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Dredge elsewhere! Environmental damage to Portland Bight outweighs economic benefits

Published:Sunday | September 8, 2013 | 9:00 AM
Portland Bight, in southern Jamaica, was designated a Wetland of International Importance in 2006. - File

Howard Chin, Guest Columnist

Anyone who says that the 'development' of the Portland Bight is a 'no-brainer' is likely to be the person who has no brain. Understanding is the key to all of this.

Roger Clarke speaks of "food security" and says, rightly, that we have to produce a larger proportion of the food that we consume instead of importing it, using foreign exchange, which we are not earning. Part of that 'production' is our fisheries, which have seen extensive overfishing and precipitous decline of the catch.

Remember when the Kingston Harbour was dredged years ago? I've been fishing at Port Royal Point from the 1970s and the fishermen have told me that the snappers that used to concentrate near the dredged-out reef were gone, and that was years after.

Both locally and in other countries, the beneficial effect of fish sanctuaries is well documented. It is apparent, also, that local fishermen have seen the successful results of fish sanctuaries in other countries.

Small fish don't need protection to grow to a size where we relish eating them, as the Jamaica Labour Party's (JLP) Warmington, the People's National Party's (PNP) Phillips, Hylton, and others seem to believe. They magically go from eggs to eating size. The reality is that everything eats the hatchlings, even the baby barracudas and jacks, more so in open, deep water.

Seagrass beds, mangrove roots, gravel beds and shallow water allow the baby fish, shrimp, etc. to hide and have a moderate chance of avoiding being eaten by adult snappers, jacks, tarpon, grunts, snook, and many others. I have seen on Barry Street, fish vendors in the past, selling baby snook as small as 20cm (eight inches) long, netted from Dawkins Pond with its mangroves and seagrass beds, now mostly silted up by the blockage of the approaches to the causeway.

Where do the better-looking shrimp being sold by the Indian lady on South Avenue come from? I've asked, and was told, the seagrass beds of Old Harbour, which is in the Portland Bight. In Kingston, with the Kingston Harbour as badly polluted as it is, can you imagine having to get your shrimp from as far as Black River? You couldn't afford them because of the distance they'd have to be transported, and the shrimp vendors would go broke. However, do you think we're the only ones eating the shrimp? Smaller shrimp form the part of the 'baby food' for fish. Tasty predatory fish that leave and migrate east and west along the coast.

Last year, I collected more than 200 seedlings from the mangroves growing around the small jetty, a little past the Plumb Point Lighthouse on the harbour side, to try to re-establish at least a couple of the previous spots where they used to be along the raised Palisadoes roadway. They failed to thrive and then died, most likely because of the lack of sufficient silt to nourish them.

Saying that they will replant mangroves, re-establish reefs, etc. to replace those destroyed, is not so simple.


Ever hear of the term Panamax? It's a shipping term denoting the maximum size of a ship able to pass through the locks of the Panama Canal. It is 294.13m (965 feet) long, by 32.31m (106 feet) wide, by 12.04m (42.2 feet) draught (depth) capable of carrying 5,000 TEUs or 20-foot-long shipping containers. That's about to be old news.

What about New Panamax? That's the maximum-size ship capable of using the upgraded Panama Canal, and it's much bigger, and is defined as 366m (1,200 feet) long, 49m (160.7 feet) wide, 15.2m (49.9 feet) draught, and capable of carrying 12,000 TEUs (another source says 13,000 TEUs), displacing about 120,000 tons. That's really big.

However, I bet you have never heard of the term Nicamax. Well, I just made it up, but it will be the same as Wikipedia's Chinamax. The proposed Nicaraguan Canal is projected to pass 400,000-ton displacement ships, and, with a reported canal depth of 27.6m (91 feet), assuming a 10-foot clearance from the bottom of the canal, the ships that can transit should have a draught of about 80 feet.

Already, ships are being built to Chinamax size. Brazil is reported to have ordered 35 VLOCs (Very Large Ore Carriers) with 380,000- to 400,000-ton displacement. A container ship with the same ratio of TEUs to displacement that would correspond to a mind-boggling 38,000 to 40,000 TEUs. Talk of the economies of scale possible! That's why the Chinese need the reported 3,000 acres for the trans-shipment port.

All the recent aircraft carriers of the United States Navy, used for force projection, have all been built to Post- or New Panamax size, and, just coincidentally, the rights to, I am sure, transit the upgraded Panama Canal. When the Chinese build the Nicaraguan Canal, wouldn't they have negotiated the rights for passage of Chinese warships, and Chinamax-spec commercial ships, which would not be able to, or allowed to transit the upgraded Panama Canal? An interesting thought.

As well, it would draw business away from the Panama Canal. After all, why wait in a queue to transit when there's a new canal to the north that would have locks capable of accommodating two moderate-size ships in its locks at a time?

Proposed dredging

Now, what is to be the extent, and depth, of the proposed dredging of the Portland Bight Protected Area? The Jamaica Environment Trust and the others concerned about it don't seem to know. Want to bet it would allow Chinamax-class ships with a requirement of about 27.5m (90ft) depth as I would deduce?

What about the currents in the Bight? Wouldn't they be changed by the deep ship channel, berthing areas, and huge turning basin? Because the bigger the ship, the more it takes to turn. I'd also bet that some within the PNP know from the Chinese what the extent of the damage to the protected area would be, and the JLP just seems to be overall ignorant. If they don't, Jamaicans are being taken for suckers.

Run-off from dredging

There's also the simple matter of runoff. The proposed 3,000-acre (4.7 square-mile) port facilities would, of course, be mostly paved, and pavement has no capability to absorb or even delay the flow of rainfall on its way to the sea. Consider a major rainfall event, not a maximum as may occur in a hurricane, of about 10cm/hr (4in/hour). This would translate into approximately 1.2 million cubic metres/hour (271 million imperial gallons/hour) or a 3/4 Hermitage reservoir/hour into the sea. Any fish or shrimp not able to swim fast enough, and corals that cannot survive in fresh water, would die.

We should consider elsewhere. The Portland Bight was created a sanctuary by both the PNP and the JLP after careful thought. Should they now destroy it after so little thought? Fools!

Beware of the man with the plan when you have no plan.

Howard Chin, MJIE, PE, is a member of the Jamaica Institution of Engineers. Email feedback to and