KARACHI: Invasive species have emerged as a major problem in many countries with expansion in trade and traffic volume affecting their ecology, economy and health, said marine experts at an international workshop held on Monday.

A number of invasive species have been introduced in Pakistan’s freshwater to increase fish productivity but no research has ever been carried out to examine their impact on the ecosystem, according to them.

The three-day workshop on ‘Bio-invasion and ballast water management’ was organised by Saarc Coastal Zone Management Centre in collaboration with Climate Change Division at a hotel.

Experts from Sri Lanka, the Maldives, Bangladesh and Afghanistan also attended the event.

Dr Shahid Amjad, former director general of the National Institute of Oceanography who is currently working at the Institute of Business Management, explained that as soon as a solid object came in contact with seawater, organic matter started settling on its surface in the form of a slimy layer of glycoprotein film.

The film, he said, contained organic nutrients that attracted different marine micro-organisms, plants and animals to the object immersed in the seawater. With a very high settlement and growth rate, these micro-organisms, he said, seriously affected the efficiency of the equipment/object they accumulated on. There was also a risk of endangering another environment when one vessel carried invasive species to another place.

“Worldwide, over 400 marine organisms are important in causing fouling problems. This causes a very bad effect on fisheries production, shipping and the coastal industry and infrastructure due to infestation,” he said, adding that biofouling also led to frequent closure of recreational and tourism facilities.

The ballast water of a vessel, the audience was informed, had been recognised as a major source of introducing invasive species. All modern seagoing sea vessels carried huge amount of ballast water that was often pumped into tanks from coastal waters in one region and discharged at the next port of call, wherever cargo was loaded, it was said.

The discharge, it was said, might pose serious ecological, economic and health problems due to the multitude of marine species carried in ships’ ballast water. Reference were made to different countries where invasive species wreaked havoc with local environment and were controlled with a lot of effort.

Presenting slides on the impact of bio-invasive species on Pakistan fisheries, Mohammad Moazzam Khan working as a technical adviser on marine resources with World Wide Fund for Nature-Pakistan said a number of species such as trout, grass carp, silver carp, bighead carp, tilapia and Pangasius had been introduced in Pakistan’s freshwater in order to increase fish productivity in saline water.

“No study has ever been conducted to examine the impact of these species on the ecosystem. Our country also lacks reliable data on indigenous marine flora and fauna that makes the identification of the invasive species difficult,” he said while showing a list of fish species that had been misidentified.

Representing the Pakistan National Shipping Corporation, retired captain S. Hashim Hasnain highlighted how the world developed anti-fouling system that was defined as a coating paint, surface treatment or a device used on a ship to control or prevent attachment of unwanted organisms.

“Biofouling occurs everywhere but is most significant economically to the shipping industries, since high levels of fouling on a ship hull significantly increases drag, reducing the overall hydrodynamic performance of the vessel and increases the fuel consumption. This contributes to marine pollution,” Mr Hasnain said.

He said people used different material, for instance lime, arsenal and mercurial compounds and pesticides, to keep hull safe until 1960 when one of the most effective anti-fouling paints containing tributytin, a highly toxic chemical, was developed. However, he said, environmental studies showed that such compounds persisted in water and in sediments, killing sea life other than that attached to the hulls of ships and possibly entering the food chain. “The chemical was later internationally banned,” he said.

The Pakistan National Shipping Corporation used biocide-free paint to keep ship hull safe, he claimed.

Climate change division director general Irfan Tariq, Dr Hina Saeed Baig of the NIO, Prof Ghazala Siddiqui and Dr Furqana Chaghtai from Karachi University’s Centre of Excellence in Marine Biology also spoke.

Published in Dawn, August 26th, 2014