Pollution Management in Lagoon

Dr . Ralph C. Nwaokoro Department of Marine sciences, University of Lagos, Nigeria (Unilag ) Introduction

The Lagos lagoon with an area of 208km 2 is largest of the lagoon systems of the West African sub-region . The Lagoon empties into the Atlantic Ocean through the Lagos Harbour , and receives freshwater from and Epe lagoons, Majidun, Agboyi and Ogudu creeks as well as the Ogun River It is extensively polluted along its length with substances like: • petroleum products from tank farms in area • washings from tankers and ships • waste products from industries • waste heat from cooling waters of Ijora Power plants • untreated sewage discharge • sawdust from sawmills located along the lagoon Current Situation in Lagos Lagoon

• About 80-85% of the industries in Nigeria are located in and they all discharge their effluents into the Lagos lagoon. • The effluents discharged are mainly untreated, while very few industries have any treatment plants. The Lagos lagoon consists of three (3) • main segments - namely the Lagos Harbour Segment, the Metropolitan and the Epe Division Segment. Main segments of the Lagos Harbour Current Problems

• The Lagos lagoon has supported decades of small scale fisheries which have shown signs of continuous decline • The Lagoon has become a sink for both Industrial and domestic wastes Inland Sources of Pollutants to the Lagoon

• about 2000 medium and large scale industries in Lagos that were discharging effluents directly or indirectly into the lagoon. • The Agbara Industrial estate in Ogun State discharges into the Ologe lagoon which is connected to the Lagos lagoon and harbour through small creeks and the Badagry creek. Industries discharging untreated effluent into the lagoon Research Efforts to Build Capacity to Tackle Problem • 2 Ph.D Students from NIOMR • 8 M.Sc Students (3 from NIOMR) Marine pollution-4 M.Sc Students The most common pollutants in Lagos Lagoon

Common pollutants in Lagos Researchers who Levels Main Locations S/N Lagoon have worked on them detected found

1 Petroleum Products Osibanjo (1983) 0.2-17.6mg/l Tin Can Island, Ijora, Amund (2000) Iddo 2 Untreated Sewage Akpata & Ekundayo 26m litres Iddo, Mende (1978) (Maryland) 3 Heavy Metals Ajao (1990), Chukwu (1991) ? Soyinka (2010) 4 Sawdust Akpata (2002) Okobaba, Ebute Nwaokoro (2010) Metta shores 5 Insecticides (Organochlorines Don-Pedro (1994) 0.44- ? e.g DDT, aldrin, dieldrin, 5.03mg/l lindane & endrin) 6 Bacterial Pathogens Akpata (1986) Iddo 7 Detergents & Industrial effluents Ajao (1990), Oyewo (1996) Nwaokoro (1997) Agboyi Creek PHCN Workshop with obsolete transformers containing PCBs The installation at Ijora causeway with transformer oil leakage directly into the lagoon. Lagos Lagoon is at the background Recent Observations

• Heavy metals such as cadmium, manganese, zinc, lead, iron and nickel were found in sediments and fish and fish eggs in the Lagos lagoon like Mugil cephalus (Grey mullet) • Most of the industries discharge priority pollutants like the metals, organochlorine pesticides (OCPs) and Polychlorinated biphenyls (PCBs) which have shown to accumulate in fish tissues ( Ethmalosa fimbriata -Bonga fish, Chrysichthys nigrodigitatus -catfish and Tilapia zilli-red tilapia), dioxins and other forms of POPs into the lagoon which may eventually be bio-accumulated and biomagnified along the food chain. • There is a general reduction in the biological diversity of organisms found in the lagoon Information Management and database Approach using GIS • Collaboration with the Gulf of Guinea Large Marine Ecosystem (GGLME) Project centre based at Unilag • Department of Geography, Unilag • Department of Surveying & Geoinformatics • NIOMR • Lagos State Government Goal • To develop a holistic approach by integrating the discrete data in the hands of individual researchers into a database for monitoring coastal waters in terms of pollution and biological diversity • Convert the available data into a tool for planning & prediction Data Integration Using GIS

Generic Specific Convertible data information

Planning tool For management Areas of Need

• More Collaboration • Capacity building • Equipment Thank You