Sea otters are a small mammal that lives in the waters along North America's west coast from California to Alaska. A few years ago some of the sea otter populations off of the Alaskan coast started to decline rapidly and raised several concerns because of their important role in the coastal ecosystem. Experts began investigating and came up with two possible explanations. One explanation was environmental pollution and the second was attacks by predators.
At first it seemed as if the pollution was the most likely cause for the population decline. One reason pollution was more likely was because of the known pollution sources along the Alaskan coast such as oil rigs. Also water samples taken in the area showed increased levels of chemicals that could decrease the otters' immune systems and indirectly result in their deaths.
Another thing that pointed to pollution as the culprit was the decline of other sea mammals such as seals in the same areas. This indicated that whatever was affecting the otters was also affecting the other sea mammals. Environmental pollution usually affects an entire ecosystem instead of just one species. Only predators that occurred in a large area, such as orcas (a large predatory whale), could cause the same effect, but they usually hunt larger prey.
Finally, scientists believed the pollution hypothesis would also explain the uneven pattern of otter decline. In some Alaskan locations the otter population declined greatly while other populations remained stable. Some experts suggested this could be explained by ocean currents, or other environmental factor, might have created uneven concentrations of pollutants along the coast.
Question:
Summarize the points made in the lecture and explain how the speaker casts doubt on specific points made in the reading passage.
The reading states that among environmental pollution or attacks by predators, the former is more likely the reason for decline of sea otters population and provides three reasons of support. However, the professor explains that the studies reveal that predators is the primary cause for decline in otter population and refutes each of the author's reasons.
First, the reading claims that the pollution from oil rigs and chemical industries caused decline in otter population by reducing resistance to life threatening infections. The professor refutes this point by saying that pollution has nothing to deal with population decline. According to the professor, if the pollution is the major cause then there must be evidences of dead otters washed upon shore. But, there are no evidences of dead washed upon shore because the predators consumed which leaves no evidence of otters on the shore.
Second, the reading posits that the evidence of decline in seals and sea lions makes pollution more likely as the cause because not only affects one species it does the same to all. However, the professor contends that orca's may have predated on otters. She states that decline in whales population is caused by human hunting. As the primary fed of orca's declined they predated on smaller creatures like otters, seals and sea lions which caused their respective populations eventually decline.
Third, the reading avers that the uneven concentrations of pollutants caused uneven decline patterns around Alaskan locations. The professor opposes this point by explaining that the Orca predation theory can explain the uneven trends around Alaska. Orca's which are large in size can't fit in the rocky and shallow locations of some of the Alaska beaches. So, in the shallow locations the decline will be less because predeators were absent in those locations.
Grammar and spelling errors:
Line 2, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
The reading states that among environmen...
^^^^^
Line 2, column 141, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'otters'' or 'otter's'?
Suggestion: otters'; otter's
...re likely the reason for decline of sea otters population and provides three reasons o...
^^^^^^
Line 4, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...efutes each of the authors reasons. First, the reading claims that the pollu...
^^^^^
Line 6, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...no evidence of otters on the shore. Second, the reading posits that the evid...
^^^^^
Line 8, column 1, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...ive populations eventually decline. Third, the reading avers that the uneven...
^^^
Line 8, column 270, Rule ID: ADJECTIVE_IN_ATTRIBUTE[1]
Message: A more concise phrase may lose no meaning and sound more powerful.
Suggestion: large
...n trends around Alaska. Orcas which are large in size cant fit in the rocky and shallow locat...
^^^^^^^^^^^^^
Line 8, column 284, Rule ID: CANT[1]
Message: Did you mean 'can't' or 'cannot'?
Suggestion: can't; cannot
...d Alaska. Orcas which are large in size cant fit in the rocky and shallow locations ...
^^^^
Line 8, column 331, Rule ID: SOME_OF_THE[1]
Message: Simply use 'some'.
Suggestion: some
...t in the rocky and shallow locations of some of the Alaska beaches. So, in the shallow loca...
^^^^^^^^^^^
Transition Words or Phrases used:
but, first, however, if, may, second, so, then, third
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 9.0 10.4613686534 86% => OK
Auxiliary verbs: 4.0 5.04856512141 79% => OK
Conjunction : 7.0 7.30242825607 96% => OK
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 17.0 22.412803532 76% => OK
Preposition: 39.0 30.3222958057 129% => OK
Nominalization: 14.0 5.01324503311 279% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1568.0 1373.03311258 114% => OK
No of words: 296.0 270.72406181 109% => OK
Chars per words: 5.2972972973 5.08290768461 104% => OK
Fourth root words length: 4.14784890444 4.04702891845 102% => OK
Word Length SD: 2.55115665771 2.5805825403 99% => OK
Unique words: 157.0 145.348785872 108% => OK
Unique words percentage: 0.530405405405 0.540411800872 98% => OK
syllable_count: 490.5 419.366225166 117% => OK
avg_syllables_per_word: 1.7 1.55342163355 109% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 3.25607064018 31% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 14.0 13.0662251656 107% => OK
Sentence length: 21.0 21.2450331126 99% => OK
Sentence length SD: 37.4261176949 49.2860985944 76% => OK
Chars per sentence: 112.0 110.228320801 102% => OK
Words per sentence: 21.1428571429 21.698381199 97% => OK
Discourse Markers: 3.78571428571 7.06452816374 54% => More transition words/phrases wanted.
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 8.0 4.19205298013 191% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 8.0 4.27373068433 187% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.16278046908 0.272083759551 60% => OK
Sentence topic coherence: 0.0598375689859 0.0996497079465 60% => OK
Sentence topic coherence SD: 0.0323474668699 0.0662205650399 49% => Sentences are similar to each other.
Paragraph topic coherence: 0.104435928843 0.162205337803 64% => OK
Paragraph topic coherence SD: 0.0246963456761 0.0443174109184 56% => OK
Essay readability:
automated_readability_index: 14.1 13.3589403974 106% => OK
flesch_reading_ease: 41.7 53.8541721854 77% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 12.7 11.0289183223 115% => OK
coleman_liau_index: 13.46 12.2367328918 110% => OK
dale_chall_readability_score: 8.73 8.42419426049 104% => OK
difficult_words: 76.0 63.6247240618 119% => OK
linsear_write_formula: 11.0 10.7273730684 103% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 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.