The starfish are used as a source of lime by farmers in areas where limestone is unavailable. 4,000 tons of the animals are used annually for this purpose. This trade is often carried out with shellfish farmers, for whom the starfish pose a major irritation by eating their stocks. The economic impact of starfish is primarily local. Around 50,000 tons of sea urchins are captured each year. They are which are consumed particularly in Japan, Peru and in France.