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Managing the pathogens threatening St Helena’s biodiversity and food security

About the project

St Helena’s endemic trees, insects and crops are threatened by unidentified introduced pathogens, and/or changes to endemic pathogens through climate change. This project is surveying and identifying pathogens associated with tree death (including the Peaks nursery stock), declining crop yields and insect populations. Methods developed through CABI’s Plant wise initiative will be used to build capacity in diagnostics and management across all sectors, supporting growers, conservationists and foresters. Identification of pathogens threatening insects and keystone cloud-forest species is the first step to understanding and reversing the decline of the endemic ecosystem and reducing the threat of extinction of St Helena’s unique flora and fauna.

Project Importance

Surveys of the pathogens impacting agriculture will allow for a better understanding of the threats to food security and facilitate the development of agriculture practices that preserve biodiversity and are more resilient to climate change, thus reducing the necessity to import food. Another important aspect of the project is to build island capacity in disease identification and management through training and improvements to laboratory facilities. The development of management strategies and training will be provided after initial surveys reveal the extent of the problems and which pathogens are causing disease.

Project Deliverables

Develop an action plan to mitigate threats of newly discovered pathogens including best practice guides for extension workers and conservationists



Capacity building/training of stakeholders across conservation, agriculture, biosecurity and forestry sectors


Rollout of best practice methods on farms, forest nurseries and cloud forest restoration. Early impact assessment in the final year of the project


our work extends to key biodiversity areas, such as the peaks also forestry and agricultural land. We identify odd symptoms of health and how common they are amongst the locations population, by which we would examine; severity and origin of the disease. For example; mist to leaf or soil to root etc.


when collecting any diseased material, it is important to securely put it into a bag and label it for later use within the lab. Because of the decay of EDNA within the collected material, which could affect results in the lab. it must be stored within a refrigerator if not purposed immediately to increase the chance of cultivation.


The last step in this process is carried out in the lab. Where samples collected from the field are sterilized and put into agar plates with limited nutrients to restrict growth of piggyback organisms such as bacteria. when growth is evident, sub culturing can commence onto nutrient rich agar plates, where the disease is grown and identified

Step 1 Separate samples from collected materials
Culture samples
Step 2 once growth is evident, it is required to sub culture the hyphae (semi-transparent tubular structures) furthest from the sample, to be sure that we are only sub culturing culturing the fungus and not bacteria into our nutrient rich plate of agar
Identifying growth & sub culturing
Step 3 A week later after sub culturing the fungus, it will start to grow rapidly, until the fungus starts to sporulate (Produce spores). It would then be put under UV and white light that are timmed to switvh on at 12 hour intervals to promote further growth.
Cultivating fungi
Step 4 once the spores are present they will be removed and identified by a mycologist, furthering our understanding of it and providing new measures of mitigating it.
Collecting spores

Our PhD student Amy working on the endemic trees

For more information on the science being done on the island and the problems that must be overcome, visit Amy’s website where you will also get to know a bit about her and her perception of this unique remote island.

“St Helena’s cloud forest is home to a diverse range of fauna and flora, with many endemic trees making up the iconic landscape. However, with climatic gradients becoming smaller under climate change and the movement of non-native material between isolated places, the risk of invasion from unwanted pests and diseases is more and more problematic.

The black cabbage tree is just one species on St Helena that appears to be affected by disease-like symptoms, however the cause of these problems is not yet known. By exploring the peaks and it’s microbiome, an indication of any disease-causing agents may be uncovered, untapped beneficial microbes discovered and abiotic complications better understood. 

This project will provide new insight into an amazing ecosystem yet unexplored to it’s full potential. This may impose some challenges due to the huge amount of new data, however the findings and possibilities for collaborations will make this an incredible research opportunity and aid the preservation of this endemic forest.” 

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Canarvon Court, Education Learning Centre, Jamestown, St Helena


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T. 00 (290) 22607

St Helena Government