The EPA estimates that every year up to 3.5 million Americans get sick from contact with beaches that have been contaminated with raw sewage from overflowing local drainage systems.
Human civilization developed naturally around the ocean. Over the years, seashore houses grew into towering high-rises and small beach towns turned into booming population hubs. Today, one out of every two people lives within 60 kilometers of a coast, and more than 61% of the world’s total GNP comes from regions within 100 kilometers of the ocean.
The extensive overdevelopment of Earth’s shorelines coupled with the concentration of harmful human activities has caused adjacent marine ecosystems to suffer disproportionately. Agricultural, industrial, urban, and commercial development has degraded and destroyed key marine habitats around the world.
When human populations and developments expanded worldwide, the coastal landscape and connected drainage basins were significantly altered, increasing the volume of land-based pollution. Since trees and vegetation stabilize shorelines and filter pollutants, deforestation for agricultural, residential, or industrial settlements results in increased sediment, nutrient, and chemical runoff into coastal habitats. Sedimentation suffocates coral reefs, plankton, and aquatic vegetation, which need sunlight to survive. While the influx of sewage and land-based pollutants poisons the local food web and changes water chemistry, ultimately making the water inhospitable to most sea life. For instance, the nations of Southeast Asia, the Caribbean, and the Pacific are known to discharge 80-90% of their untreated sewage into the ocean. Studies have shown that beach sand, even in the U.S., contains 100 times more fecal matter than adjacent, contaminated seawater.
Coastal construction projects, though focused on land, often negatively affect adjacent ocean ecosystems. Dredging, land filling, the building of piers and shipping channels, and beach renourishment projects can quickly destroy entire coral colonies and beach habitats, undermining the chances of survival for all dependent fish, bird, mammal, and turtle species.
Artificial light and noise pollution more gradually degrade marine ecosystems. For instance, baby sea turtles, which follow the moonlight back to the ocean, are being led away from the water’s safety and into danger by lighting from nearby developments. Noise from boat traffic and beach-goers is proving deafening to dolphins, whales, and even coral larvae, all which depend on sound to communicate, hunt, and orient themselves.
Built in reaction to erosion and storm surges, coastal armoring structures inadvertently degrade essential coastal habitats. Seawalls and jetties prevent nutrient flow to dune ecosystems, ultimately deteriorating vital beach and off-shore ecosystems. Healthy beach vegetation, mangroves, and marshes act as extremely effective natural wave barriers. 15 feet of marsh can absorb 50% of all incoming wave energy, while mangroves can reduce over 66% of wave height—slowing erosion and reducing flood risk. Unfortunately, more and more coastlines are being covered with protective concrete walls. In the U.S. alone, over 14,000 miles of natural coastline have been covered by concrete walls— with an estimated 33% hardened with man-made structures by 2100. Climate change and human population growth are only going to exacerbate erosion, sedimentation, and pollution run-off. Unsustainable and unregulated development is directly and indirectly destroying vital marine ecosystems— inadvertently making coastal populations even more vulnerable to climate change impacts.