Fish Farmer

I’m an evil aquacultur­e scientist

e are still ot etti our essa e across about far ed fish

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I m an evil a uaculture scientist it must be true because I was once called it at a public meeting. Why I was simply presenting some research on sea lice that didn t fit the theoretica­l models that all sea lice come from farmed fish and infect wild fish.

In fact, the data was pretty clear cut and showed that farmed smolts going from freshwater, where sea lice cannot live, into the ocean, where sea lice are common, catch sea lice from wild fish.

These pioneering sea lice come from the resident wild salmonids in the area. Thus wild fish actually infect farmed fish.

The problem was that the person who heckled me during my presentati­on was not well informed on the subject, believing a commonly held public perception that was being proposed in grey literature and anti-a uaculture websites that the sea lice problem always comes from farmed fish.

Sadly, it is much more complicate­d than that. It is inconceiva­ble that there is not a farmed-wild fish interactio­n going on. However, the research that supports the farmed to wild fish hypothesis is not comprehens­ive. It o en relies on mathematic­al models that make huge assumption­s about the biology of sea lice, o en treating them as inert particles that dri passively in the ocean.

They are not inert particles, but living animals that want to find a host, age, become senile, die, get eaten and so on.

The problem is that it is di cult to get the biological data from the ocean to validate the mathematic­al models. Sea lice are tiny, hard to catch and identify and this research is challengin­g to do. Yet mathematic modelling is relatively cheap a computer, a scientist and some so ware and the research can start.

The biologist needs boats, some way of catching sea lice, then accurately identifyin­g them usually by expensive molecular tests and it takes at least a year to check for seasonal variations.

So we have a dilemma unverified computer models can e ectively put in any set of variables

 ??  ?? Left: Figure 1 Antibiotic use in Norway from 1970-1990s
Left: Figure 1 Antibiotic use in Norway from 1970-1990s

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