Another severe case of Bolted-on Tone of Voice Syndrome.I'm sure sustainable fishing is a good thing, even if I'm not entirely clear what it involves. But I strongly object to the way Britain's Best Loved Retailer is telling us about it, for two reasons - the first of which may sound pedantic.
The idiom is used incorrectly. You don't believe something hook, line and sinker; you fall for it. The associations conjured up by the phrase are all to do with with naivety or gullibility. And, actually, that isn't a niggly, nitpicking objection: the familiar but misapplied phrase undermines the intended sincerity of the communication.
My second, more obvious cause for complaint is the complete redundancy of the second sentence. I suspect the brand communications team responsible would defend it on the grounds that it makes a dry, factual piece of information more engaging, by addressing the reader in a tone of voice appropriate to Britain's Best Loved Retailer.
But does it, really? Or is it just a laboured play on words that adds nothing but an air of facetious self-congratulation? You decide.