Aquatic pathogens are microorganisms, such as bacteria, viruses, fungi, and parasites, that can cause diseases in aquatic organisms like fish, amphibians, and invertebrates. These pathogens can thrive in various water environments, including oceans, rivers, and lakes, and can spread rapidly, affecting entire populations. The presence of aquatic pathogens can have significant impacts on ecosystems and fisheries. For example, diseases caused by Ichthyophthirius multifiliis, a protozoan parasite, can lead to high mortality rates in fish populations. Monitoring and managing these pathogens is crucial for maintaining healthy aquatic ecosystems and supporting aquaculture industries.