Fishing statistics from the Portuguese National Statistics Institute showed that restrictions on fishing also boosted the demand for other species such as mackerel, which was the fish that was most captured last year in Portugal. Sardines last year sold at an average price of €2.19 a kilo, the highest in 20 years because of a lack of fish being captured. And with quotas slashed by 90 percent this year, the prices are expected to sky-rocket.