How rising sea level threatens islands' existence in Tanzania

Dar es Salaam. The rising sea level (RSL) is threatening the existence of islands and islets in Tanzania due to the massive beach erosion and the rapid loss of vegetative cover, calling for immediate adaptation measures.

The persisting RSL is a dire consequence of climate change, primarily driven by the progressive melting of glaciers in the Arctic.

Over the last two decades, both satellite and coastal sea level data indicate a considerable increase in the rate of sea level rise per decade, with projections suggesting a worsening trend in the 21st century compared to previous centuries.

The United Nations Framework Convention on Climate Change (UNFCCC) says the global average temperature reached 1.1 degrees Celsius in 2023, marking a significant increase from the below 0.5 degrees Celsius recorded half a century ago.

The consequences of RSL are evident along the coastline of the Indian Ocean, negatively impacting the Tanzania islands of Mafia, Unguja, and Pemba, leading to a reduction in size and endangering the lives of inhabitants.

The erosive force of RSL has been severe, therefore making effective management a challenge and posing a major threat of erosion-induced disappearance for these islands and islets, unless immediate adaptation measures are implemented.

On Mafia Island, the adverse impacts of RSL are starkly visible in Kilindoni and along the coastline of Banja Village, located over 45 kilometers from the heart of the island.

Protective infrastructure, such as walls constructed at the Kilindoni Area to mitigate devastation from ocean water, has been breached, leading to the invasion of ocean waters into areas once shielded. This has resulted in major beach erosion, uprooting, and washing away of coconut trees and other vegetation along the coastline.

Ms Hawa Salumu, a 62-year-old resident of Mafia Island, carrying her business for the last 30 years in the Kilindoni Area, said the situation was alarming, hinting that the impacts of climate change have led to the shrinking size of the Bwejuu islet as an example.

“The threat is compounded by the potential displacement of residents, as seen during past tsunamis, prompting discussions about relocation,” she told this reporter.

Mr Ally Suleiman, 66, emphasised the need for urgent intervention, warning of the imminent loss of coastal vegetation and infrastructure if action is not taken promptly.

Mr Said Mohamed, a fisherman who also carries his activities in the Kilindoni Area, reminisces about the protective role of coastal vegetation in mitigating the impacts of RSL, underscoring the importance of reforestation to safeguarding the island's future.

Similar challenges were observed in Banja Village, where longstanding trees are succumbing to the relentless encroachment of ocean waters, leaving behind a barren landscape.

Banja village chairman, Mr Majid Boi, stressed the urgency of research and immediate action: “There is a need for collaborative efforts between citizens and relevant stakeholders to implement mitigation strategies, particularly tree planting.”

The adverse effects of RSL extend beyond coastal erosion, affecting freshwater sources like River Number Three in Kibada Village on the island.

A member of the village executive committee, Mr Khatibu Hassan highlighted how RSL has disrupted traditional fishing practices and compromised access to freshwater resources, exacerbating food insecurity among villagers.

“There is a need for government-led climate adaptation projects alongside community-driven conservation efforts to address the multifaceted challenges posed by RSL,” echoed a villager, Mr Makame Ndimbwe.

In Kirongwe Ward, Kaskazini Division, on the Island, the withering of mangrove trees further underscores the impact of climate change on local ecosystems.

Mr Abdul Faki, the former ward councillor and Mafia district council environment officer, emphasised the need for adaptive measures to mitigate the loss of vital coastal habitats.

“Initially, we thought the withering was caused by wastewater from the Alphakrust Ltd fish processing factory. However, laboratory tests confirmed that industrial residues had nothing to do with what was happening; rather, it was an adverse impact of climate change,” he said.

Urgent actions are imperative to address the escalating threats of RSL to Tanzanian islands, with Mr Faki suggesting that a comprehensive approach involving both immediate adaptation measures and long-term strategies for climate resilience and sustainable development is required.

Similar incidents were witnessed in different areas of Unguja and Pemba, suggesting that the Tanzanian islands, like many other places in the world, were increasingly feeling the pinch of climate change.

Government reaction

The then Mafia District Commissioner (DC), Mr Zephania Sumaye, said beach erosion was evidence that RSL was real on Mafia Island.

“Beach erosion has led to the uprooting of coconut and mangrove trees despite government efforts to reduce the impacts through planting mangrove trees whose effectiveness in withstanding the strength of ocean waves cannot be overemphasised,” he said.

He welcomed stakeholders’ collaboration in the implementation of climate change mitigation projects.

The Environment Department at the Vice President's Office in the Union Government couldn’t provide insights over mitigation projects in the pipeline and future plans to protect islands in Tanzania mainland from the impacts of climate change.

However, the assistant director at the Environment Department of the First Vice President of Zanzibar, Mr Mwalim Khamis Mwalim, said the island’s size wasn’t the same as it used to be in the past.

“The size will continue declining if no proper climate change adaptation measures are taken. They should also be conserved as per the government’s directives on proper use of resources and curb incidents of environmental degradation,” he said.

The director of environment at the First Vice President’s Office in Zanzibar, Ms Farhat Ali Mbarouk, said her office conducted a study in 2019 aimed at establishing the impacts of beach erosion, salt water intrusion, and sea inundation on the Unguja and Pemba islands.

The study, funded by the United Nations Development Programme (UNDP), was required to come up with climate change adaptation measures, according to her.

She hinted that Nungwi, Makoba, Mto wa Pwani, Kombeni, Pete, Michamvi, Pingwe, Michamvi Kae, Jambiani, Kikadini, and Jambiani Kibigija were surveyed in Unguja.

While in Pemba, the studied areas are Msuka Mashariki, Majenzi, Gando, Wingwi, Kangani, Mjimbini, Wambaa, and Kisiwa Panza.

The study findings document seen by The Citizen show that Nungwi, Mkokotoni, Bumbwini, Michanvi Kae, Michanvi Pingwe, Michanvi, Kisakasaka, Pete-Jozani, and Jambiani were places earmarked to have been severely affected.

In Pemba, the seriously affected areas are Msuka, Gando, Micheweni, Wingwi, Tovuni, Kwa Kingoji, Kwa Vunde, Kwa Tumbo, Wambaa, Kangani, Kwa Sharifu, Wakuungwe, Maotwe, and Kisiwa Panza.

She admitted that beach erosion was a serious challenge in Zanzibar, with investors in the hotel industry feeling the pinch of water hitting their premises.

“They have been consulting the government over recommended mitigation measures. However, the government has allocated funds in the 2023–24 fiscal year for conducting feasibility and design studies for required intervention measures in mostly affected areas,” she said over the phone.

“Much has been done in other places, such as the Forodhani Area, where a wall has been constructed under World Bank (WB) funding. Similar climate change adaptation projects have been executed in Kisiwa Panza, Pemba, and Kilimani to prevent seawater intrusion from affecting agricultural land,” she added.

She said that apart from adaptation measures, citizens are provided with alternative livelihood mechanisms to reduce the contribution of human activities, deforestation, and general environmental degradation.

However, Mr Mwalim said his department has embarked on a survey to establish places severely affected, the types of effects such as human settlement, income generation activities, and food production, and finally suggest appropriate intervention measures.

“Gathered information will be used for establishing a database that will ease access to climate change-related information. The collected information will also enable the government to prepare climate change mitigation project write-ups for implementation by various stakeholders.

Climate change adaptation projects

According to Mr Mwalimu, the government constructed two walls in Panza Island in 2018, funded by the Least Developed Countries Fund (LDCF).

He said the project replaced collapsed traditional walls that threatened human settlement and government structures in the area, including schools that were on the verge of splitting and major destruction.

“The project involved planting over 200 acres of mangrove trees. The government also executed a 500-metre wall project in Nsuka Fish Port in 2022,” he said.

He said that in the Sipwese area, climate change disrupted communication between two villages and restricted the free movement of people from one place to another.

“Schoolchildren were forced to have two pairs of clothes to be worn when crossing the area and one to dress in during the classroom,” he said, noting that a similar situation faced residents who were seeking social services.

“However, the Revolutionary Government of Zanzibar (RGZ) and the United Republic of Tanzania (URT) have co-funded the implementation of an ongoing 200-metre-long ridge project that will serve as a bridge and free citizens from the present nightmare,” he said.

Experts’ word

A climate change expert from the University of Dar es Salaam (UDSM), Prof Pius Yanda, said global warming will continue leading to witnessed RSL, provided the world community continues emitting greenhouse gases in the atmosphere.

“RSL is associated with two major factors: snow melting in the north and thermal expansion due to an increase in water temperature. With the increase in RSL, we should expect more coastal erosion and saltwater intrusion, therefore affecting agriculture activities,” he said.

“This is because salt water will turn agricultural land saline, forcing citizens to abandon the land or engage in growing salt-resistant varieties,” he said.

He said most coastal communities that used to get water from bore wells face a similar threat as the fluid increasingly turns to saline due to the increasing rate of saltwater intrusion, therefore compromising the livelihood of coastal communities.

“If we don’t compel and contextualise emissions of greenhouse gases, these challenges are bound to increase over time,” he said.

Regarding adaptation measures, Prof Yanda said Tanzania was in favour of what is termed the biological approach, saying if properly managed, mangrove forests will act as buffers to strongly protect the coastal areas.

Supported by Bill & Melinda Gates Foundation