A knife cutting through food demonstrates the principle of which simple machine?

Nigeria has: artisanal fishing (traditional methods, small boats, coastal and inland), industrial fishing (trawlers, large-scale), and aquaculture (fish farming). Fish is major protein source.

Resources: Atlantic coast (marine), Niger Delta (brackish), rivers and lakes (freshwater), and man-made reservoirs. Fish species include tilapia, catfish, mackerel, croaker.

Challenges: overfishing depletes stocks, pollution damages habitats, illegal foreign trawlers, limited cold storage and processing. Aquaculture growing but needs investment. Imports fill domestic production gap.