declined similarly from a peak of 535,000 tonnes in 1979, to 286,000 in 1986, but over the same period, trawler numbers increased from 92 in 1979, to 440 in 1989. Also, the mean length of trawled fish has declined between 1981 and 1990, for example, as follows:
| Length in cms | 1981 | 1991 |
| Croaker | 32.32 | 26.41 |
| Soles | 32.88 | 25.47 |
| Threadfin | 24.08 | 20.81 |
It is interesting that fishermen from Ondo State have been moving into the Niger Delta because they cannot compete with Lagos trawlers. But the trawlers have been following them, resulting in confrontation with local fishermen.
A 1980 to 1989 survey (Nigerian Federal Department of Fisheries Statistics 2nd Edition) of trawler catches brought to Lagos showed the following worrying average, as annual tonnes per trawler of specific fish caught (sample figures only):
| Tonnes/Trawler | 1980 | 1985 | 1989 |
| Croaker | 739 | 403 | 52 |
| Soles | 82 | 89 | 19 |
| Catfish | 218 | 3 | 0 |
| Snappers | 105 | 27 | 16 |
| Barrracuda | 159 | 21 | 7 |
11.4.5 THE FUTURE OF THE FISHING INDUSTRY
The Niger Delta and national fish catches are declining, and the only option for Nigeria's future fishing industry has four necessary and interdependent parts:
- A limitation of marine fishing.
- Maintenance of the mangrove forests as the foundation of the fish life cycle.
- Increased fish farming in the Fresh-water ecozone.
- Increased fish farming in the Brackish-water ecozone, without compromising its vital place in initiating the marine food chain.
In the fresh-water ecozones fish farms can be encouraged on a small-scale, which can be maintained by a single family. The fish can be fed on household waste, rats, lizards, fish intestines, poultry manure and easily grown crops such as Plantains, Papaya and Cassava. What is needed is a secure supply of young fish, (fingerlings).
Because of the high level of nutrients in the water, mangrove environments are ideal for farming fish in cages, enclosures and ponds. Nonetheless large areas of mangroves have been destroyed in Southeast Asia for Prawn and Shell fish farms, and similar activity in the Niger Delta would be counter productive in relation to deep-sea, inshore and estuarine fishing. However the nutrient rich environment can be used to increase the national fish yield by raising of fingerlings in ponds to be released into the creeks; rather in the manner of seeding mountain streams with trout.
