According to the passage, pollution seems to be the reason behind the decline in the population of sea otters. However, the speaker in the lecture says that it is not the pollution but predation by the Orca that is the main cause for the decline in the sea otter population. In the lecture, the speaker gives the following reasons to prove this conclusion.
First, in the lecture it is mentioned that if the reason behind the decline in sea otter population as pollution then it would be easy to spot the dead sea otter washed along the coast. She states that, if there was a decrease in sea otters' resistance to life threatening infection as written in the passage then they would have died and there bodies would have been taken to the shore by the ocean. However, no dead bodies of sea otters are found and so this strengthens her point that it was not the pollution that killed sea otters.
Second, according to the lecture, there is a decline in the whale population that orca prey upon due to hunting. As a result, orca will have to change their prey in order to survive. In such an instance, orca may have begin to prey upon smaller sea mammals such as sea otter, seals and sea lions. This has resulted in the decline in the population of all these species of sea mammals. Thus, it is the predation and not the pollution that is causing the decline in the sea otter population.
Third, the speaker says that it is the predation that is a more likely explaination than pollution behind the uneven pattern of decline in the sea otter population at some Alaskan locations. She mentions that the sea otter population has stayed stable in shallow and rocky areas while it has decreased in the other areas. She says that it is difficult for the orca's to hunt sea otters in such shallow and rocky areas and so their population has stayed stable. On the other hand, in other areas sea otter may be an easy prey and so their population is declining.
Therefore, in the lecture it is concluded that it is the predation of sea otters by the orcas that is causing the decline in their population instead of pollution.
Grammar and spelling errors:
Line 3, column 235, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'otters'' or 'otter's'?
Suggestion: otters'; otter's
...es that, if there was a decrease in sea otters resistance to life threatening infectio...
^^^^^^
Line 5, column 219, Rule ID: HAVE_PART_AGREEMENT[1]
Message: Use past participle here: 'begun'.
Suggestion: begun
...ive. In such an instance, orca may have begin to prey upon smaller sea mammals such a...
^^^^^
Transition Words or Phrases used:
but, first, however, if, may, second, so, then, therefore, third, thus, while, as to, such as, as a result, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 20.0 10.4613686534 191% => OK
Auxiliary verbs: 6.0 5.04856512141 119% => OK
Conjunction : 9.0 7.30242825607 123% => OK
Relative clauses : 14.0 12.0772626932 116% => OK
Pronoun: 37.0 22.412803532 165% => Less pronouns wanted
Preposition: 51.0 30.3222958057 168% => OK
Nominalization: 26.0 5.01324503311 519% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1744.0 1373.03311258 127% => OK
No of words: 383.0 270.72406181 141% => Less content wanted.
Chars per words: 4.55352480418 5.08290768461 90% => OK
Fourth root words length: 4.42384287591 4.04702891845 109% => OK
Word Length SD: 2.43115853152 2.5805825403 94% => OK
Unique words: 144.0 145.348785872 99% => OK
Unique words percentage: 0.375979112272 0.540411800872 70% => More unique words wanted or less content wanted.
syllable_count: 547.2 419.366225166 130% => OK
avg_syllables_per_word: 1.4 1.55342163355 90% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 5.0 3.25607064018 154% => OK
Article: 3.0 8.23620309051 36% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 8.0 2.5761589404 311% => Less preposition wanted as sentence beginnings.
Performance on sentences:
How many sentences: 16.0 13.0662251656 122% => OK
Sentence length: 23.0 21.2450331126 108% => OK
Sentence length SD: 40.5095956997 49.2860985944 82% => OK
Chars per sentence: 109.0 110.228320801 99% => OK
Words per sentence: 23.9375 21.698381199 110% => OK
Discourse Markers: 7.8125 7.06452816374 111% => OK
Paragraphs: 5.0 4.09492273731 122% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 10.0 4.27373068433 234% => Less facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.340421587271 0.272083759551 125% => OK
Sentence topic coherence: 0.142630907301 0.0996497079465 143% => OK
Sentence topic coherence SD: 0.0793224915854 0.0662205650399 120% => OK
Paragraph topic coherence: 0.218993717338 0.162205337803 135% => OK
Paragraph topic coherence SD: 0.0312553696241 0.0443174109184 71% => OK
Essay readability:
automated_readability_index: 12.0 13.3589403974 90% => Automated_readability_index is low.
flesch_reading_ease: 65.05 53.8541721854 121% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.9 11.0289183223 90% => OK
coleman_liau_index: 9.41 12.2367328918 77% => OK
dale_chall_readability_score: 7.17 8.42419426049 85% => OK
difficult_words: 58.0 63.6247240618 91% => OK
linsear_write_formula: 13.5 10.7273730684 126% => OK
gunning_fog: 11.2 10.498013245 107% => OK
text_standard: 12.0 11.2008830022 107% => OK
What are above readability scores?
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Write the essay in 20 minutes.
Rates: 73.3333333333 out of 100
Scores by essay e-grader: 22.0 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.