Many fish eaten as seafood are bred and raised in fish farms. The fish on a farm can be infected by parasites called sea lice: small crustaceans that feed on a fish’s blood and skin, which may injure or even kill the fish.
Jansen and colleagues (2012) analyzed sea lice infections on trout and salmon farms. They used data reported by many fish farms on the numbers of sea lice found on their fish. The scientists compared the number of sea lice with the “local farmed fish biomass density,” which is a measure of population density that accounts for both the number and biomass (or size) of fish on a farm.
The effect of local farmed fish biomass density on the counts (numbers) of sea lice per fish
Each point represents the mean fish density and sea lice count for a group of farms in a specific year.
Use what you've learned above to answer the following questions: