COASTAL EROSION

What is coastal erosion?

Beach erosion is defined by the actual removal of sand from a beach to deeper water offshore or alongshore into inlets, tidal shoals, and bays. Such erosion can result from any number of factors, including the simple inundation of the land by rising sea levels resulting from the melting of the polar ice caps.

Contributing factors

Sea level rise causes an increase in coastal erosion and the human response will be critical. If we choose to build hard structures in an attempt to keep the shoreline position stable, we will lose the beach area due to scour. If we let the shoreline migrate naturally, we can expect to see erosion rates increase, especially in regions of the coast that are already dealing with starved sediment budgets and rapid shoreline migration. Increases in storm frequency and intensity in the future will also cause increased coastal erosion

Climate change

As global temperatures continue to rise, driven by emissions of heat-trapping greenhouse gases, melting ice will raise sea levels and extreme weather events are expected to become more frequent and intensify, battering vulnerable coastlines around the world.

Seawalls

Private property owners often construct seawalls to stop the natural erosion of sand close to their property. However seawalls do more than steal sandy beaches, they also have major ecological, economic, recreational, and cultural impacts. Studies have shown that seawalls greatly impact the biodiversity of beaches because the lack of sandy areas makes it challenging for coastal species to nest, breed, and feed. For example, a study found that beaches with seawalls had significantly fewer and smaller intertidal species, three times fewer shorebirds, and four to seven times fewer gulls and other birds than unarmored beaches.

Impacts

In the United States, coastal erosion is responsible for roughly $500 million per year in coastal property loss, including damage to structures and loss of land. To mitigate coastal erosion, the federal government spends an average of $150 million every year on beach nourishment and other shoreline erosion control measures.1 In addition to beach erosion, more than 80,000 acres of coastal wetlands are lost annually—the equivalent of seven football fields disappearing every hour of every day.2 The aggregate result is that the United States lost an area of wetlands larger than the state of Rhode Island between 1998 and 2009.3

Louisiana

Louisiana has the highest rate of wetlands loss in the Country, with the State accounting for 80 percent of the nation’s coastal wetland loss.[1] In total, the USGS estimates that Louisiana has lost approximately 1,900 square miles of its coast since 1932. Within the past 100 years, Louisiana's barrier islands have decreased in area by more than 40 percent, and some islands have lost more than 75 percent of their land area. If these loss rates continue, several of the barriers are expected to erode entirely within the next three decades. Their disappearance will contribute to further loss and deterioration of wetlands and back-barrier estuaries and increase the risk to infrastructure.

Monterey

Rain, wind, and waves along the coast of Monterey County induce large amounts of erosion, especially during winter storms. In particular, El Niño events have produced large waves that have stripped volumes of sand from Monterey Bay, leaving the beaches, dunes, and cliffs exposed to high tides and wave attacks. As a result of the 1982–1983 El Niño events, approximately 20 to 40 feet of the marine terraces by Scenic Drive in Carmel fell into the sea. In the 1997–1998 El Niño winter storm event, a Light Detection and Ranging survey revealed that maximum dune erosion occurred in the vicinity of Fort Ord (43-foot retreat) and the city of Marina (50-foot retreat). During both El Niño events, several extremely steep cliffs (100 percent slope) near Big Sur failed as a result of increased wave attacks. In addition to winter storms, earthquakes have caused the Monterey cliffs to erode. October 17, 1989, Loma Prieta Earthquake produced several isolated cliff failures throughout the coastal county.

The solution

Beach Nourishment

Many states have shifted toward non-structural shoreline stabilization techniques. Unlike structural projects, nature-based or "green infrastructure" protection measures enhance the natural ability of shorelines to absorb and dissipate storm energy without interfering with natural coastal processes. One common strategy for dealing with coastal erosion is beach nourishment—placing additional sand on a beach to serve as a buffer against erosion or to enhance the recreational value of the beach. However, beach nourishment has also become a controversial shore protection measure, in part because it has the potential to adversely impact a variety of natural resources.

Coastal restoration

Even with the implementation of coastal shoreline erosion and risk reduction measures, residual risk remains. Some areas are constantly in danger during severe storms. For some regions of the country, the more intense storms are predicted to increase in strength and frequency as the climate continues to change, though the overall frequency of all storms may decrease. In some cases, the only way to prevent structures from causing harm may be to remove them entirely. After the structure has been removed, communities usually dedicate the land to public open space or transfer it to land trusts for protection. Coastal restoration projects can be highly cost-effective for communities. Benefits of returning land to its undeveloped state include buffering storm surges, safeguarding coastal homes and businesses, sequestering carbon and other pollutants, creating nursery habitat for commercially and recreationally important fish species, and restoring open space and wildlife that support recreation, tourism, and the culture of coastal communities.

Coastal health

California

The ocean drives global systems that make the Earth habitable for humankind. Our rainwater, drinking water, weather, climate, coastlines, much of our food, and even the oxygen in the air we breathe, are all ultimately provided and regulated by the sea. Careful management of this essential global resource is a key feature of a sustainable future. However, at the current time, there is a continuous deterioration of coastal waters owing to pollution, and ocean acidification is having an adversarial effect on the functioning of ecosystems and biodiversity.

California borders the Pacific Ocean, which makes up almost half of the world’s ocean area and is home to much of the planet’s biodiversity. Just offshore, the California Current is the feeding ground for billions of fish, mammals, and birds. These consistently cool waters help create our state’s mild, welcoming climate and support a thriving economy within the Golden State.

Challenges facing California's ocean ecosystems

1. Habitat and species loss

California’s coasts look different than they did 100 years ago. The state has lost about 90% of its coastal wetlands, mostly due to coastal development. Coastal wetlands, also known as estuaries, serve as nurseries for many ocean animals and provide critical habitats for numerous endangered and threatened species. They also protect our communities from floods, improve water quality, and reduce the impacts of climate change by sequestering carbon dioxide.

2. Offshore oil and gas development

The sustainable use of our ocean is the lifeblood of coastal communities. Offshore oil drilling and related activities put wildlife, jobs, and regional economies at unnecessary risk. Potential impacts of an oil spill are both immediate—killing and injuring countless fish, birds, and marine mammals—and long-lasting. Ecosystems contaminated by oil may take decades to recover.

3. Climate change

The global ocean is becoming warmer, more acidic, and oxygen-depleted. When we burn fossil fuels such as coal, oil, and natural gas, they emit excess carbon dioxide and other gases into our ocean and atmosphere. These gases act like a heat-trapping blanket around our planet, increasing global temperatures and disrupting our climate.

4. Plastic and other ocean pollution

Sixty-five percent of Californians live along the coast. But even for inland communities, chemicals, plastic and other waste eventually make their way to the ocean, traveling by wind and through freshwater sources like streams, rivers, and groundwater. This pollution harms ocean ecosystems and degrades water quality.

5. Unsustainable fishing

Unsustainable fishing, including certain gear types, high levels of catch and bycatch undermine the health of fish stocks, disrupt sensitive species and damage habitat.

The solution:

When visiting beaches it is necessary to not disturb the coastal environment. Along with behaving responsibly like not littering, leaving behind food items, etc it is important to keep in mind the sensitive marine life found there. Here are a few things to keep in mind:

Avoid approaching areas (sea caves, offshore rocks, cliffs, and beaches) with birds, seals, and sea lions that are roosting, nesting, or pupping. Look ahead and give animals a 100-yard clearance if possible. Be alert for birds that you may not be able to see around guano-covered rocks and pinnipeds hauled out on secluded beaches.

Seabirds and shorebirds are disturbed easily and may knock their eggs out of or abandon their nests if they are flushed suddenly. Adult birds will stay away from the nest while people are in the area. The eggs or chicks may overheat in the sun without parental protection. Gulls and ravens are less shy of people and will take advantage of a disturbance to steal eggs and chicks. Entire colonies have been lost this way.

Pupping harbor seals, sea lions, and other pinnipeds are also sensitive to any type of human disturbance and may abandon their pups. Be careful not to disturb seal pups that appear stranded on beaches. These pups are being weaned by their mothers. In addition, all of these animals are easily disturbed when resting or preening on rocks or secluded beaches at the water's edge. Rest periods are important to their energy budget. Approach new territory slowly and quietly. If you see animals close by, quietly move away. There may be more animals than you first see.

It is recommended that visitors avoid sea caves, including dry caves behind beaches, during the spring and summer when seabirds are nesting.

Entering caves and/or making loud noises in these areas may cause seabirds to abandon their nests. Pelagic cormorants nest on tiny ledges of sea cliffs and just inside the mouths of caves. Xantus's murrelets, pigeon guillemots, and ashy storm-petrels nest in crevices, ledges, and under rocks and debris inside caves. Many seabirds leave their nests alone while feeding, so even if birds are not present, a misplaced step could crush an egg or chick by moving a loose rock. Bats also hibernate in some of the dry sea caves and waking them can cause a fatal depletion of energy reserves.

There may be resting birds and pinnipeds in caves and on offshore rocks even after the breeding season. Under federal law it is illegal to disturb and/or harm these animals. Be cautious of pinnipeds resting on rocks or beaches in the backs of caves. Startling a pinniped that you can't see in the dark could be hazardous for you as well.

Avoid using artificial light when viewing wildlife and at anytime while in sea caves.

Birds, pinnipeds, bats, and other animals are all easily disturbed by artificial light.

In order to be rewarded with displays of interesting natural behavior, never chase any animals and do not try to see how close you can approach them.

If an animal starts to look alarmed (appears agitated or starts watching you), then you are too close. Even though it may not show obvious agitation, being too close can cause severe stress. Sit calmly at a safe distance. Let the animal's natural curiosity take over and it may approach you. Let seabirds, pinnipeds, foxes, and other animals adjust to your presence and you will be rewarded with displays of exciting natural behavior. For your safety as well as theirs, do not approach sick or injured animals. Alert a ranger or a wildlife rehabilitation center.

Avoid disturbance of nesting and pupping wildlife and take advantage of the islands' best weather by kayaking during September and October.

Most seabirds, shorebirds and pinnipeds have completed their reproductive cycles by this time. In addition, calm seas and light wind are common during these months.

Microplastic

What is Microplastic?

Microplastics are small plastic pieces less than five millimeters long which can be harmful to our ocean and aquatic life. There are two categories of microplastics: primary and secondary. Primary microplastics are tiny particles designed for commercial use, such as cosmetics, as well as microfibers shed from clothing and other textiles, such as fishing nets. Secondary microplastics are particles that result from the breakdown of larger plastic items, such as water bottles. This breakdown is caused by exposure to environmental factors, mainly the sun’s radiation and ocean waves.

Causes and contributing factors

According to the research, anywhere between 9,000 and 32,000 tonnes of microplastics end up in our waterways each year, outstripping the larger sources by some distance. This unacceptable level of pollution is caused primarily by four different causes, which are as follows:

Vehicle tyres

Tyre abrasion is responsible for creating up to 68,000 tonnes of microplastic pollution each year, between 7,000 and 19,000 of which end up in UK waterways.

Clothing

Tiny synthetic fibres in our clothing can be released into the waste drainage systems of washing machines when we wash our clothes, generating between 2,300 and 5,900 tonnes of microplastic contamination each year. As much as 2,900 tonnes of that amount is capable of bypassing wastewater treatment filters and ending up in our waterways.

Plastic pellets

Used in the manufacture of a variety of different plastic items, plastic pellets can contribute as much as 5,900 tonnes of microplastic waste to UK waterways per annum.

External paint

Inclement weather and natural flaking means that the paint used on buildings and road markings can contribute between 1,400 and 3,700 tonnes of microplastic pollution to our waterways every year.

Impact

The problem with microplastics is that—like plastic items of any size—they do not readily break down into harmless molecules. Plastics can take hundreds or thousands of years to decompose—and in the meantime, wreak havoc on the environment. On beaches, microplastics are visible as tiny multicolored plastic bits in sand. In the oceans, microplastic pollution is often consumed by marine animals. Microplastics have been detected in marine organisms from plankton to whales, in commercial seafood, and even in drinking water. Living organisms tangled in microplastics. A sample of water collected off the coast of Hawaii shows how intertwined microplastics are in the daily lives of marine animals.

Solution: How can we help?

While the problem of plastic in the ocean may seem overwhelming, it is solvable. Each one of us can make a difference by using less single-use plastic in our everyday lives. We can also use our voices — and wallets — to support policies and businesses that are advancing solutions to the ocean plastic problem.

Support policies to reduce single-use plastic

• By supporting policies to reduce plastic, you are telling policymakers that ocean health is important to you.
• You can also urge your elected officials to improve waste management systems, including recycling.

Cut back on single-use plastic

• Use reusable coffee cups and shopping bags instead of single-use ones. Reusable silicone bags and other durable containers can replace single-use plastic sandwich bags.
• When you shop, consider buying some grocery items in bulk by filling your own containers.
• Choose products with less plastic packaging and support businesses that are working to reduce their plastic waste.

Recycle properly

• Whenever possible, choose products with recycled plastic content over those made with virgin plastic.
• Support improvements to recycling infrastructure in your community. If you don’t have a curbside recycling service, ask for it!
• And before you toss your plastic waste in the blue bin, take a second to make sure it is actually recyclable where you live.

Are compostable plastic products a better choice?

• Make sure you know how to properly dispose of the product — for instance, certified compostable products are designed to break down under certain conditions (heat and pressure) at industrial composting facilities, but not necessarily in the ocean, landfill or your backyard composting pile.
• If you live in an area with industrial composting services and are able to dispose of certified compostable products in compost waste bins, then these products are good alternatives to non-compostable plastic.
• If your community doesn’t offer composting services, you can step up to advocate for them.

Get involved

• Help keep plastic out of the ocean and other waterways by participating in local trash cleanups.
• Reduce plastic use. The more we can prevent plastic from becoming waste in the first place, the less we’ll have to clean up later, so tackling this issue at the source has big benefits.
• Speak up about ocean plastic pollution. The more we talk about it and share ideas, the easier it is to reduce plastic waste, and the more change will happen.