Integrated Tpo 65 (Tuna Fish Farming,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,)
Reading passage:
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 problems and criticisms.
First, female tuna do not lay eggs in captivity, so tuna farmers must capture large quantities of young wild tuna to stock their farms, further reducing wild tuna populations. These young tuna are caged and fed until they are large enough to be sold. Since the captured females in tuna farms cannot lay eggs to replace the tuna that are sold, tuna farmers continue to catch young wild tuna to keep their farms going and so worsen the decline in wild tuna populations.
Second, tuna raised on farms are very expensive because they depend on a costly, high-protein food derived from other fish. Tuna feed almost exclusively on small fish, which supply them with the proteins and nutrients they require. A single tuna can grow more than four meters long, weigh close to 700 kilograms, and eat 70 kilograms of food a day! It is unlikely that tuna farms can remain profitable while supplying so much expensive food for the tuna.
Third tuna confined to ocean cages are likely to become infested with parasites, organisms that feed on and weaken the animal they attach to. Tuna farmers off the coast of southern Australia have had problems with infestations of blood flukes, a type of parasite that lives within the blood vessels and heart of infected fish. Parasite infestations weaken tuna, slow their growth, and can even cause death, usually by making them susceptible to other diseases. Tuna farms in southern Australia have had 10 percent of their tuna die before they could be sold.
The article in the passage and topic in the listening section has opposing views about tune fish farming whether or not tuna fish farming has any negative problems. The author in Passage postulates that tuna fish farming faced several problems because female tuna cannot lay eggs, need high protein to increase growth rate, and has parasites effect on farms. On the other hand, the lecturer challenges the author’s claims by providing some solutions from the researchers and experts.
To begin with, according to the passage, tuna farmers have to capture a huge amount of wild young tuna population which further reduces the wild tuna population, as female tuna cannot lay eggs in captivity. However, Speaker in the lecture provides some examples of advanced research activities that can help farmers by giving eggs from female tuna. According to advanced research adding hormones in female tune can have the ability to lay eggs and there is no need to capture young wild tuna for farming.
The lecturer posits that there is cheap alternative high protein food like plants are available for farming tuna, so farmers do not depend on high costly high protein food from other fish. These reasons for the lecture weaken the author’s claims that tuna fish farming will not be profitable since farming requires a huge amount of money and fish proteins
Lastly, From the text, it is said that tuna fish farming has some challenges of parasite attacks as tuna have to confined in ocean cage for a long time. Plus, Author says that in many farm fish can become weaker, growth becomes slower as well as many fish dies due to parasite attack on blood vessels. But lecturer suggests that deep-water tuna fish farming will overcome these parasite problems infestations on blood flukes are less likely to occur in deep water further away from the seashore.
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