Life's a beach: Nature-based solutions for coastal protection

Nature based solutions, including coral reef restoration and artificial coral reefs, protect one of tourism’s primary draws – the beach. 

White sandy beaches and year-round summer temperatures attract tens of millions of tourists each year to destinations like the Caribbean. Tourism remains a vital source of economic development for tourist hotspots. Even in countries with a colder climate, where beaches don’t attract international acclaim, they are often places of community gathering and recreation. 

The beach is an attraction in and of itself and, at the same time, provides coastal protection for communities and infrastructure from erosion and in-land flood risk. However, beaches themselves are prone to degradation by extreme weather events (such as hurricanes) and daily tidal activity, thereby reducing the beaches aesthetic appeal and capacity for coastal protection. Maintaining beach resilience should, therefore, be an important priority for coastal and tourism-driven communities. 

Various technologies have been deployed world-wide for beach protection, with the ‘quick and dirty’ solution being sand re-nourishment projects. In the U.S. the government has funded to the order of US$ 9 billion for such projects, which entail the dumping sand in regions where beaches have eroded. This option is costly and temporary and does not offer a sustainable solution to a long-term problem that is likely to worsen with climate change. Construction of hard and semi-hard infrastructure (such as sea-walls, groynes and breakwaters) have also been deployed globally and in certain instances have provided important coastal protection services. However, they carry the possibility of risk transfer to adjacent non-protected areas and are considered an eye-sore in scenic and tourist areas.

In recent years, natural and hybrid approaches to beach erosion and sand loss have been piloted. These Nature-based Solution (NbS) include coral reef restoration, artificial coral reef construction, natural engineering projects, and sand and dune restoration. NbS can protect against beach erosion, while delivering a series of co-benefits, some of which may generate income streams. For example, coral reefs can dissipate up to 97% of incident wave energy and provide revenue generating opportunities associated with snorkeling, diving, fishing, aquarium trade and more. There is no one-size-fits all solution to the site-specific complexity of beach erosion, however several innovative examples illustrate how NbS can be leveraged to offer coastal protection services. 

What are Nature Based Solutions? (NbS)

There are an abundance of NbS definitions, and no universally accepted one. In short, NBS are those that that are designed, inspired or supported by nature. Here’s one definition from the European Commission’s Directorate General for Research and Innovation: NbS are solutions “which aim to help societies address a variety of environmental, social and economic challenges in sustainable ways, including actions which are inspired by, supported by or copied from nature. NbS use the features and complex system processes of nature, such as its ability to store carbon and regulate water flow, in order to achieve desired outcomes, such as reduced disaster risk, improved human well-being and socially inclusive green growth”.

To get a better understanding of what this entails, it is helpful to look at examples from practice around the world.

Now Jade Hotel, Mayan Riviera Mexico, artificial coral reef

The Now Jade Riviera Cancún Resort and Spa (“Now Jade”) is located in the popular tourist destination of Puerto Morelos, Mexico on the Mayan Riviera, in close proximity to the Mesoamerican reef. In 2008, Now Jade embarked on a long-term beach restoration program focused on the construction of two modular artificial reefs and future restoration of the sand-dune ecosystem.

Prior to 2007, the Puerto Morels beach experienced a pattern of sand accretion in summer months and retreat during winter months, with sufficient year-round sand for tourist activities. In 2007, the coast was hit by hurricane-induced waves which caused high volumes of sand to travel from north to south. An adjacent breakwater stopped the longitudinal currents and induced chronic erosion of the beach. In 2010, with the beach narrowing with on-going erosion, it was decided that beach resilience efforts were necessary to regenerate the sand.

Several options for coastal protection were considered including hard structures. However, tourist-specific considerations required that the structure be not only aesthetic, but also ecologically friendly. An artificial coral reef was selected for the following reasons: reefs are effective at wave energy dissipation, the proximity of the Mesoamerican Reef would facilitate species colonization, the dynamics of sand transport had already been negatively affected by the existing breakwater and the artificial reef would bolster the conservation and tourist appeal of the area.

Following a series of site-specific assessments and laboratory tests, the reefs, made out of pre-fabricated concrete elements, were constructed 120 meters offshore. Five years after construction, an assessment showed that the reefs have contributed to beach recovery, with a natural growth and retreat cycle, and attracted fish and coral colonies from the nearby Mesoamerican Reef. An influx of Sargassum seaweed in 2015 created a temporary decline in reef colonization, however since then the reef has been recovering biological richness in the absence of human intervention.

Mayacoba Resorts: Coastal restoration project

Mayakoba is home to four luxury resorts located on the Mayan Riviera: Andaz Mayakoba, RoseWood Mayakoba, Fairmont Mayakoba and Banyan Tree Mayakoba. As with other beaches in the region, Mayakoba has experienced significant sand loss to the order of 15 feet per year since 2005, spurred by two hurricane events. This presents significant challenges for resorts, which off the primary attraction of long, white sandy beaches for guest enjoyment. Furthermore, beach erosion could negatively impact 150 acres of protected mangroves surrounding the resorts, which are home to alligators, turtles, and various bird species, and even further undermine the resorts coastal resiliency. 

Mayakoba, in consortium with local organizations, embarked on reef restoration efforts to enhance coastal protection services and biodiversity. Scientists transplanted fragments from a coral nursey onto a concrete grid on the ocean floor on the Mayakoba coast. The artificial reef is expected to connect with the nearby existing natural reef to form a self-sustaining colony, capable of providing coastal protection services. 

As of spring 2018, initial trials were performing well with the Elkhorn coral thriving in the concrete barriers. It is expected to take two years for the coral to mature into a strong colony and four years for the coral to start reproducing. Once mature, the reef is expected to help protect Mayakoba beaches from erosion, and attract fish and marine life to create a more desirable attraction for snorkelers and divers.

Mayacoba’s Fairmont even offers a ‘Coral Reef Restoration Package’ where guests can participate in restoration efforts as a part of their stay. Twenty-five percent of revenues from this package are redirected to fund reef restoration efforts. The resort is able to capture an additional revenue stream through this package, offering an additional economic incentive for investment in coastal restoration. 

There are a series of challenges that could compromise the corals restoration efforts, and the services they provide. This includes coral bleaching driven by increased sea surface temperatures and sunlight exposure, sargassum influx, extreme events (i.e. hurricanes that cause structural damage to the reef, and industrial run-off). The inability to effectively regulate the anthropogenic activities (i.e. greenhouse gas emissions, and agricultural runoff) creates a challenge for the successful revival of coral reefs. 

Netherland’s Sand Motor

The Dutch have long been striving to protect their low-lying country from sea level rise and coastal erosion. In the past, the sand dunes on the Dutch peninsula were replenished every 5 years, via sand shipment from the North Sea. However, the Dutch wanted to pilot a lasting solution that would allow the country’s southwest beaches to regenerate on their own, a popular kite-surfing destination and recreational area for the urban population.

The creation of the Sand Motor, a large artificial hook shaped peninsula, changed the dynamics of the winds, waves and currents to gradually spread sand along the coast and form a new dune landscape and wider beach. The sand motor was initially constructed with 21.5 million cubic meters spread across an area of 128 hectares, and natural processes are expected to add an additional 35 hectares to the coast over a 10 km stretch in the next 20 years. By depositing a large volume of sand at once, the sand motor avoids repeated disruption to the seabed.

Preliminary 5-year results of the Sand Motor show that it is acting mostly as expected, supplying sand to a five kilometer stretch of beach, with 1.5 million cubic meters of sand moved to the north, and nearly 1 million cubic meters moved to the south. Only dune growth in the coastal area near the Sand Motor is progressing slower than expected. The expansion of the beach has provided a greater area for community recreation and outdoor activities, and has become somewhat of a tourist attraction in itself. Long-term analysis of the Sand Motor (20 years) will ultimately show whether it is a viable solution, and can be reproduced as a coastal management strategy in other countries.

Please see this publication for further information on the Sand Motor.

Challenges of these projects and steps forward

These case studies provide insight into a variety of NbS that can be deployed for coastal protection. The solutions are not driven by an ecological imperative, but rather a coastal protection one that delivers ecological co-benefits. This distinction is important as it puts NbS on the same playing field as engineered solutions. A solution that effectively fulfills the coastal protection imperative in a cost-effective way, while delivering a series of co-benefits (that traditional infrastructure does not) will generate win-win results for businesses, communities and tourists.