Dredging Plan Threatens Durban's Marine & Bird Ecology

Durban's Huge Harbour Expansion Threatens Sensitive Estuarine Ecology

By Tony Carnie

PLANS to dredge huge volumes of sand off the Durban coastline to allow further expansion of the harbour have rung alarm bells among local fishermen and ecologists.

Transnet has announced proposals to suction dredge up to 4.5 million cubic metres of sand from the old dredging mounds south of Durban harbour and use this material to expand container handling and berthing facilities, to lengthen North Pier and build a new passenger terminal.

Despite being the largest shipping container port in the country, Durban Bay remains an important nursery for a wide range of juvenile sea fish and also home to a wide range of marine and estuarine creatures and birds, including Fish Eagles, ospreys and Goliath Herons.

Several ecologists are concerned that any further infilling of the harbour’s shallow water surface areas could threaten the bay’s ecological health, while local paddleski fisherman Johnny Vassilaros said he was worried that turbidity (clouds of fine mud and sediments) from the dredging and dumping could smother fish and marine life off Vetch’s reef, as well as inside the main harbour.

Vassilaros said that sand previously dumped to replenish the beaches at Vetch’s and uShaka often produced plumes of dirty water.

Massive Environmental Concerns

Durban estuarine ecologist Nicky Forbes said she doubted that the dredge material would have fine sediments. It was more likely to contain larger and much coarser sand.

Instead, the biggest concern was that further incremental infilling of shallow water areas could destroy some of the richest feeding areas for birds and fish.

“It is these small remaining shallow water environments, mud banks and soft edges of the Durban Bay that contain all the worms, prawns, crabs and other small invertebrates that form the basis of the food chain for marine and bird life.

“They are absolutely critical. We run the risk of losing Durban harbour as a functional estuarine system if it is pushed past a certain ecological tipping point.” Environmental consultants acting for Transnet sent out a notice last week giving brief details about the plan and invited interested groups to register their concerns as part of a mandatory environmental impact assessment process.

Nemai Consulting says in a background information document that the sand would come from two old dredge mounds to the east of the main Durban harbour mouth. The two mounds were dredge material from the harbour during the late 1800s and early 1900s.

According to Nemai, Transnet expects container traffic to grow from the current volume of 2.6 million TEU (20ft equivalent units) annually to around 4.2 million TEU along the Durban-Gauteng corridor over the next 10 years.

While Durban harbour had capacity for 3.4 million TEU, the existing container handling facilities needed to be optimised and expanded to prepare for future growth.

This would involve reconfiguring the existing Durban Container Terminal and expansion of Pier 1.

Other major expansion projects include deepening and lengthening the North Quay, reconstruction of shipping berths at Island View and Maydon Wharf and the development of a new dedicated passenger terminal.

Nemai said at least three specialist studies were needed. These included a marine assessment, a maritime archaeology impact assessment and a sand-winning site wave study.

For information, contact Vanessa Stippel of Nemai Consulting at 011 781 1730 or

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