The average UK household spent £190 this year on ethical food and drink, up 17% on last year, according to the Co-operative Bank's latest Ethical Consumerism report.
The value of the ethical food and drink sector rose from £4.1bn to £4.8bn - the biggest growth registered by any ethical category.
Sustainable fish sales rose 224% following the introduction of new lines by manufacturers and retailers.
Sales of Fairtrade goods, such as tea, coffee and bananas, grew by 46%, increasing from £195m to £285m.
This was driven by increased consumer awareness of the Fairtrade mark, which is now recognised by almost three in five shoppers, and greater availability of products, said the report.
Households also spent £213 on ethical non food products annually.
Sales of energy-efficient light bulbs increased by 44%, mainly due to a reduction in their price differential with regular light bulbs.
Overall, said the report, household expenditure on ethical goods and services had almost doubled in the past five years, with yearly spending now £664 compared with £366 in 2002.
The overall UK ethical market is now worth £32.3bn a year, up 9% from £29.7bn in the previous 12 months.