Development of Coastal Aquaculture
Phase II		KEN/80/018

Report on a Survey of the Coastal Areas of Kenya for Shrimp Farm Development

TABLE OF CONTENTS

based on work by

Wilfred G. Yap
(Consultant-Shrimp Aquaculturist)

and

Remus J. Landoy
(Consultant-Aquaculture Engineer)

Fisheries Department, FAO, Rome
April 1986

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TABLE OF CONTENTS

EXECUTIVE SUMMARY

1. INTRODUCTION

1.1 Mission Background
1.2 Mission Objectives
1.3 Mission Schedule

2. SURVEY APPROACH AND METHODOLOGY

2.1 Basic Considerations
2.2 First Approximation
2.3 Field Work

3. SURVEY FINDINGS

3.1 Overview of Kenya's Coastal Area
3.2 Lamu District
3.3 Tana River District
3.4 Kilifi District
3.5 Kwale-Mombasa

4. ASSESSMENT OF THE VARIOUS SITES

4.1 Specific Critera Used
4.2 Areas Suitable for Pond Development
4.3 Possible Sites for Penaeid Shrimp Hatchery

5. PROSPECTS FOR SHRIMP CULTURE INDUSTRY DEVELOPMENT IN KENYA

5.1 Potential Areas for Shrimp Farming
5.2 Probable Direction of Development
5.3 A “Fast-Track” Approach to Shrimp Culture Industry Development in Kenya
5.4 Extending Shrimp Farming Opportunities to the Grassroots through the Estate Concept

6. POSTSCRIPT

7. REFERENCES

LIST OF TABLES

Table 1. Length of Kenya's coastline, broken down by district

Table 2. Inventory of tidal swamps and tidal flats in Kenya

Table 3. Summary of field observations, Lamu District; Kenya

Table 4. Result of field survey and soil analysis, Tana River area, Kenya

Table 5. List of saltworks operating or scheduled to operate within the Ngomeni to Kurawa area and their corresponding hectarage

Table 6. Result of field survey and soil analysis; Ngomeni to Kurawa area, Kenya

Table 7. Result of field survey and soil analysis; Port Reitz and Port Tudor, Mombasa, Kenya

Table 8. Summary of field observations; Kwale District, Kenya

Table 9. Summary of Findings; Survey of the coastal areas of Kenya for shrimp farm development

Table 10. Inventory of first reservoirs of various saltworks which could be stocked with P. monodon on an extensive basis

Table 11. Inventory of potential shrimp culture areas in Kenya

LIST OF FIGURES

Figure 1. The coastal area of Kenya showing boundaries of administrative districts.

Figure 2. Location of sampling stations at the northen portion of the Kenya coastline from Kilifi Creek to Lamu. Site survey mission, Project KEN/80/018.

Figure 3. Location of sampling stations within the southern portion of the Kenya coastline from Mombasa to Vanga; Site survey mission, Project KEN/80/018.

Figure 4. Schematic representation of a typical tidal swamp and flat in the coastal area of Kenya.

Figure 5. Horizontal salinity distribution, surface and one-meter layer; Tana River, Kenya; 21 March 1986, from 13.00 to 13.50 hours.Low: 1.33 m at 08.02 h; High: 2.09 m at 14.08 h).

Figure 6. Vertical salinity profiles at three different sections of Tana River, Kenya; 21 March 1986, from 13.00 to 13.50 hours. Low: 1.33 m at 08.02 h; high: 2.09 m at 14.08 h).

Figure 7. Site of abandoned Tana Saltworks at Mto Kilifi area, Tana River District, being proposed for an integrated saltworks and shrimp farm project.

Figure 8. Map of Kurawa to Ngomeni area, Kilifi District, Kenya, showing location of saltworks (3 sheets).

Figure 9. Diagrammatic presentation of the optimal elevation ranges for various shrimp culture systems based upon tidal characteristics of Kenyan waters.

Figure 10. Typical soil profiles at various sites along the coastal area of Kenya.

Figure 11. Tidal swamps within Mombasa showing sites with potential for shrimp farm development.

Figure 12. Tidal swamp area along the Tana River Bank showing sites deemed suitable for semi-intensive or intensive culture of Penaeus monodon.

Figure 13. The abandoned Bellazoni estate along the Tana river showing portion which could be developed for shrimp farming.

Figure 14. Sites found ideal for shrimp hatchery development and extent of coastline from Kilifi to Malindi where other potential sites may be found.

APPENDIXES:

I Survey Mission Schedule

II List of Persons Met

III Problems of Construction and Management on Cat Clay Soils

1. INTRODUCTION

2. FORMATION OF ACID SULPHATE SOILS

3. FIELD IDENTIFICATION

4. PROBLEMS OF POND CONSTRUCTION AND PLANNING

5. REMEDIES FOR PONDS BUILT ON ACID SULPHATE SOILS

6. MANAGEMENT MEASURES

7. SUMMARY AND CONCLUSIONS

8. REFERENCES

IV The Salt Industry in Kenya and its Potential Role in Coastal Aquaculture Development

V Cost Comparison on Manual versus Mechanical Pond Construction

VI Single Family versus Estate Concepts of Aquaculture Development

VII Beyond Shrimp Farming

VIII Suggested Plan of Action for the Various Agencies Involved in Coastal Aquaculture Development in Kenya

IX Terms of Reference in Detail

EXECUTIVE SUMMARY

Survey of Kenya's Coastal Area for Shrimp Farm Development Rationale:

The survey mission was organized to identify suitable sites for shrimp farm development along Kenya's coastal area.

Approach:

The survey focused on the two most basic parameters in coastal aquaculture, namely: soil type, and capability to be watered by tide or with the least energy cost.

Selection Criteria:

Findings and Assessment:

Total tidal swamp and tidal area of Kenya, 50 400 ha (Lamu, 28 400; Tana River, 3 000; Kilifi, 6 400; Mombasa, 3 100; and Kwale 9 500 ha).

Lamu and Kwale areas: substrate sand and peaty-sand, not suitable for pond construction.

Kilifi district: area from Ngomeni to Kurawa with sandy-clay-loam to silty-clay loam substrate suitable for pond construction but elevation range of 2.5 to 3.8 m limits use to pump-assisted systems. Furthermore most areas already occupied by saltworks, covering 7 922 ha including portions high ground, tidal swamps and flats. However, existing saltwater reservoirs appear suitable for extensive shrimp farming.

Mombasa: certain portions of Port Tudor and Port Reitz with loam or silt-clay loam substrates are suitable for pond construction. Some mangrove areas with elevation range of 1.8 to 2.3 m suitable for extensive systems and others with elevation range of 2.4 to 4.0 m: all tidal flats too sandy for pond development. No pollution problem at present but future developments generating effluents possible.

Tana River District: North bank of Tana River found to have clay to sandy-clay substrate suitable for pond construction but elevation range of 3.0 to 4.0 m limits use to pump-assisted systems. Abandoned agricultural estate (Bellazoni) along East bank of old Tana River course opening at Mto Tana per Kenya soil survey reports must have portions suitable for pond development. Access within Tana River Basin problematic during wet months of May-June and November-December.

Prospects:

Total of 3 950 ha found suitable for shrimp farm development. Figure includes 800 ha reservoir within and 1 000 ha mangrove adjacent or between saltworks with access problem except to saltworks operators.

Only 500 ha (Port Tudor, Port Reitz 150 ha) plus 800 ha reservoir area deemed suitable for extensive system.

All others (Tana River North bank, 1 000 ha; Bellazoni, 500 ha; mangrove area within saltwork periphery, 1 000) suitable only for intensive system.

Suggested Development Approach:

Immediate and “fast track”: promote extensive shrimp farming within saltworks reservoir using P. monodon and P. indicus. Modern shrimp hatchery and extension service only major requirements.

Medium to long term: adapt semi-intensive and intensive technology to Kenya conditions and explore the use of Artemia biomass produced in saltwork evaporation ponds as supplementary feed. Explore full integration of shrimp culture and Artemia culture with saltworks.

Long-term prospects for Kenya's coastal poor; explore the possibility of a parastatal body, or a cooperative providing the infrastructure through the concept of afishpond estate as away of giving opportunity for low-income families on the coast to become shrimpfarm owners or operators thus benefitting in the wealth that Kenya's coastal land and water can offer.

Postscript:

Alternative avenues for coastal aquaculture development outside shrimp culture should be explored to produce food fish and to generate livelihood opportunities.