Kenya using low technology to restore coral reefs

Unprecedented increase in sea-surface temperature in 1998 destroyed Kenya’s coral reefs. This reduced Kenya’s coral cover by 50-90 per cent with some sites losing all coral cover. Kenya Marine and Fisheries Institute is working on a community based reef restoration project.

Kenya Marine and Fisheries Research Institute is helping protect coral reefs by doing research on reef resilience to fishing, climate change, pollution and sedimentation. It identifies reefs which could be conserved under marine protected areas.

The institute is the government’s research firm that gives information on protecting, managing and conserving ocean ecosystems including coral reefs.

Dr Jelvas Mwaura, head of coral reef research team, said that the institute is helping setting up and strengthening of marine protection areas and community conservation areas. This is to increase reef areas under management.

The last five years have seen increased interest in restoring degraded reefs.  Most of the reefs have lost their reef-forming corals and reef structure has collapsed.

This has led to fall in fisheries habitat and biodiversity as well as livelihoods of those who largely depend on them when healthy.

The institute started a community based, low-technology reef restoration methods in Wasini Island, off the coast of the Indian Ocean. It engaged local community in rehabilitating a one-hectare area through coral gardening concepts.

Coral fragments removed from resilient reefs (reefs which survived previous bleaching impacts) are first farmed or cultured in mid-water nurseries. After they grow to a suitable size they are transplanted to artificial reef structures such as cheaply constructed concrete blocks or coral boulders.

Over 8,000 coral fragments were transplanted and after one year of monitoring, the project was considered successful. This was over 77 per cent survival rate and increased fish abundance within restored site.

“This initiative is in the process of developing a low-tech, community based reef restoration tool kit that will trigger upscaling this restoration efforts,” Dr Mwaura said. “Consequently halt, and reverse the degradation of reefs in other parts of the region.”

What is the state Kenya’s coral reef?

Kenya Marine and Fisheries Institute says that Kenya’s coral reefs are in “fair” condition. Reefs dominated by algae is more than 35 per cent while reefs dominated by hard coral cover is estimated at less than 25 per cent.

Thus, Kenya’s reefs are dominated by algae than hard coral cover. Healthy and functional reefs usually have more hard coral cover and less algae cover.

The institute’s monitoring found reefs under effective management or protection, especially those in marine park and community conservation areas, had higher hard coral cover. They also had focal fish species abundance and less algal cover.

“Conversely, open access (fished reefs) had low hard coral cover (less than eight per cent), lower focal fish abundance and high algal turf cover,” Dr Mwaura said.

Focal fish refers to the few fish species ocean researchers focus on because of their importance in understanding state of more complex marine community.  Examples are groupers, snappers, sweetlips (because of their commercial value) and trigger fish, parrot fish and surgeon fish (because of their ecological importance).

In Kenya, unprecedented increase in sea-surface temperature in 1998 caused devastating destruction to coral reefs by causing bleaching mortality. This decreased coral cover by 50-90 per cent with some individual sites undergoing 100 per cent loss in coral cover.

Dr Mwaura said there have been subsequent bleaching in 2010 and 2016, even though not to the scales of the 1998 bleaching. This caused further decline to coral reef communities in Kenya.

Overfishing, illegal and destructive fishing, sedimentation and pollution are also threatening coral reefs. Corals flourish very well in environment that has clear water, relatively shallow for sunlight penetration to allow photosynthesis and free from sediments, according to Dr Mwaura.

He said that mounting evidences show that the reefs are at a tipping point and could shift from coral-dominated reefs to algal reefs.  If this happens, the valuable ecosystem services provided by coral reefs will be lost.

Dr Mwaura asked authorities to draw suitable policies and management priorities to avoid losing the crucial ecosystem services provided by coral reefs.

Why do we save coral reefs?

Kenya’s 536-kilometre coastline hosts an extensive fringing reefs. It runs from Malindi southward to Vanga-Shimoni bordering Tanzania and patchy reefs with low diversity in the north from Malindi northward to Kiunga bordering Somalia.

The reef-corals are primary engineers or architects of the reefs. They act as a critical habitat serving either as nursery, feeding or breeding grounds for diverse marine and coastal fishes and mammals.

In addition, they provide an array of ecological services including hydrological cycles, carbon stocks, pollution filtration, climate change mitigation and shoreline or coastal protection.

More importantly, they support livelihoods and income sources for nearly two millions of coastal communities.

And they help generate revenue for national economic growth in the country through fisheries and coastal tourism.

Both marine fisheries and coastal tourism are major contributors to the country’s income and employment in Kenya.

 

Interview

Dr Jelvas Mwaura, head of coral reef research team at Kenya Marine and Fisheries Institute, answered our questions.

Water Tower:  What are major factors degrading Kenya’s coral reefs?

Dr Jelvas Mwaura: Our Kenyan coral reefs are facing similar challenges and issues just like in other 100 countries of the world with coral reefs. The huge problem facing reefs at the moment is global climate change, which manifests inform of reoccurring large-scale coral bleaching and mortality events.

In Kenya, unprecedented increase in sea-surface temperature in 1998 caused devastating destruction to coral reefs by causing bleaching mortality that decreased coral cover by 50-90 per cent with some individual sites undergoing 100 per cent loss in coral cover.

There have been subsequent bleaching episodes in 2010 and 2016, even though not to the scales of the 1998 bleaching, that have caused further decline to coral reef communities in Kenya and have also made ecosystem recovery slow over the years.

After the 2016 bleaching event, there are speculations that a second step-decline in reef health, similar to that in 1998, is possible. According to the recent [Intergovernmental Panel on Climate Change, IPCC) report that was released in 2019, climate change is expected to continue causing havoc to coral reefs globally with 90 per cent of the ecosystem expected to be lost in this century if carbon emission continues at the [global warming] 2C above pre-industrial levels.

However, if green gas emission is reduced to about 1.5C above pre-industrial levels, 30 per cent of these reefs could be saved. Now these could act as ‘seed banks’ or refugia that can re-populate other destroyed reefs once climate conditions have been reduced to favourable conditions, something that may not happen in this century.

Aside this global threat, other threats to coral reefs are caused by local anthropogenic stressors that include overfishing, illegal and destructive fishing, sedimentation and pollution. Corals flourish very well in environment that has clear water, relatively shallow for sunlight penetration to allow photosynthesis and free from sediments.

Sediments in the ocean smothers and kill corals. Sedimentation or influx of sediments in the ocean is due to Sabaki and Tana rivers. Conversion of land from natural forest to agriculture and over grazing vegetation has exposed soil to erosion particularly during heavy rainfall or el Nino periods. This results to erosion discharging huge amounts of sediments in the ocean.

Pollution increases nutrients (eutrophication) in the ocean compromising the environment for proper coral reef growth and development. Nutrients can also kill corals. Pollution in the ocean is mainly caused by unregulated discharge of municipal or domestic waste water as well as agricultural effluents. This is a threat for coral reefs that occur in urban areas as well as highly agricultural and populated areas.

Another way to view human impacts on coral reefs in Kenya is to consider how overfishing affect the structure of food webs. The removal of species near the top of a food web by fishing is leading to an increase in abundance of their prey (called a top-down effect). Many reefs in Kenya have been severely overfished, and in many places fisheries have moved lower down the food web, targeting increasing numbers of herbivores such as parrotfish (which are non-commercial fish species).

What are you doing to protect the coral reefs?

One of the key duties of KMFRI [Kenya Marine and Fisheries Institute] scientists is to undertake periodic monitoring of reefs and provide useful information that shows the status and trends of reef health indicators (e.g., corals, algae, fish diversity and abundance); a necessary pre-cursor to inform better management actions and policy statements.

One key area that KMFRI is currently involved to help in protection of coral reefs is through undertaking a detailed research on reef resilience to human-related disturbances such as fishing, climate change, pollution and sedimentation along Kenyan reefs, purposely to identify some reefs that can be prioritized for conservation using MPAs [marine protected areas]. The report identified these highly resilient reefs is produced and made available to stakeholders but challenges are lack of integrated planning processes and funding for their implementation.

A case in point is that, 2010, 2016 bleaching episodes caused 20% death of corals in Kenyan reefs, this is well documented for stakeholders, but reporting has triggered not yet any specific management or policy responses. Aside this, there are a number of initiatives we are involved such as facilitating the development and/or strengthening capacity of MPAs and community conservation areas in order trigger adaptive management at local scales. These efforts are consistent with SDGs [Sustainable Development Goals] targets for 2020 and 2030 that focus on increasing reef areas under management and their effectiveness.

I read that there are initiatives to restore degraded corals in Indian Ocean. What are the techniques used? How do you assess the work done?

With the continuing poor reef conditions occasioned by low or nil recovery trajectories, there is increased demand and interest for active reef restoration in the last five years.

Most of the reefs have lost their reef-forming corals and reef structure has collapsed, leading to decreases in fisheries habitat and biodiversity as well as livelihoods of those who largely depend on them when healthy. Until recently and with funding from World Bank-GEF, KMFRI has pioneered a community based, low-tech reef restoration methods in Wasini Island, located in southern Kenya.

The project extensively engaged local community in rehabilitating a one-hectare area through coral gardening concepts, where coral fragments removed from resilient reefs (survived previous bleaching impacts) are first farmed/cultured in mid-water nurseries until the grow to a suitable size then transplanted to artificial reef structures such as cheaply constructed concrete blocks or coral boulders.

Over 8,000 coral fragments were transplanted and after one year of monitoring, the project was considered successful, with over 77 per cent survivorship and increased fish abundance within restored site. This initiative is in the process of developing a low-tech, community based reef restoration tool kit that will trigger upscaling this restoration efforts, consequently halt, and reverse the degradation of reefs in other parts of the region.

You must have money and skills to protect the coral reefs. Do you have adequate money and skilled personnel?

There are a lot of research currently ongoing with aim of improving the prospect for corals to survive during this climate change era (i.e., improved genes) and innovative ideas are being shared across the countries and at international levels for research trials and scaling for implementation if they succeed.

However, the funding for such project has been a huge bottle neck, especially from the GoK [government of Kenya] that is faced with many other but also demanding areas of concerns. The solution to this lies in seeking sustainable funding mechanisms through partnership with potential NGOs [non-government organisations], private sectors and local communities to support and/or boost reef restoration and adaptation programmes.

How important are coral reefs?

Kenya’s coral reefs are of immense significant importance to not only coastal population in terms of livelihoods and food security but also on national economies and development.

According to recent state of the coast report compile by KMFRI scientists, there are about over 13,000 artisanal fishers who depend directly on exploitation of nearshore reefs through fishing using traditional dugout canoes.

Additionally, the reefs are the major attraction for coastal tourisms because of the beauty and diverse marine life harboured by them such as sharks, dugongs, manta rays, turtle and other reef fish.

This reports indicate that coastal tourism supports about 206,000 jobs directly (which is 3.4 per cent of total employment).

In short, the value of coral reefs in Kenya is estimated at $2.5 billion [Sh270 billion], from small-scale fisheries and tourism sectors, suggesting higher potential for future socio-economic growth that could raise coastal and national economies if reefs were to continue being health.

If nothing or less conservation efforts are undertaken by stakeholders (key government agencies in research and management cycles, tourist-hoteliers, diving resorts, fishing communities), then reefs would decline further and we will lose these huge benefits associated with fisheries and tourism industries as well as coastal protection.

 Any additional comment?

In the absence of clear environmental policy touching on marine ecosystems such as coral reefs, the above mentioned local and global threats can represent a huge challenge to protecting and conserving them in the near future.