Low FCR efficient scenarios

[gclawson1]

In our meeting yesterday, we decided to add another scenario in which there are efficient FCRs. What I'm imagining is to have these 4 scenarios to compare:

• Plant-dominant formulation; current day FCR (already have this)
• Fish-dominant formulation; current day FCR (already have this)
• Plant-dominant formulation efficient FCR
• Fish-dominant formulation efficient FCR

So the question is, what do we assume the efficient FCR to be? Should I assume it to be the lowest FCR we currently use (1, like for Norway)?

Here is the current data I am using, derived from Tacon and Metian, what you originally used:

One question about this, I use the eFCR_min variable to calculate the feed demand. This means that any of the countries not listed there get an eFCR_min of 1... should I adjust that to be 1.2, like you've done in your paper, Rich? 1 seems like a very efficient ratio to use for all other countries... Or should I use the mean instead?

[gclawson1]

Correction: I am using the global average, 1.3, for all other countries not listed above

[gclawson1]

Also, found a minor problem with my code (stupid joining and trailing spaces), I was slightly overestimating feed demand in some countries, so it's good I'm looking over this again!

[cottrellr]

We could do one of a few of things. We could:

• arbitrarily adjust the FCR to be, for instance, top of my head, 10% lower.
• use literature to inform the efficiency gains that could be expected
• the above two could be applied globally - OR we could focus on key countries and what efficiency gains in those countries could do for shifting the needle for the whole industry? This could be arbitrary or literature.

I would favour being informed to some extent by literature, but arbitrary changes could also be aspirational. I think a really interesting question is what change in efficiency yields the same net benefit of changing diets (across all species not worrying too much about which species and where).

[gclawson1]

Do you (@cottrellr) have any papers that we could use to inform? Maybe that discuss the future salmon aquaculture and its efficiency or how it's changed? I've started looking into some below:

Tacon & Metian 2008

• Calculation of pelagic forage fish input per unit of farmed fish or crustacean output showed steadily decreasing fish-in fish-out ratios for all cultivated species, with decreases being most dramatic for carnivorous fish species such as salmon (decreasing from 7.5 to 4.9 from 1995 to 2006)
  • Not FCR exactly, but still useful info.

Iversen et al. 2020: https://www.researchgate.net/publication/339220299_Production_cost_and_competitiveness_in_major_salmon_farming_countries_2003-2018

Ytrestøyl et al. 2015: https://doi.org/10.1016/j.aquaculture.2015.06.023

• If we assume this is correlated with FCR, could use these trends somehow

Sarker et al. 2013: https://onlinelibrary.wiley.com/doi/epdf/10.1111/raq.12013?saml_referrer

• "Using updated information regarding domestic aquafeedsthis review reports advances that have been made in diet formulation, fish in–fishout (FIFO) and feed conversion ratios (FCR) and demonstrates that productionefficiency of farmed salmonids has significantly improved over time due to con-tinued innovations in the aquafeed sector. The results suggest that the Canadiansalmon aquaculture industry efficiently converts wild fish resources into high-value fish products."
• " In the 1970s and early 1980s, feed conversion ratios(FCRs; feed: gain) of 2–2.5 were common for marketablesize rainbow trout (400 g
  1kg) fed commercial feeds(steam-pelleted feeds). Today, the use of more highly digestible nutrient-densityextruded feeds (e.g. 46–50% protein, 20–24% fat) allowscommercial farmers to achieve an FCR of about 0.9–1.2 forrainbow trout growing to market size (average around1 kg; Corey Feed Mills Ltd, 2010, NB, Canada)"
• The calculations in this paper assume an FCR of 1.2 for other countries.

Naylor et al. 2009: https://doi.org/10.1073/pnas.0905235106

• 1995 average FCR 1.5; 2007 average FCR 1.3
• FCRs in 2006 ranged from 1.0 to 1.6 for salmon
• Salmon FCRs are highly sensitive to changes in the amount of fish oil included in feeds