Wild tuna a species of large ocean fish have decreased in number because of overfishing Recently attempts have been made to farm tuna by feeding the fish in ocean cages until they become large enough for sale However tuna farming has faced several problem

In this set of materials, the reading passage claims that the population of wild tuna has been decreased recently due to overfishing, and scientists state several criticisms about farming tuna. However, the lecturer asserts some promising solutions to address all concerns and explains her evidence. First of all, it is mentioned in the passage that female tuna cannot lay eggs when they are in cages. In contrast, the professor points out that certain hormones help female tuna to reproduce efficiently, and researchers inject them directly to their bodies, while they do not cause any harm for fishes and consumer later. She believes that this breakthrough discovery can solve this problem, which prevents the population decline. Hence, female fishes still can produce more young tuna, even in captivity. Furthermore, the author of the passage argues that tuna feed on high-protein food derived from other fish, which are costly for farmers. Conversely, the lecturer refutes the former notion and believes that unlike what was stated in the article, they can eat plants that are high in protein as well, and it is not necessary to exclusively consume small fishes to grow. Moreover, those specific plants are inexpensive and affordable, and farmers still have a profitable business. Therefore, farmers have an alternative way to reduce the cost of growing tuna. Finally, the reading explains that tuna confined to ocean cages are susceptible to become infested with parasites. On the contrary, the professor states that farmers can move the cages to deeper parts of the ocean because blood flukes, a parasite that lives in the blood vessels, like to live close to shore and cannot survive in deeper zones. In fact, if farmers transfer tuna to safer areas, they can basically stop infestations of blood flukes and increase the population of alive tuna.