寿司粉注意啦！海水升温或推高寿司价格

Sushi prices in restaurants and supermarkets are tipped to soar after a sharp increase in one of the key costs of creating the Japanese dish.

A large proportion of sushi, which combines raw fish or vegetables with cooked vinegared rice, contains farmed shrimp, prawns or salmon.

The cost of the main feed for farmed fish has jumped by almost 50 percent in two weeks to reach a record high, according to reports.

The feed, called fishmeal, is a brown powder made from dried fish bones and the trimmings of small marine species such as anchovies.

Rising sea temperatures led to a drop in anchovy catches in Peru, the world's largest exporter, pushing up prices. A tonne of fishmeal now costs $2,500, according to the Financial Times, up from $1,689 at the end of October.

Fishmeal prices have risen fourfold in a decade due to climate change and increased demand, with around four per cent more farmed fish being eaten every year.

The increased costs are expected to be passed on to diners as restaurants and cafés serving sushi put up prices to maintain their margins.

The most popular sushi consist of raw, prawns, salmon and shrimp and rice. Most of the raw fish is farmed.

The growth of sushi, which has become fashionable in Britain and other western nations over the past few years, and the general popularity of fish this year led to global farmed fish consumption surpassing that of "captured" fish for the first time.