‘Small islands more vulnerable to environmental degradation’

Updated 19 Nov 2020


A VIEW from the hitherto undeveloped islands. — White Star
A VIEW from the hitherto undeveloped islands. — White Star

KARACHI: Sindh Governor Imran Ismail has recently asked members of civil society to initiate a debate over their concerns on the Bundal and Buddo islands’ development, which he believed were originally based on myths. He has also raised some interesting points.

Responding to the concerns of environmentalists about the future of marine life after development of the islands, he said that there has been no environmental study so far on these two islands. Those who are raising objections don’t mention any study but share their concerns only. He said that the fact is that there is no marine life as such in these particular areas because of raw sewage.

The Sindh chief minister must respond to these points, but only after environmental and ecological studies are conducted by some reputed organisations, like the International Union for Conservation of Nature (UCN) and World Wildlife Fund (WWF). Since the governor has also mentioned the presence of raw sewage, the CM should direct the Sindh Environmental Protection Agency (Sepa) to conduct water quality analysis of the water surrounding the islands.

Sepa should conduct a water quality analysis to know whether Bundal and Buddo islands are surrounded by seawater or raw sewage

The governor has mentioned a contradictory point. Since the islands are surrounded by raw sewage, as he suggest, how can he talk of desalination at the same time? One cannot desalinate raw sewage, and if one talks about desalination, then the water surrounding the islands must be seawater. Experience shows that the islands are surrounded by seawater.

Bundal and Buddo Islands are located in Korangi, Phitti and Jhari creeks, along the Sindh coast. Bundal is the largest of all the islands, having a length of about eight kilometres. The island is about four-km wide in the north and one-km wide in the south. The northern area of the island has extensive growth of mangroves.

Water, waste disposal challenges

Small islands face a specific set of water and waste disposal challenges, related to their extreme fragility, anthropogenic impacts, climate change, lack of scale and isolation. Most modern water and waste management paradigms applied elsewhere need careful reconsideration in small islands.

Assuming groundwater management option is not viable, the only option available is that of seawater desalination.

Desalination plants are energy-intensive. It takes a multi-stage plant about eight to 10 kilowatt-hours (kWh) of energy to produce one cubic meter of fresh water from seawater. Traditional drinking water treatment plants typically use well under 1 kWh per cubic meter.

Environmental problems are associated with the desalination plants. Getting rid of brine is a big problem. Every two gallons a plant takes in, means production of one gallon of drinkable water and one gallon of brine water that is about twice as salty as when it came in. Most plants discharge this back into the same body of water that serves as the intake source, creating marine pollution.

Desalination plants have serious implications for sea life. Plants use open ocean intakes. These are often screened, but the desalination process can still kill organisms during intake, and inside the plant’s treatment processes.

Treated water produced by the desalination plants is devoid of nutrients, especially calcium and magnesium. Consumers may suffer from tiredness, weakness, headache, muscular cramps and impaired heart rate. In severe acute cases, brain oedema, convulsions and metabolic acidosis may occur.

Waste water (sewage) management has never been simple in small islands. Besides, the waste-water treatment plants are full of problems, producing poor quality of treatment effluent that does not meet the effluent discharge standards. Karachi’s existing waste-water treatment plants prove this point. This will lead to major unmanageable problems.

An important question is: where will the poorly treated waste water be disposed of? If surrounding seawater serves as a recipient water body, then, within a short span of time, the surrounding seawater will become heavily polluted.

Alternatively, if the waste water is transported to Karachi, it will be filled with polluted air. DHA’s Phase VIII is in the vicinity of the islands and its residents will have serious objections; more so, because the solid waste of the islands will also be transported to Karachi.

Global warming gases are on the increase. This means there will be accelerated rise in sea level. The sea level rise (SLR), combined with worsening storm surge, threatens to harm people, property, and ecosystems in coastal communities.

Figuring out future SLR is a complex process involving ocean currents, sea depths and gravitational effects, which will tend to pool up the water in some areas more than others, and even weather patterns (wind direction).

There are large uncertainties in sea level projections. According to some researchers, the SLR projection for Karachi for 95 percentile is 2.6 metres (8.5 feet) by 2100, relative to the level in 2000. SLR of about two meters is expected to submerge an area of about 7,500 sq km in the Indus Delta. In other words, both Bundal and Buddo Islands will stand submerged under seawater.

Impacts of development

The images and videos of the islands, available on the social media, clearly show that the mangroves and small streams crosscut the islands, making them unviable for development.

Assuming that the development, somehow, does takes place, then the question is: what are the impacts of development; and, since the islands are, probably, out of bounds of Sepa, who will control the environmental pollution?

Small islands have unique, interrelated characteristics. These include high populated density, fragile ecosystems, isolation from the mainland. These characteristics make them more vulnerable to environmental degradation. Small islands also face challenges like illicit exploitation of natural resources, climate-related natural disasters, rising water temperatures, storm surges and ocean acidification.

In water engineering, it is an established fact that the more the raw water source is polluted, the higher will be the operation and maintenance cost of the water treatment plant. Human activities will degrade the surrounding seawater quality.

The increase in global warming is causing intensification of extreme events and external shocks. It is a generally accepted view that climate change will disproportionately impact the islands. Since the development on Bundal and Buddo islands, should it take place, will consist primarily of high-rise buildings, the ‘heat islands’ so formed, together with the heatwaves, will make life on the islands inhospitable.

— The writer has a master’s degree in water and waste-water engineering from the Asian Institute of Technology, Bangkok.

Published in Dawn, November 19th, 2020