• In the 1960s, fishermen from Ayetoro in southern Nigeria used to express their frustration about how far the sea was from their homes
• Today, the situation has changed drastically, with the sea advancing across the land by up to 65 meters yearly. Only six of the original 21 streets remain
As Mayokun Iyaomolere wove his way between large puddles lining the walkway known as Broad Street in the southern Nigerian community of Ayetoro one day in late June, he couldn't help but feel a sense of astonishment.
He found it incredible how quickly the sea had moved into the area. As he progressed on his mission to gather data, he was eventually forced to use pieces of wood — the last remains of wooden-stilt homes felled by April storms — as stepping stones to traverse the waterlogged broadwalk.
Ayetoro is a low-lying coastal community in Ondo State, southern Nigeria. It is bordered to the north by the sprawling shore of the Atlantic Ocean and to the south by serene lagoons.
"I grew up about an hour from here, and even then, I heard stories of the ocean frequently wreaking havoc," Iyaomolere said, offering his local knowledge as background to what is becoming a major problem for this area: like a magical tale from a Gabriel Marquez novel, it is being devoured by the sea.
"I always wondered how this community experienced such a dramatic shift in its fortunes. In its early days, Ayetoro was renowned for its flourishing fishing industry, which brought prosperity to the region."
Driven by curiosity and a desire to learn more about this phenomenon, Iyaomolere pursued a two-year master's programme in Environmental Control and Management at the Obafemi Awolowo University in Nigeria. When the time came to choose a research topic for his thesis, there was no question about what he wanted to explore.
"I knew I would investigate the flood vulnerability of coastal communities in the Ilaje region, of which Ayetoro was among them," the 29-year-old researcher said.
In 2017, Iyaomolere made his first trip to collect data for his research. At that time, Ayetoro was a kilometre from the shoreline. Anecdotal evidence from community leaders suggested that the community used to be farther from the ocean.
"In the 60s, the sea was very far from where the people lived. Ironically, it was the major problem fishermen were facing," said Oba Ojagbohunmi, the community's traditional ruler. "But at the moment, boats can no longer berth here."
In the 60s, the sea was very far from where the people lived. Ironically, it was the major problem fishermen were facing. But at the moment, boats can no longer berth hereOba Ojagbohunmi
Before the discovery of oil in Ayetoro's waters, the local economy thrived on fishing, an activity that employed more than half of the population.
"In the past, a fisherman could earn up to 500,000 Nigerian naira ($656) in one day during the peak of the fishing season," said Pa Lawrence Lemamu, the chairman of the fishermen's association in the community. "With this income, fishermen were able to live well, build houses and train their children in good schools," he said.
However, the devastating impact of oil spills on the rich marine habitat and the advancing ocean that has inundated the fishermen's riverside homes forced many of those who earned a living from the sea to migrate to other communities, where the shores could still support fishing activities.
An economic analysis of artisanal fisheries in Ayetoro and three other Ilaje fishing communities projects a profit of 158.9 naira (US$0.21) for every naira invested in fishing activities. But the study's authors have called for the coastal waters to be properly managed to ensure the "sustainability of fisheries resources".
"This has always been a pain point for me and inspired me to learn more about coastal flooding," Iyaomolere said.
As the principal investigator, Iyaomolere made several more trips to the community.
"I had to go and observe again and again. At some point, I had to travel down to Lagos to visit the Nigerian Institute for Oceanography and Marine Research, but the institute's library did not have recent data to support my research. It took a year to get all the data I needed," Iyaomolere said.
He completed his data-gathering by the second half of 2018 and began his analysis. One significant discovery was that the community was losing its land to the sea at a rate of 65 metres per year. Values above 15 metres generally indicate "very high vulnerability" to coastal flooding.
Supported by the evidence from his research, Iyaomolere sought ways to engage influential stakeholders to raise awareness.
He attempted to bring the state government on board, but his efforts to get across to the commissioner of environment proved futile. He re-strategised and turned his attention to more receptive community leaders.
During this period, he met Emmanuel Aralu, then the secretary of the Ayetoro Youth Congress, who helped him establish connections with key decision-makers in the community.
He also discovered that in 1995, two Nigerian researchers had published a study which suggested that Ayetoro and Awoye (an adjacent community) were at risk of being lost "even with a 0.2-meter rise in sea level".
Due to global warming, the global mean sea level has already risen 22-24cm since 1880 (over 0.2 meters), and it could reach two metres by 2100 if greenhouse gas emissions are not controlled, according to a 2023 assessment report by the Intergovernmental Panel on Climate Change (IPCC).
Coastal areas with low elevation, typically ranging from one meter to 20 meters above sea level, are particularly vulnerable to the impacts of rising sea levels.
During his data collection for the research, Iyaomolere had estimated Ayetoro's elevation to be 2m above sea level.
But when he repeated the analysis this year, he found the community's elevation level to be zero.
"This means the community is at the same level as the sea, which is why the ocean attacks have increased," he said.
"At the moment, we have lost two-thirds of the community," said Aralu, unveiling a pencil-drawn map of the community on yellow cardboard. The map portrays a clear division of the community into two similar sections, east and west, with the prominent Broad Street positioned at the centre.
Aralu explained that the eastern region has suffered the most damage from the sea's incursions. It once boasted 21 streets, including fishermen's riverside homes, but only six remain today.
While part of the area is protected by a makeshift levee, the advancing ocean now laps the edges of Broad Street. Surging seawater crashes over the walkway's raised borders during high tides, flooding the western section and streets at both ends of the walkway are rapidly disappearing.
Based on interviews with locals, Iyaomolere found that seawater intrusion in Ayetoro and neighbouring communities coincided with the beginning of offshore oil exploration in surrounding waters.
"Oil exploration tampers with the nature of the soil beneath and leads to land subsidence, and when the land in an area is sinking, it is more exposed to sea level rise," he said.
Although no official measurements have been carried out, various Nigerian researchers have cited land subsidence rates ranging from 25 to 125 mm per year in oil-producing coastal communities. Iyaomolere attempted to conduct measurements to support the qualitative evidence he gathered but could not access the necessary tools.
"Many feasibility studies have been done," stated Ojagbohunmi, the community's traditional ruler. "But what is left is the political will to synergise efforts of various bodies."
In Ayetoro, there have been two unsuccessful shoreline protection projects. The Nigerian government awarded the first contract to Gallet Nigeria Limited in 2004, but the contractor could not carry out the work, resulting in the termination of the contract.
In 2009, a new contract was awarded to Dredging Atlantic Limited to build an embankment along the shore and reclaim the land lost to the encroaching Atlantic Ocean.
"They came with engineers, workers and sophisticated equipment," said Ojagbohunmi. According to him, it looked promising until they encountered difficulties sourcing sand to support the construction. "Eventually, they left, too." Since then, no new projects have been implemented to resolve the issue.
"It shows their lack of preparation," said Iyaomolere. In his research, he found that strategies deployed by the government to manage coastal flooding do not always match the coping strategies employed by local residents.
Iyaomolere has developed solutions to Ayetoro's disappearing streets that could see the land recovered by harnessing local knowledge and a strategy called Integrated Coastal Zone Management (ICZM).
ICZM is a strategy to plan and manage coastal regions. It emphasises the need for public and private agencies to utilise scientific and transdisciplinary knowledge and to collaborate with researchers to manage coastal flood risks and support adaptation efforts.
Scientific knowledge has been recognised as an important pillar to motivate adaptation, especially in the global south, where scientific evidence has been inadequate for a long time. Iyaomolere is one of a handful of environmental scientists whose research is helping to generate evidence around areas like Ayetoro becoming increasingly prone to coastal flooding.
His thesis has been included in Springer's handbook on Disaster Risk Reduction for Resilience, which provides information and strategies to reduce disasters and associated losses as proposed in the Sendai Framework — a United Nations-adopted framework for disaster risk reduction.
However, when asked if the government has ever contacted him to contribute his coastal management expertise, Iyaomolere's response was an emphatic "No."