Some good news since this post was written a few years ago: the usage of cleaner fish in Norway has declined from a peak of 60 million in 2019 to 24 million in 2024.^[1] From what I've read this seems to be due to both pressure from the media and Norwegian authorities^[2] and also growing use of other methods like laser delousing, which showed positive results in a recent study.^[3] (I wasn't able to tell how important each factor was in causing this decline.)

More good news is that the country with the second largest salmon industry, Chile, has not started using cleaner fish:

• The species used in Norway are banned in Chile because they're not native there.^[4] 
• It was reported in 2018 that species native to Chile were being trialed use on Chilean salmon farms.^[5] 
• However, a 2023 article says “In both cases, preliminary trials [2015-2019] have been unsuccessful”.^[6]

1. ^{^}

   Rethink Priorities, 21 November 2025: Mapping salmon welfare: sea lice treatments. (Thanks to @Hannah McKay🔸 and @Sagar K Shah for your work.)

2. ^{^}

   For example "The Norwegian Council for Animal Ethics [an independent advisory body] has stated that continuing the use of cleaner-fish is not justifiable." (from the Norwegian Veterinary Authority Fish Health Report 2024, p. 96.), or public criticism from the Norwegian Food Safety Authority. 

3. ^{^}

   Fishfarmingexpert, 1 September 2025: Significantly fewer treatments needed at farms with lice lasers. The study says "Sites with optical delousing used on average fewer cleaner fish." You can see what the laser system looks like in operation in this video. 

^{^}

Thefishsite, 30 Nov 2018

^{^}

Sánchez et al, 2018: The Patagonian blenny (Eleginops maclovinus): a Chilean native fish with potential to control sea lice (Caligus rogercresseyi) infestations in salmonids

^{^}

Bravo and Treasurer, 2023: The management of the sea lice in Chile: A review

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Centre for Wild Animal Welfare (and the EA Animal Welfare Fund earlier this year)

When people write about where they donate, aren’t they implicitly giving a ranking? 

Is there a way to donate that lets UK donors claim Gift Aid? Your page at every.org doesn’t seem to have this (though I like the built-in ability for supporters to start a fundraiser). 

In its current form, Arthropoda costs about $175K per year […] We’re about $55K short for 2026

 A possibly naive question — does this mean:

1. Arthropoda needs $55k to remain at the same level of funding (inflation-adjusted) as 2025?
2. Or that Arthropoda needs $55k to fulfil its 2026 plan, which may involve an increase (or decrease) in funding?
3. Or is $55k the overall “room for more funding” in some other sense?  
    

The ban on fur farming in the UK [...] didn’t lead to an increase in imports for fur

There's some data from the ONS on this, graph below. Here's the fur data separately (see the "Whole world" row). The ban took effect on 1 Jan 2003. So this seems to be true, although I guess demand for fur was already falling. 

Interesting. Then I guess strictly speaking it makes more sense to speak only of the welfare footprint of products, rather than of a whole person's carbon footprint, unlike how we speak of both products and people having carbon footprints. 

Potential opportunity to influence the World Bank away from financing factory farms: The UK Parliament is currently holding an open consultation on the future of UK aid and development assistance, closing on November 14, 2025. It includes the question, "Where is reform needed in multilateral agencies and development banks the UK is a member of, and funds?". This would include the World Bank, which finances factory farms,^[1][2] so could this consultation be a way to push it away from doing that, via the UK government? 

Are any organisations planning on submitting responses? If so, should there be an effort to co-ordinate more responses on this?

1. ^{^}

    "Why the World Bank Must Stop Funding Factory Farms", 30 Apr 2024 https://www.worldanimalprotection.us/latest/blogs/why-the-world-bank-must-stop-funding-factory-farms/ 

2. ^{^}

   "The World Bank has a factory-farm climate problem", 20 Nov 2024 https://grist.org/food-and-agriculture/world-bank-development-banks-factory-farm-climate-industrial-agriculture/ 

Just listened to the first episode and thoroughly enjoyed it, you're very funny people (:

Yes, this is a good point -- perhaps you could speak of "the dairy industry's welfare footprint" if you sought to avoid this. 

Though I guess people could only support policy change that tried to, for example, reduce flying in favour of travel by train, if they are first aware of the differences in emissions (254g vs 6g per km apparently), rather than just being aware that both release some emissions -- and perhaps the idea of carbon footprints helped popularise that there are such big differences (?) 
But maybe there's something about the term "footprint" which is too closely tied to individual behaviour, and a better term could be found.