I'm excited to read this series. 

I remember trying (very briefly) to look into what ecosystem services are thought to be most important, and personally I failed to find a justification for the very strong claims you see about them, such as being crucial to survival and so on. For example, if insects disappeared, it seems like we would survive fine on wind-pollinated crops. I came away suspecting motivated reasoning due to people liking "nature" for other reasons. 

But I wasn't able to come to any confident conclusion, so I'm looking forward to finding out what yours was! Very much a topic that could benefit from a critical approach; there seem to be quite a lot of aspects to disentangle. 

There are two UK government consultations closing March 9th, for: (1) banning cages for 7 million hens, and (2) reducing the pain that castration and tail docking practices for lambs cause, such as requiring pain relief. In the UK are 7 million hens (21%) still in cages, and roughly 17 million lambs that go through these painful procedures every year. 

You can use these guides to make your response, to make these changes more likely to happen: 
Hens: https://tinyurl.com/cage-consultation 
Lambs: https://tinyurl.com/lamb-consultation 

If you prefer, you can sign up for this online event on Sunday 5pm-6pm UTC, where we'll be writing and submitting our responses together. 

Hi, was this study published?

Net negative because it is a true statement? Or some other reason?

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

Show all footnotes

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.