Final answer:
Mortality is not the sole determinant of AIS severity as factors like pathogens and environmental conditions also play a role. AIS affected populations can experience patchy mortalities and may see temporary setbacks followed by recovery.
Step-by-step explanation:
Mortality is not the sole determinant of AIS severity. While mortality rates can vary depending on various factors, including pathogens and environmental conditions, other factors also contribute to the severity of Acute Infectious Salmon Anemia (AIS). A study conducted in Sweden found that mortalities in AIS affected populations were patchy and did not follow the typical herpes-related mortality pattern in Europe. Additionally, large unaffected oyster populations in Scandinavia suggest that AIS may cause temporary setbacks followed by recovery.