Proportion of resistance in each scenario on the day of harvest in the final (10th) cycle.

<p>In each scenario there are 1500 farmed salmon.</p

Modelled lifecycle of <i>L</i>. <i>salmonis</i>.

<p>The statechart used in the model to track the lifecycle of the sea louse agents. During the <i>planktonic</i> stage the sea louse lives in the water column. During the <i>Chalimus</i>, <i>Pre-Adult</i>, and <i>Adult</i> stages, the sea louse is attached to a salmon host. Each stage has a different mortality rate. Treatments in the model only apply to sea lice in the attached stages.</p

Parameters for calculating developmental times for different stage in the sea louse life cycle.

<p>β₁ and β₂ are sampled from normal distributions. λ is the parameter for an exponential distribution. Where there is a range of values, the value used is randomly sampled from a uniform distribution over that range. Time in the Nauplii stage does not involve the term from the exponential distribution [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139128#pone.0139128.ref024" target="_blank">24</a>].</p

General model parameters.

<p>In some cases, we based these parameter values on research in the literature. These sources are noted in the table. In all other cases, the parameters are plausible values based on expert opinion within our group and are based on field and/or laboratory observations of different populations within the North Atlantic.</p

Number of Treatments for each cycle.

<p>The values shown are the average number of treatments for a cycle from 100 replications. Grey bars show 95% confidence intervals. Each line shows a different scenario. There is no fitness cost of resistance in these scenarios. Proportions of wild salmon to farmed salmon for each scenario are shown in the legend, e.g. 1:10 is 1 wild for every 10 farmed.</p

Reproduction and mating behaviour statecharts.

<p>Male and female sea lice have different reproductive and mating behaviours as reflected in these statecharts for the sea louse agents. These two statecharts come into effect when the sea louse agents reach the <i>Adult</i> state in their lifecycle. Males search for female mates, and if there are no mature females available they will guard <i>Pre-Adult</i> females until they are mature. While searching, there is a chance of dispersing to a different host. Females extrude egg strings, which are attached to them until hatching. There is a separate state for the first gravid period to reflect lower fecundity in the first egg clutch.</p

Proportion of resistant alleles in sea louse agent population for all scenarios.

<p>Top chart shows scenarios with no fitness cost and the bottom chart shows scenarios with a fitness cost of 1% per resistant allele. Lines show mean proportions of resistant alleles in the farm sea louse population based on 100 simulation replications. Grey bars indicate 95% confidence intervals. The white vertical “gaps” represent fallow periods. Proportions of wild salmon to farmed salmon for each scenario are shown in the legend, e.g. 1:10 is 1 wild for every 10 farmed.</p

Average adult sea lice per host per day for each cycle.

<p>Left chart shows the four scenarios with no fitness cost of resistance, the right chart shows the scenarios with a small fitness cost applied. Values are lice count per host per day averaged over the whole cycle (without fallow time) from 100 replications. Grey bars show 95% confidence interval. Note that the y-axis does not show zero. Proportions of wild salmon to farmed salmon for each scenario are shown in the legend, e.g. 1:10 is 1 wild for every 10 farmed.</p

Daily sea louse mortality rates by stage-sex combination.

<p>Where there is a range of values, an individual's rate parameter is sampled from a uniform distribution over that range. All values are from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139128#pone.0139128.ref024" target="_blank">24</a>]</p

Motile population proportion chart from Managing aquatic parasites for reduced drug resistance: lessons from the land

Proportion of motiles in the total population over each cycle for each scenario