And there are many, many other large towns and cities around the world that have grown up around natural harbours.
From natural harbour to megacity
While people have lived in these areas for thousands of years, the enormous cities and megacities that have grown over the past 100 years have - unsurprisingly - quickly destroyed natural marine and coastal habitats.
The construction of general infrastructure such as roads, homes, shops, factories, airports, and ports completely replaces natural habitats. In addition, estuaries, deltas, and their rivers are often dredged and deepened to cope with increased shipping.
Added to this are impacts such as increased erosion due to coastal development, increased pollution, and increased boat traffic - all of which lead to further habitat loss and put increased pressure on marine species.
Hong Kong, Singapore, Manila, and Honolulu, for example, once had thriving coral reefs. But these have been destroyed by human pressures, largely from coastal development.
Similarly, the once extensive Posidonia seagrass meadows of the Mediterranean are now endangered, and have all but disappeared along the densely inhabited north-west coast thanks to construction works, pollution, and damaging fishing and boating activities.
Dams, dykes, and other developments
In many places, dams and dykes have been constructed to protect coastal towns, cities, and farmland from storm surges and high tides. This is particularly the case for reclaimed or drained land. However, these constructions destroy natural coastal dynamics and functions, as well as rare habitats like salt marshes.
Other coastal developments can also harm sensitive marine habitats and species. For example, while WWF promotes wind power, we recognize that poorly planned wind farms may affect the migration, resting, and breeding of some bird species. In addition, poorly planned wind farms may increase shipping risks.
