# 3.2. Lethal temperature and salinity¶

In Ichthyop, there is the possibility to define a range of temperature and salinity beyond which the particle is killed.

## 3.2.1. Lethal temperature¶

The functionning og the lethal temperature module depends on whether the growth module is enabled or not.

### 3.2.1.1. Growth disabled¶

lethal temperature can either be provided in a CSV file (lethal_temp_file parameter), which provides the lower and upper temperature values that can be supported by the particle as a function of age (in hours). The file must have the following format:

Time(hour);Cold temperature (C);Warm temperature (C)
0;14;22
48;13;22
96;12;22


In this case, three age classes will be considered: $$[0, 48[$$, $$[48, 96[$$ and $$[96, \infty[$$

If the lethal_temp_file parameter is not defined, single values will be used independently of the age. These values are provided in the cold_lethal_salinity_egg and warm_lethal_salinity_egg parameters.

Note that the temperature_field parameter, providing the name of the temperature variable, must also be provided.

### 3.2.1.2. Growth enabled¶

If the growth module is enabled, two cold and warm lethal temperatures must be provided. One for eggs (cold_lethal_temperature_egg and hot_lethal_temperature_egg), one for larva (cold_lethal_temperature_larva and hot_lethal_temperature_larva).

The stage (egg or larva) is determined by the growth module, and the right temperature range is applied to the particle.

## 3.2.2. Lethal salinity¶

Lethal salinity can either be provided in a CSV file (lethal_salt_file parameter), which provides the lower and upper salinity values that can be supported by the particle as a function of age (in hours). The file must have the following format:

Time(hour);Fresh salinity (PSU);Salty salinity (PSU)
0;35;40
48;30;40
96;30;45


In this case, three age classes will be considered: $$[0, 48[$$, $$[48, 96[$$ and $$[96, \infty[$$

If the lethal_salt_file parameter is not defined, single values will be used independently of the age. These values are provided in the fresh_lethal_salinity_egg and saline_lethal_salinity_egg parameters.

Note that the salinity_field_ parameter, providing the name of the salinity variable, must also be provided.