Overview of Land-based Sources and Activities Affecting the Marine, Coastal and Associated Freshwater Environment in the West and Central African Region UNEP Regional Seas Reports and Studies No. 171 Note: The preparation of this Report was cnmmissioned by UNEP, Unrted Nations Environment Progrdmme from Prof. E.S Dlcp. (currently Sen'lor Programme Officer, Division of Envlronmenlal Infonnation, Assessment & Early Warning) under Project FPil100"96-01. Design and layout by Mwangi rnoun. UNEP, The designations employed and the presentation of the materi"ls in this document do not imply the expressions of any opinion whatsoever on the part of UNEf' concerning the tegal status of any Stata, Territory, city Or area, or ils authorities, or concerning the delimit"tion of their tronters or boundarios, The document contains llle views expressed by the author(s) aclillY in lheir individual capacity and may not necessarily renecr the vi~w~ of UNEP. (\;;1999 United Nations Environment Prowamme The Global Programme of Action for the Protection of the Marine Cnvironmenl from Land-based Aclivitie\; GPA Co-crdlnatlon Office P.O. Box 16227 25110 BE The Hague VJsiting address: Anna Paulownastraat f , The Hague, The Netherlands West and Central Africa Action Plan Rcgionul Co-ordinating Unit c/o Ministere de l'Environnement et de la Foret 20 BP 650, Abidjan 20 Cote d'lvoire This publication may 00 reproduced in whoie or in pari and in any (om, for erllJcatirmal and non­ profit purprn;l!s without sWH"oial permission from the copyright holder, provided that acknowledgement of the source is made. UNEP would appreciate receiving a copy of any pucncatoo that uses this material as a source. No use of this publication may be made for the resole or for any other commercial purposes whatsoever wilhout the prior permission in writing of UNEf'. For bibliography purposes !his document may be cited as: UNEP: Regional Overview of Land-ba~ed sources and Activities Affecting the Coa~1al and Associated Freshwater Environment in the West and Central African Region. UNEP/ GPA Co·ordination Office & west and Central Africa Action Plan, Regional Co_ordinating Unit (1999). 110 pp. ISBN: 92-807-1800-3 Front cover picture: Some aspects of aquatic invasive weeds in African cousla/lagoons (top left), Aerial view of fhe Pori orDakar, Sellegal (middle), Sand consolidation impacts resulting from Senegalese Chemical IndustriOs discharges, South CoastotDakar(battomJ, Pholo by S. DIOP. iii Table ofContents List of Figures .. ListofTables. ,,, .....,,IV ........v , Preface Execu~ve Summary __ ......" ...... ......Vi Background .. .vil I Infroduction. , A Natural conditions and processes" ..." " " ,1 I 1. Regional morphology and river basin drainage.. , 2. General oooanography, GoastJl morphology and processes. , 3. Ecosystem and species diversity. , e. Anthropogenic Impacts: demography and urbanization, industrial, agricultural activities and development ..." ,........,..." "......... c Socia-economic implications oi anthropogenic alteratioilS including losses of cultural heritage sites. .""....... ,....,,,..... ,,..... ,6 Regional overview on land-based sources of pollution: idenfification " and assessment oIproblems.. .........,......,.. ."" . •• n •••9 III. Emerging and foreseeabtp. rroblems " . tz 'V. Strateqies and meaSures " . ."..... 12 V. Priorily for action including regionaVinternational cooperation activities " .. • n ••13 V,. Main conclusions and reccmmenoeuoos.. ". .16 VII, Country-by-counlry analysis of land-tmsed sources and activities .. .".17 A ArlY[JI~........ " ........... ........,18 B. Benin ........ ,21 C Chad , .." ,24 o Congo (lJemocratic Republic) .nn 26 C. C¢te d'ivoire .nn 29 e. Gambia. .n .. nn. nn.34 c. Ghana. ..40 Guinea . .nn. nnn. nn. n.44 ", Guinea-Bissau. nn •••51 , Liberia . sa , Mauritania .,.,., ,. ....."....... ......54 t. Nigeria , " , , .. ..55 M. Sao Tome and Pnncir>e •• n •• n .67 M Senegal.. .. n70 O. Togo. ..78 VIII. References •• n ••• eo Annex I. List of Addition,,1 Tablf'_' __ n •• n 85 Annex II. Lis! of Additional Figures •• n.n 102 Annex III, Acronyms. n. nn.110 List of Figures Fig. 1 Location map of the WACAF coastal countries 00 ...3 Fig. 2 West and Central Africa major surface currents. 00 .00.. 5 Fig. 3 OceanogrEphiC features and coastal resources in WACAF Region .,.7 Fig.4 Major induslri~1 pollutants in the West and Central Afric~n Region. • •• nn 000000008 Fig 5 Port approach high risk zones . ,..14 Fig. 6 Lccatlcn ofC6te d'woire coastal zOne .. ,.....,.,30 Fig, 7 Localion of the Coastal Zone of Gambia 0000 .. 36 Fig. 8 Sampling points along the Estuary ofGsmbia ,.,...,.,37 Fig, 9 Map of tho coastal zone of Ghana ...,.,...".,... Fig ga The Guinean Coastline. .00 ... 45 Fig, 9b The mangroves of Guinea with their mountain and marine context. .,.,....,.,.,.,.,. ,.,.,.,."...".....46 Fig. gc Coastal retreatr on the west side of Camayenne Peninsula - 240m (1947_1974) . .. 47 Fig. 10 Geological map of the Nigerian coastal zone .. .. 57 Fig. 11 The Nigerian ooastal zane and important coastal towns and SBttlements 00 ..,.,...,..,58 Fig. 12 Map of the Lagos Lagoon .......59 Fig. 13 Oil fields and crude oil pipelines in Nigeria Fig. 14 Map of the location 01 Senegal coastal zone .. ." ,.,.,...74 Fig. 15 Sampling points map for Senegal.,..,..,.,.,.".,.,. Fig. 16 NilrdltJs luad in SOrn~ groundwater wells around DakarlSuburban area List of Tables Table 1 Estimated amount of municipal sewage in comparison with industrial pollution in the WACAF Region. ,., ..,.".,.,.,.,.,."..... ,."..,.,.,.,.,6 Table 20 Results of faecal ooliform counts obtained from various sampling points along the Gambia estuary.. .,...".,..."".,.,.,.,.".,.,.,...,..... ,,,.,.,.,.,, ...,,....,37 Table 25 Microbiological propertiss "r waler samples ol>tainedfrom Lagos Lagoon .....,.....,." Tal>le 33 Bacteriological contamination of the waters around Dakar __ .".,.,."..." ......,,74 Preface The Global Programme of Action (GPA) for the Protection of the Marine Environment from Land­ based Activities (UNEP (OCA)ILBA'lG. 217) was adopted by an intergovernmentat conference held in Washington, DC" from 23 Odober to 3 November 1995, The goal of the Global Programme of Action is to prevent degradation of the marine environment from tand-based acliv~ies, by fecililating the reatisation by States of their duty to preserve and protect the marine environment. The Washington Conference designated tho United Nations Environment Programme (UNEP) as Secretariat of the Gtobal Programme of Action and requested that, as co_ordinator and catalyst of environmental activities within the United Nations system and beyond, tt should through its programmes and secretariat rote: (a) Promoteand fadlitate implementation of the programme ofAction at the naucnauevek (b) Promote and facilitate implementation at the regional, including sub-regional tevel through, in particular a revitalisation of the UNEP regiunal seas programme; and (e) Playa catalytic role in the implementation at the international level with other organisations and institutions. The present overview was commissioned by the Co-ordination Office of lhe GPA in eo-operation with the Regional Co-ordinating Unit (RCU) of the West and Central Africa Aelion Plan (WACAFIRCU) to assist the countries of the West and Central African region in their efforts to proteel the marine environment and achieve sustainable development. This overview will also be used to provide data and information for a global review on land-based sources and activities affeeling the quality of the marine, ooastel and aS80dated freshwater environment. currently being prepared (under the leadership of UNEP) by the working group in Marjne Environmental Assessments of the Joint Group of Experts of the ScientifiG A,peels of Marine Environmental Protection {GESAMP). The present overview identifies and aSsesses the problems related to land· based aciivities rorcountries for which information was found and the region as a whole. Executive Summary This doCtlmenl provkJes a regional oven/lew Dn land-based sources ;md acnvmss affect'lng the marine, coastal and associated rresrwater environment in the West and Central African region. It addresses natural condffions and processes, anthrop~enic impacts and ils sucio-€cQJlDmic implications, including losscs of cultural herjtage snes. This overview also contains information on emerging and forseeabje problems in the rogion, proposing priorities fur action including regional and internatiOllal ectlvltes fur cooperation. This cocument encompasses the following nations; Angola, Benin, Chad, Congo (Democratic Republic), C~te d'ivoire, Gambia, Ghana, Guinea, GUinea-Bissau, Uberia, Mauri1ania, Nigeria, Sao Tome and Principoe, Senegal and Togo. In summary, information received from various WACAF oounlfies and obtained from a number 01 other sources shows tha! the major issu"" related to lhe marine, coastal and associated freshwater environment pollution in the region include; (a) The decline of water quality, due to land-based human activities, SUCll as lhe introduction of sewage and waste watcr /rom industrial, domeslic and agricultural run off as weli as coastal urbaniLatilJl1; (b) Physical degradation and habilal modification; and (e) Fishery resources deplelion and the loss of mm;no biodiversity The sccto-eccnomlc and cultural implications can be tremendous in tenns of income reduction arising from a loss of fisheries stocks and c.a1chas, recreation and tourism amenHies, increase 01 waler lreatment and coesat ~rol8ction costs. Because