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 reading claims that the decline of sea-otters is mainly due to environmental pollution rather than predation. However, the professor disagrees with the arguments that support the pollution theory. He is of the opinion that attack by predators is the primary reason for the decline.
First, the reading mentions that an increased level of chemicals in the ocean water causes infections to this sea mammal. This argument is challenged by the professor by saying that no one can find any dead sea otters on an Alaskan beach due to infections. Furthermore, she believes that dead sea otters better fits with the predation hypothesis as the dead animal is immediately visible on the shores that are washed by the tides.
Next, the reading posits that not only the sea otters, but other sea mammals like sea lions, seals are declining from the coasts that strongly support the pollution hypothesis. The reading elaborates this by mentioning about the decline of whales perpetuates the decrease. On the contrary, the lecturer postulated that the reduction in the number of whales has a direct relation with the decline of sea mammals including sea otters. Otter's prey is whales. While the decline of whales due to human hunters leads to a change in the dietary pattern of the otters to seals and sea lions pave paths for their decline.
Last, the author of the reading shows an uneven pattern of decline that highly suggests the pollution theory. One flaw of this argument is due to the size of sea otters, they cannot locate in shallow or rocky places. So its precisely showing the declines in these areas that challenge the pollution hypothesis.
'
Transition Words or Phrases used:
but, first, furthermore, however, so, while, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 9.0 10.4613686534 86% => OK
Auxiliary verbs: 2.0 5.04856512141 40% => OK
Conjunction : 3.0 7.30242825607 41% => More conjunction wanted.
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 22.0 22.412803532 98% => OK
Preposition: 38.0 30.3222958057 125% => OK
Nominalization: 11.0 5.01324503311 219% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1394.0 1373.03311258 102% => OK
No of words: 276.0 270.72406181 102% => OK
Chars per words: 5.05072463768 5.08290768461 99% => OK
Fourth root words length: 4.07593519647 4.04702891845 101% => OK
Word Length SD: 2.57023786123 2.5805825403 100% => OK
Unique words: 145.0 145.348785872 100% => OK
Unique words percentage: 0.525362318841 0.540411800872 97% => OK
syllable_count: 422.1 419.366225166 101% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 7.0 8.23620309051 85% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 14.0 13.0662251656 107% => OK
Sentence length: 19.0 21.2450331126 89% => OK
Sentence length SD: 40.2215801555 49.2860985944 82% => OK
Chars per sentence: 99.5714285714 110.228320801 90% => OK
Words per sentence: 19.7142857143 21.698381199 91% => OK
Discourse Markers: 4.28571428571 7.06452816374 61% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => 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: 0.267893058621 0.272083759551 98% => OK
Sentence topic coherence: 0.0936531253821 0.0996497079465 94% => OK
Sentence topic coherence SD: 0.0739045238182 0.0662205650399 112% => OK
Paragraph topic coherence: 0.155654932112 0.162205337803 96% => OK
Paragraph topic coherence SD: 0.0838742783692 0.0443174109184 189% => OK
Essay readability:
automated_readability_index: 12.2 13.3589403974 91% => Automated_readability_index is low.
flesch_reading_ease: 60.65 53.8541721854 113% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.5 11.0289183223 86% => OK
coleman_liau_index: 12.01 12.2367328918 98% => OK
dale_chall_readability_score: 8.7 8.42419426049 103% => OK
difficult_words: 72.0 63.6247240618 113% => OK
linsear_write_formula: 7.5 10.7273730684 70% => OK
gunning_fog: 9.6 10.498013245 91% => OK
text_standard: 10.0 11.2008830022 89% => OK
What are above readability scores?
---------------------
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
---------------------
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.