In Colombia, the impacts of climate change already have communities, strategic ecosystems and infrastructure on both coasts in trouble. According to the Ministerio de Ambiente (Ministry of the Environment), 30% of the Caribbean coast and 27% of the Pacific coast are at critical risk due to coastal erosion and rising sea levels. In just 17 years, the country could lose about 12,630 hectares of coastal land.
Human actions have made it more difficult for beaches to maintain their resilience, that ability to overcome disturbances, to adapt to stress and change without losing their functions. Some of the most extreme cases, according to the Institute of Marine and Coastal Research (Invemar) are found in the departments of Magdalena, Bolívar and Antioquia.
Although in Colombia there is the "Coastal Erosion Master Plan", published in 2017, its implementation has been a challenge, so the degradation taking place in these three instances is difficult to curb. According to the Ministry of Environment, "this is only a technical document, which gives some guidelines, but does not have a level of detail on what projects and actions could be implemented in the territory," says Ximena Rojas, spokesperson for the Ministry.
One of the major challenges, she points out, is to coordinate all the entities, institutions, authorities and governments that deal with the problem of coastal erosion, such as mayors' offices, risk and disaster units, among others. However, she states, "coastal erosion is a priority for the new government". By 2030, it is expected that 100% of the master plan will be updated, adopted and in the process of implementation.
We visited some places threatened by coastal erosion to find out how the beaches have been lost, how serious the problem is, how communities are being affected and what the authorities are doing to deal with it.
Monoculture and mangrove deforestation increase erosion in Punta Coquitos
Wave after wave, Punta Coquitos disappears. Where 35 years ago there was a road, a small wooden school, houses of several peasants, a lot of coconut palms and mangroves, today there is only water left.
"The sea has taken everything," says Joiber Berrío, one of the peasant leaders in the area. It also took some crosses, plaques, and a 20-meter pole that the inhabitants of Coquitos had placed on the seashore to remember that, on April 11, 1988, paramilitaries carried out a massacre in that place. “At that time the seashore was approximately more than a thousand meters outwards, towards the water,” says Joiber. "But all of that was eaten by erosion."
The sea, which with its force and current is gaining more and more land from the coast, threatens the inhabitants of Coquitos with not only the memories of the violent acts disappearing, but also their homes and several hectares of crops.
Los Coquitos is part of the village of Nueva Colonia, in Turbo, Antioquia. A land that, since the 1960s, was promoted as an axis of agro-industrial development in the country.
Everywhere you look, there are banana and plantain plantations. Its massive production and export has consolidated in this place one of the most important banana enclaves in the country. Sixty years of land transformation have also altered the behavior of the coast.
In the words of researcher Juan F. Blanco, who was part of the first high-resolution cartography of the Urabá antioqueño, coastal erosion is a natural process that occurs throughout the world, but has been worsening by human actions.
According to an investigation he carried out , the coastal erosion in the Urabá has been exacerbated by the high deforestation of mangroves, which serve as a protective barrier, and the monoculture banana plantations. Mangrove forests and floodplains were converted into cattle pastures and banana plantations over the years, since 1960s.
“Coquitos was a key place, because it was one of the most extensive and preserved mangroves. But investigations, cartography and satellite images —taken from Radar Sentinell 1 and the Instituto Geográfico Agustín Codazzi (Agustín Codazzi Geographic Institute)— made it possible to see that, since 1938, the mangroves of Urabá have been subjected to strong pressure and have deforestation rates higher than those of the rest of the Colombian Caribbean,” says researcher Blanco.
All these changes made Cayetano Sarmiento, a 90-year-old farmer from Coquitos, move his house more than five times in just 40 years. None of these moves were supported by authorities, risk management units or a risk and disaster management plan. Today, the communities demand from local, departmental and national authorities, the restoration and reforestation of mangroves on the beach, to promote coastal resilience and help contain the waves of the sea. “The armed conflict displaced us. And now the sea is also displacing us. But nobody says anything,” laments Gilberto Pérez, a resident of Coquitos.
Three years ago the Integral Program for the Monitoring and Mitigation of Coastal Erosion in the Antioquia Coast (PIMECLA) was created, an initiative in which the University of Antioquia and the Administrative Department of Risk Management of Antioquia (DAGRAN) participate. According to Vladimir Toro, leader of PIMECLA, different experimental actions have been carried out to mitigate this issue, which will enable, in the near future, the proposal of solutions in each municipality to address the effects of coastal erosion.
Among the adaptive solutions they contemplate are the revegetation of the land with native species and an improvement in the measurements of atmospheric and oceanic variables in the coast of Antioquia. They also succeeded in getting the current development plan of Antioquia to include coastal erosion as one of the department's natural threats. So far, however, none of the strategies have reached Punta Coquitos.
Salguero: the beach disappearing in Santa Marta due to unplanned development
The first thing to do before starting to read this case study is to take a look at the following image. In it, you will see a satellite photograph of a popular beach in the city of Santa Marta. You will notice that it is a very particular beach: in the north, where you can see a large brown stain, is the mouth of one of the rivers that comes down from the Sierra Nevada and that supplies the city with water, the Gaira River. If you look at the detail on the left, you will see that in the central part, there is an oddity: the beach seems to split in two.
Living in front of the sea is a fantasy that construction companies usually sell in Santa Marta. At the turn of the century, Playa Salguero, with only a few one or two-story houses, was not in their business plans, but in a matter of a decade it became a very attractive place to develop. Today its blocks are no longer pieces of wetland and tropical dry forest, but buildings with swimming pools, terraces, restaurants and a gym where some residents live and where people from other cities usually visit during the summer. Although sunrise a few steps from the sea is a luxury, Salguero has a drawback: little by little it is losing its beaches.
“I was born here, practically. I've been working here for over 40 years. This was a nice beach, but the sea came up against the buildings”, says Fabián Bermúdez. “I have been fishing for about 32 years and back then we had a large beach, where we could leave the boats. At this rate, we are going to end up putting them on the street because there isn't much of the beach left”, says Junior, while he prepares his net.
From an ecosystem perspective, preserved beaches play important roles in maintaining marine biodiversity. They provide particular habitats for a variety of plants and animals, they are breeding and nesting sites, and they also provide protection for residents living near the sea, acting as a buffer from winds, waves and storms. But they are also one of the most fragile coastal ecosystems.
In the last decade, Playa Salguero, with its 1.5 kilometers in length, has entered the list of critical points of coastal erosion identified by Invemar, the institute linked to the Ministerio de Ambiente (Ministry of the Environment) that carries out marine and coastal research. From their headquarters, a few blocks from the beach, they have produced several reports that try to explain what has happened in that place.
According to Camilo Botero, professor at the Universidad Sergio Arboleda, in addition to the elements typical of the natural phenomenon, there have been a series of errors caused by various responsible parties.
Salguero has been formed thanks to the contributions of sediments from the Gaira River. From the time it was born in the Sierra Nevada of Santa Marta, it has transported them to its mouth in the Caribbean Sea. The sand it deposits is what has shaped the beach in Salguero, with the help of other elements such as wind, currents or tides. But the story began to change in 2014.
It is difficult to specify a date, but a series of factors coincided to accelerate the erosion. One of them, as Invemar stated in a 2016 report, when it launched the first Salguero coastal erosion alert, has to do with the state of the Gaira River. The low level of its flow stopped providing the same amount of sand. The deterioration of the hydrographic basin, the chopping of trees, the removal of sediments and the interruption of its flow to build buildings, were some of the elements that affected the affluent. During those years, the construction companies also discovered that Salguero could be a good place to expand their business.
“Urban development in the Salguero beach sector plays a fundamental role in terms of changes in the circulation of sediments in the area. Constructions less than 50 meters above the beach area hinders the natural circulation of sedimentary material transported by waves, currents, tides and winds, causing important sedimentary imbalances that increase erosion," was another of the conclusions reached by the Invemar in 2016.
For Professor Camilo Botero, PhD in Management and Conservation of the Sea from the Universidad de Cádiz (Spain) and member of the Sociedad Geográfica de Colombia (Colombian Geographical Society), the big mistake was precisely that. Allowing such tall buildings to be built so close to the sea. “Until 2010 we had well-preserved dunes, but they started building on them and altered everything,” he says.
In 2016, the erosion of the beach began to become so noticeable that it began to worry some apartment owners, who decided to solve the problem on their own. But their solution only ended up ruining Playa Salguero.
That is why nowadays, Salguero beach is divided into two parts. The difference between the two is evident: the first has a beach all year round, while the second only has a few fragments, the size of which varies depending on the season. What explains this phenomenon is a spur that some residents decided to build in 2016 without permission from the corresponding authorities. Since it is not known who built the spur, the authorities have not imposed sanctions.
To put it in a very simple way, that barrier captured the sand that came from the Gaira river, which allowed the formation of that piece of beach. But, "it completely disconnected the contribution of sediments from the river to the rest of Salguero and generated an imbalance on the south side," explains Morales, from Invemar. The result is disturbing: the beach has lost, on average, about four meters each year. And, according to Invemar projections about what could happen in 2024 and 2029, there would be a progressive advance of erosion in 90% of the coastline.
As the change in the dynamics of the coast has been so serious, Invemar points out that, before thinking about dismantling the spur, several studies should be done to know what would happen if it is removed. But they have not been done yet.
Morales, from Invemar, prefers to be prudent when giving an opinion on the solution: "When a decision is made, you must have sufficient technical studies and be very clear about what is being done. We continue to promote solutions based on ecosystems, such as the recovery of the vegetation and the Gaira River basin, and to evaluate the way in which this sector of Salguero is growing. It is necessary to define, in terms of urbanism, what can be allowed and what cannot.”
Botero agrees with that. “Basically,” he says, despite a coastline of 3,000 km, “the problem is that we don't have any coastal regulation in Colombia. There is not even a Coastal Law. This makes it easier to bypass the rules of the Plan de Ordenamiento Territorial (Land Management Plan). We urgently need guidelines for the beach concessions that are made in Colombia.”
In the same vein are the solutions he proposes: better spatial planning and better regulations, restoration of natural sediment transport from the river, and the rehabilitation of mangrove and dune areas lost as a result of construction.
"From the Ministry of Environment, we are committed to coordinate actions between national entities and local institutions to address coastal erosion," says Ximena Rojas. "One of the main bets is to focus on territorial planning, involving water as a fundamental element. If we are talking about marine and coastal zones, we have to involve the sea, and make regulatory adjustments or updates so that coastal land and adjacent seas are included in land use planning.”
Isla Tesoro, a natural barrier threatened by sea level rise and coral reef degradation
In the Parque Nacional Natural Corales del Rosario (Corales del Rosario National Natural Park) there is an island that only park rangers, researchers and the President of Colombia can enter. It has the highest conservation category in the country, as it guards strategic ecosystems, it is a wildlife refuge and serves as a protective barrier for Isla Grande and Cartagena. But erosion, caused by sea level rise and the loss of coral reefs, due to climate change, is still decimating its beaches.
Like a large part of the islands of the Rosario Archipelago, at some point in history, Isla Tesoro was completely submerged. Today the reef terraces are on the surface, at the mercy of the currents, the wind, the waves and the sway of the sea.
Because it is a unique ecosystem within the protected area, Isla Tesoro was declared an "Intangible Zone" in 2007. As Camilo Valcárcel, a park research and monitoring professional, explains, "this is the greatest range of protection that exists within National Natural Parks." Neither tourism nor the transit of boats, nor activities of fishing, extraction or use of resources are allowed.
Just 70 years ago, in the 1950s, this tiny island was a lot less tiny. The first analysis of the change in the coastline of the protected area of the Islas del Rosario archipiélago, carried out by various universities, National Parks and the Parques Nacionales y el Centro de Investigaciones Oceanográficas e Hidrográficas de Colombia (Center for Oceanographic and Hydrographic Research of Colombia), showed that, between 1954 and 2007, Isla Tesoro lost almost 50% of its size, going from 11 hectares to six.
Tropical coral reefs are the most diverse marine ecosystems on Earth. They serve as home and refuge for hundreds of species, and are also a source of livelihood for more than 500 million people worldwide. However, since the 1980s, we have been losing them at an accelerated rate. In the Corales del Rosario and San Bernardo National Park, where 82% of the coral reefs of Colombia's continental shelf are found (and there are colonies that have been growing for more than 350 years), it is estimated that the coverage of living corals is currently less than 30%.
That is why, since 2012, Parques Naturales has promoted the restoration of about 18,000 square meters of coral reefs, and has planted about 14,000 coral fragments in the marine protected area.
In general, the islands of the Rosario Archipelago are a line of defense, a natural barrier against extreme events that can affect cities like Cartagena and its surroundings. Of that barrier, Isla Tesoro is the first in line.
As pointed out in a technical document of 2017 carried out by the Instituto de Investigaciones Marinas y Costeras (Institute of Marine and Coastal Research)(Invemar), Isla Tesoro works as a "wave energy dissipation barrier." In less technical words, this island acts as an obstacle and changes the direction and height of the waves. Its coral platform, which extends more than 300 meters into the sea, gives it these properties.
But, paradoxically, its location at the extreme north of the Park is what also makes Tesoro the most vulnerable island in the Rosario Archipelago, with the most dramatic erosion process among all the islands. For this reason, for years, a team of scientists led by PhD in Marine Biology, Elvira Alvarado, have joined efforts to restore corals, making them more resilient to drastic changes in water temperature, ocean acidification and rising sea levels, to strengthen this natural barrier against erosion.
"Isla Tesoro is a coral transplant area that has been strengthening since 2018," National Parks representatives explain. There is a prioritized area for the "sowing" of new corals, right where the island has been eroded, and where the mangrove cover has been lost due to the impact of the waves.
The restoration in this park has been done through the asexual and sexual reproduction of corals. “Through the fragmentation and assembly of nurseries, we have produced thousands of coral fragments that have been planted as new colonies on the reef. This way we can help recover the living coral cover in a short time,” explains Valcárcel.
The sexual reproduction of corals and the rearing of coral larvae, led by Dr. Alvarado, is a pioneering project in the Caribbean. "With the massive rearing of coral larvae, mainly of species that are in a critical or very vulnerable state of conservation, the aim is to genetically enrich these ecosystems, restore their three-dimensionality and make them more resistant to climate change," explains Alvarado.
With night dives and many hours in the laboratory, 99% fertilization has been achieved in assisted coral reproduction. "That does not happen so easily in nature," says the scientist. It is a win-win. More resistant corals allow, in turn, more resilient coasts against erosion.
These three study cases give a clear overview of the intense erosive processes along the Caribbean littoral of Colombia. It is evident that Colombian beaches are being widely impacted by coastal dynamics, but also by the unsustainable development of different kinds of human structures constructed in the past decades, deforestation of mangroves, coral degradation and transformations of land use. The country needs stable and long-term coastal erosion monitoring, as well as urgent mitigation, adaptation and coastal resilience actions.
"For the year 2023 we are waiting for the National Development Plan to come out, in which we proposed that coastal erosion be maintained as a priority. We have already proposed a project where we are beginning to evaluate nature-based solutions for coastal erosion in the country," concluded the Ministry of Environment.
This story was produced with support from Internews' Earth Journalism Network. It was first published in Spanish in El Espectador on January 15, 2023. It has been translated to English and lightly edited for length and clarity.
Banner image: Tesoro Island, in the Corales del Rosario National Natural Park / Credit: Daniela Quintero Díaz.