Phase II – The Problem of Shoreline Changes, its Socio-economic Impacts and Mitigation Options in Eastern Africa

Shoreline change particularly coastal erosion is one of the major environmental challenges in most countries in the WIO region. Extensive and significant shoreline change, whether due to anthropogenic or natural causes, is known to be a major contributor to environmental degradation, with consequent adverse effects on communities and their livelihoods and tourism development in the WIO region. The main goal of the study was to investigate the underlying causes of shoreline changes, their socio-economic impacts and recommend effective and relevant mitigation and adaptation options. Specific objectives of the study for each coastal section include: (1) Establish the rate and pattern of shoreline changes and the most important natural and anthropogenic causes of shoreline changes by systematic monitoring over 2 years with reference to existing hydrodynamic, meteorological and geological datasets in combination with other historical datasets (such as aerial photos/ satellite images, meteorological, oceanographic etc.). (2) Establish the sources, transport paths and relative importance of beach and platform sediments, including those derived from rivers and streams, from coastal erosion and those produced by calcium carbonate-fixing marine animal and plant biota. (3) Determine the relationship between shoreline changes and coastal communities’ livelihood patterns including tourism; these include the impacts of human activities on shoreline change and vice versa. (4) Based on the findings of the three objectives above, forecast the impacts of climate change and its anticipated sea-level rise on these coastal sections. (5) Examine the existing mitigation measures in relation to their effectiveness (functional and cost) and efficiency and recommend appropriate options. (6) Examine the existing institutional framework (policies and legal mechanisms) in relation to their effectiveness in shore management and recommend appropriate options.

The study was implemented in two coastal sections of the two Eastern African countries (Tanzania and Kenya), namely, the Kunduchi coastal section, in Tanzania and Shanzu Bamburi coastal section in Kenya. These areas are experiencing shoreline erosion/accretion, high investments in tourism, pressure from proximity to major urban centres (Mombasa & Dar es Salaam), dependence on fisheries by a large section of the coastal community. Further both areas have beautiful coral reefs and sea-grass beds.

Historical data sets on wind and sea level changes were extracted from relevant agents (meteorological institutions, University of Hawaii Sea level Centre). Oceanographic datasets (waves conditions, currents speed and pattern) were obtained in situ using relevant instruments such as wave gauges, current meters, and buoys (or drogue). Beach profile was measured using standard levelling method and GPS was used to keep track of the different study sites.  Sediment characteristics of beaches were determined using grain size analysis.  Shoreline changes as well as land use changes were documented using remote-sensing methods i.e. Satellite images and aerial photos. Other methodologies included field surveys, consultative meetings with relevant stakeholders, questionnaire surveys.

The targeted beneficiaries of this study included local community, the scientific community, coastal managers, coastal hotel developers, Education Institutions, Media, planners, decision and policy makers and other relevant stakeholders.

The principal output of this project is a manual “Shoreline Change in Tanzania and Kenya: Manual for Assessment and Design of Mitigation” that provides guidance on methodologies for the assessment and mitigation of the risks from shoreline change. The manual is based on the findings of this research study, plus other published and unpublished information comprising research by individuals as well as guidance documents from national and international organisations including the Intergovernmental Oceanographic Commission (IOC) of UNESCO. The production of this manual was initiated and supported by WIOMSA through its Marine Science for Management (MASMA) programme in recognition of the lack of such guidance in the WIO. Specifically, the manual: (i) reviews the existing legal and institutional frameworks of Tanzania and Kenya as they relate to ICAM and specifically the management of shoreline change. It also includes proposals for making these frameworks more effective, (ii) points out the importance of knowledge of the geology and geomorphology of a coastal area in understanding and assessment of shoreline change, (iii) provides appropriate methods for monitoring shoreline change and analysing its causes, (iv) provides key factors that determines a community’s vulnerability and the risk of damage or loss, and (v) provides guidelines on choosing mitigation approaches.

The manual is expected to be a useful tool both for managers and scientists in various government institutions in the WIO region dealing with the issues of integrated coastal zone management and those involved in the management of the impacts of climate change through adaptation and mitigation.

The manual can be cited as Yohanna Shaghude, Wainaina Mburu, Russell Arthurton, Alfonse Dubi, Simon Gachuiri, Juma Kangwe, Charles Magori, Flower   Msuya, Rose Mwaipopo, Ntahondi Nyandwi, Jacob Ochiewo, Harrison Ong’anda, Rose Sallema Mtui, Ignatia Sanga, Mwanahija Shalli and Jacqueline Uku. Shoreline Change in Tanzania and Kenya: Manual for Assessment and Design of Mitigation Strategies. WIOMSA Book Series No. 16. Zanzibar: WIOMSA. xii+ 85pp.2015.