Ports and marinas

Picture courtesy of NOAA.

Harbour construction and reclamation accounts for substantial habitat loss, particularly in estuaries and along the coastal zone. Construction may lead to changes in water currents and circulation, turbidity and sediment load, which in turn will affect benthic communities.

A study looking at mapping the gulf of Porto Vecchio, Corsica, revealed that P. oceania seagrasses meadows were almost entirely absent from the inner basin. The bay floor appears to be covered by a layer of silt, resulting from dredging work dating back to 1970s, which overlays coarse sand and dead seagrass matte. These port facilities seem to be the reason behind the close to total disappearance of P. oceania beds in parts of the gulf of Porto Vecchio.

Barbados: In the last few years the port of Bridgetown, has experienced significant increase in both cruise ship and cargo visits. Seeing as this increase is forecasted to continue, the government felt a need for updating and expanding berth and cruise ship facilities. Such work requires land reclamation for these purposes, extension of the breakwater to prevent northerly waves from entering the harbour, construction of berthing facilities alongside the breakwater to accommodate cruise ships, installation a second Gantry crane and dredging of the deep water harbour to accommodate large cruise ships. The planned expansion project will have considerable impact on surrounding habitats and water quality, some of which are likely to include:

• Smothering of surrounding coral communities due to increased sedimentation rates
• Loss of coral and fish communities as a result of land reclamation. Fish and corals will effectively be buried under dredged spoil material.
• Decreased water quality due to dredging and release of toxins from the deep water benthic environment.
Under pressure from the coastal zone management unit and the fisheries department the government agreed to pay for corals to be transplanted from the projected land reclamation area to a suitable site further along the coast and monitor their health over the course of a year.

Understanding the marine processes and the behaviour of coastal ecosystems are important to the successful implementation of port and marina projects. When such knowledge is not included in the design, significant adverse impacts are the result.