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.
In the reading passage, the author concentrates on several problems against farming tuna, a species of large ocean fish, in captivity. However, the lecturer casts doubt on these criticisms and respectively points out the problems with all the author's assertions.
Firstly, the author argues that female tuna do not lay eggs in captivity, which means farmers should continue to replacing sold animals with new ones from the ocean. Nevertheless, the lecturer challenges this idea and states that researchers have found a certain hormone which can be injected into the female tuna's body to help them lay eggs in captivity without the need to introduce new wild fish. It means the wild tuna population can be preserved this way.
Secondly, the lecturer suggests that raised tuna are very expensive since their costly food should be derived from other fish. In contrast, the lecturer brings up the fact that tuna need high-protein diets which are basically produced from other fish. However, scientists have discovered a plant-based food which contains all the proteins tuna need and can replace the former one. Since the new food is inexpensive, the cost of bred tuna will keep low.
Lastly, the author asserts that bred tuna may be susceptible to infections caused by blood flukes, a type of parasite. Conversely, the lecturer refutes this claim and clarifies that some studies recently have been done on tuna located in South Australia and the results revealed that if the fish is kept deep in the water, blood flukes cannot survive. These parasites can only continue to live near the water surface. Thus, raising tuna in cages which are deep enough can be a promising solution.
Grammar and spelling errors:
Line 3, column 331, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'proteins'' or 'protein's'?
Suggestion: proteins'; protein's
...plant-based food which contains all the proteins tuna need and can replace the former on...
^^^^^^^^
Transition Words or Phrases used:
conversely, first, firstly, however, if, lastly, may, nevertheless, second, secondly, so, thus, in contrast
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 13.0 5.04856512141 257% => Less auxiliary verb wanted.
Conjunction : 5.0 7.30242825607 68% => OK
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 15.0 22.412803532 67% => OK
Preposition: 33.0 30.3222958057 109% => OK
Nominalization: 2.0 5.01324503311 40% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1404.0 1373.03311258 102% => OK
No of words: 276.0 270.72406181 102% => OK
Chars per words: 5.08695652174 5.08290768461 100% => OK
Fourth root words length: 4.07593519647 4.04702891845 101% => OK
Word Length SD: 2.53727721729 2.5805825403 98% => OK
Unique words: 164.0 145.348785872 113% => OK
Unique words percentage: 0.594202898551 0.540411800872 110% => OK
syllable_count: 430.2 419.366225166 103% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 11.0 8.23620309051 134% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 21.0 21.2450331126 99% => OK
Sentence length SD: 53.857581205 49.2860985944 109% => OK
Chars per sentence: 108.0 110.228320801 98% => OK
Words per sentence: 21.2307692308 21.698381199 98% => OK
Discourse Markers: 8.23076923077 7.06452816374 117% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 5.0 4.27373068433 117% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.28570742156 0.272083759551 105% => OK
Sentence topic coherence: 0.106096787387 0.0996497079465 106% => OK
Sentence topic coherence SD: 0.0844487848106 0.0662205650399 128% => OK
Paragraph topic coherence: 0.177060867596 0.162205337803 109% => OK
Paragraph topic coherence SD: 0.0375622018071 0.0443174109184 85% => OK
Essay readability:
automated_readability_index: 13.2 13.3589403974 99% => OK
flesch_reading_ease: 50.16 53.8541721854 93% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 11.5 11.0289183223 104% => OK
coleman_liau_index: 12.24 12.2367328918 100% => OK
dale_chall_readability_score: 9.08 8.42419426049 108% => OK
difficult_words: 77.0 63.6247240618 121% => OK
linsear_write_formula: 14.0 10.7273730684 131% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 14.0 11.2008830022 125% => OK
What are above readability scores?
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Rates: 90.0 out of 100
Scores by essay e-grader: 27.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.