The sea otter is a small mammal that lives in waters along the western coast of North America from California to Alaska. When some sea otter populations off the Alaskan coast started rapidly declining a few years ago, it caused much concern because sea otters play an important ecological role in the coastal ecosystem. Experts started investigating the cause of the decline and quickly realized that there were two possible explanations: environmental pollution or attacks by predators. Initially, the pollution hypothesis seemed the more likely of the two.
The first reason why pollution seemed the more likely cause was that there were known sources of it along the Alaskan coast, such as oil rigs and other sources of industrial chemical pollution. Water samples from the area revealed increased levels of chemicals that could decrease the otters’ resistance to life-threatening infections and thus could indirectly cause their deaths.
Second, other sea mammals such as seals and sea lions along the Alaskan coast were also declining, indicating that whatever had endangered the otters was affecting other sea mammals as well. This fact again pointed to environmental pollution, since it usually affects the entire ecosystem rather than a single species. Only widely occurring predators, such as the orca (a large predatory whale), could have the same effect, but orcas prefer to hunt much larger prey, such as other whales.
Third, scientists believed that the pollution hypothesis could also explain the uneven pattern of otter decline: at some Alaskan locations the otter populations declined greatly, while at others they remained stable. Some experts explained these observations by suggesting that ocean currents or other environmental factors may have created uneven concentrations of pollutants along the coast.
The passage is about rapid decline in the population of a small mammal called sea otter which plays an impotant role in coastal ecosystem. There are two competing explanations, environmental pollution and predator attacks. The passage supports the pollution theory while the lecture supports the theory of the attack by predators.
Firstly, the passage states that there were known sources of pollution along the Alaskan coast and the water smaples revealed increased level of chemicals in the water. So, pollution fits more better. But the professor refutes this point by saying that if pollution was the case than dead otters should have been found at the sea beaches. In her opinion, the absence of dead otter bodies is a better indicator that the decline in the otter population is due to predation rather than pollution.
Secondly, The passage posits that a likely predator which is a type of whale called orca, prefer hunting other whale and not the otters. But the professor states that the human hunting of the whales might have casued shift in the habit of the whales of hunting other whales. Due to the paucity of whales, they might eat other smaller creatures like otters and even seals and sea lions. This can account for the decline in the population of the other sea mammals too.
Finally, the passage presents uneven pattern of otter decline as the evidence of pollution being the cause. But according to the professor, predation by orca better explains the uneven pattern. The population of otter declined much where the ocra can access the water. Furthermore, the ocra being large animal, it cannot access shallow water or rocky water. The population of otter also declined less in such places where the orcas cannot access. So, the professor posits that the uneven pattern of decline suits better with the theory of predation.
Grammar and spelling errors:
Line 3, column 189, Rule ID: MOST_COMPARATIVE[2]
Message: Use only 'better' (without 'more') when you use the comparative.
Suggestion: better
...micals in the water. So, pollution fits more better. But the professor refutes this point b...
^^^^^^^^^^^
Transition Words or Phrases used:
also, but, finally, first, firstly, furthermore, if, second, secondly, so, while
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 10.0 10.4613686534 96% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 9.0 7.30242825607 123% => OK
Relative clauses : 10.0 12.0772626932 83% => OK
Pronoun: 11.0 22.412803532 49% => OK
Preposition: 36.0 30.3222958057 119% => OK
Nominalization: 17.0 5.01324503311 339% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1548.0 1373.03311258 113% => OK
No of words: 308.0 270.72406181 114% => OK
Chars per words: 5.02597402597 5.08290768461 99% => OK
Fourth root words length: 4.18926351222 4.04702891845 104% => OK
Word Length SD: 2.39851355273 2.5805825403 93% => OK
Unique words: 156.0 145.348785872 107% => OK
Unique words percentage: 0.506493506494 0.540411800872 94% => More unique words wanted or less content wanted.
syllable_count: 485.1 419.366225166 116% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 10.0 8.23620309051 121% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 3.0 1.51434878587 198% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 17.0 13.0662251656 130% => OK
Sentence length: 18.0 21.2450331126 85% => The Avg. Sentence Length is relatively short.
Sentence length SD: 33.37829724 49.2860985944 68% => OK
Chars per sentence: 91.0588235294 110.228320801 83% => OK
Words per sentence: 18.1176470588 21.698381199 83% => OK
Discourse Markers: 4.70588235294 7.06452816374 67% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 7.0 4.33554083885 161% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 7.0 4.27373068433 164% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.231448659575 0.272083759551 85% => OK
Sentence topic coherence: 0.0761319550449 0.0996497079465 76% => OK
Sentence topic coherence SD: 0.0733029451912 0.0662205650399 111% => OK
Paragraph topic coherence: 0.136926859483 0.162205337803 84% => OK
Paragraph topic coherence SD: 0.0302965167857 0.0443174109184 68% => OK
Essay readability:
automated_readability_index: 11.3 13.3589403974 85% => Automated_readability_index is low.
flesch_reading_ease: 53.21 53.8541721854 99% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 10.3 11.0289183223 93% => OK
coleman_liau_index: 11.6 12.2367328918 95% => OK
dale_chall_readability_score: 8.37 8.42419426049 99% => OK
difficult_words: 75.0 63.6247240618 118% => OK
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 9.2 10.498013245 88% => OK
text_standard: 12.0 11.2008830022 107% => 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.