local schoolmaster, Gul Mohammed, understood the project team's message and offered his otaq, a sort of meeting-house for men, as the WWF field office. Thus began an informal cycle of education in the otaqs and tea shops of the area.

Before long mangrove nurseries began to be established. The seedlings germinate on the mother plant, and when they are about 20-25 cm long, they drop off and take root in the soft mud below. This works well on ebb tide when the mud is exposed, but seedlings falling during high tide are nearly always destroyed. At high tide, however, seed harvesting could be done with nets and the nurseries were soon flourishing. By June 1996 the first seedlings were being transplanted on two sites in 40 hectares of bog. Most survived and today two clumps of healthy mangrove trees, barely above a metre in height, are evidence of success.

Meanwhile, the education programme continues. When signs were erected reading, 'Grow mangrove, harvest shrimp', few locals saw the connection, but today the relationship is widely understood and WWF hopes to rehabilitate an additional 100 hectares of forest. Even that is only a beginning, though. With full participation of a community converted to the idea of sustainable use, the plan is to bring 700 hectares of mangrove under management in Sonmiani Bay.

Much work remains to be done before that stage is reached, but WWF hopes it will eventually be able to hand over the project to the community to manage. That will be a mark of acceptance that the shrimp and the mangrove are inter-dependent and that not even the most bountiful of God's gifts can last forever without the help of those who make use of it. (587 words)

*Salman Rashid is a freelance journalist based in Lahore.