The zebra mussel, a freshwater shellfish native to Eastern Europe, has long been spreading out from its original habitats and has now reached parts of North America. There are reasons to believe that this invasion cannot be stopped and that it poses a serious threat to freshwater fish populations in all of North America.
First, the history of the zebra mussel's spread suggests that the invasion might be unstoppable. It is a prime example of an invasion made possible by human transportation. From the zebra mussel，s original habitats in Eastern Europe, ships helped spread it out along new canals built to connect Europe’s waterways. The mussel can attach itself to a ship’ s bottom or can survive in the water—called "ballast water"—that the ship needs to take on to properly balance its cargo. By the early nineteenth century, the mussel had spread to the whole of Europe. It was later carried to the east coast of North America in the ballast water of ships traveling from Europe. The way ships have spread the zebra mussel inthe past strongly suggests that the species will soon colonize all of North America.
Moreover, once zebra mussels are carried to a new habitat, theycan dominate it. They are a hardy species that does well under a variety of conditions, and they have a high rate of reproduction. Most important, however, zebra mussels often have no predators in their new habitats, and species without natural predators are likely to dominate their habitats.
Finally, zebra mussels are likely to cause a decline in the overall fish population in habitats where they become dominant. The mussels are plankton eaters, which means that they compete for food with many freshwater fish species.
Both the lecture and the text are on the opposite ends about the halt of Zebra mussel's invasion. The former casts doubt on the hypotheses that zebra mussels are unstoppable to spread out. While the latter offers several theories to justify that their legacy is hard to control.
The first point of dispute is revolving around the idea that human transportation in the sea water will accumulate the dominance of zebra mussels. The professor quickly discards the idea by stating that people have enough knowledge now about the water transportation than past. Therefore, they can prevent the carriage of the mussels by emptying the cargo near the coast yard. Since the mussels require deep ocean water to survive, they can't sustain near the sea where the water is scarce. Nonetheless, the article claims that the past history of mussel's survival and invasion in the Europe by the cargo ships indicate that they will be multiplied in North America as well.
Another point of argument is related to the fact that the zebra mussel will be the most dominant species in its' habitat. The instructor again opposes the idea by mentioning that it was happened only in the beginning that there were no predators for the mussels. However, in the present time arctic birds look for the mussels as their food sources and those birds are abundant in North America. Therefore, they will eat a large number of zebra mussels and reduce their dominance. In contrast, the reading believes that zebra mussel will be the powerful species in their habitats because they have no natural predators.
Last but not the least, the final point of debate focuses on the concern that there will be an increased amount of competition between mussel and other sea fishes for food sources. One last time, the professor rebuts the claim and poses that it will surprisingly bring positive benefits to the sea animals. The bottom sea fishes actually feed on the zebra mussels. Therefore, if zebra mussels eat the plankton as foods, then the bottom sea fishes can have healthy diets since planktons are good for them. However, the passage states that it will create more competition among the sea species and reduce other sea fishes.
Grammar and spelling errors:
Line 3, column 433, Rule ID: CANT[1]
Message: Did you mean 'can't' or 'cannot'?
Suggestion: can't; cannot
...equire deep ocean water to survive they cant sustain near the sea where the water is...
^^^^
Line 5, column 415, Rule ID: LARGE_NUMBER_OF[1]
Message: Specify a number, remove phrase, or simply use 'many' or 'numerous'
Suggestion: many; numerous
...n North America Therefore they will eat a large number of zebra mussels and reduce their dominanc...
^^^^^^^^^^^^^^^^^
Transition Words or Phrases used:
actually, but, first, however, if, look, nonetheless, so, then, therefore, well, while, in contrast
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 14.0 10.4613686534 134% => OK
Auxiliary verbs: 10.0 5.04856512141 198% => OK
Conjunction : 8.0 7.30242825607 110% => OK
Relative clauses : 14.0 12.0772626932 116% => OK
Pronoun: 28.0 22.412803532 125% => Less pronouns wanted
Preposition: 45.0 30.3222958057 148% => OK
Nominalization: 7.0 5.01324503311 140% => OK
Performance on vocabulary words:
No of characters: 1803.0 1373.03311258 131% => OK
No of words: 371.0 270.72406181 137% => Less content wanted.
Chars per words: 4.85983827493 5.08290768461 96% => OK
Fourth root words length: 4.38877662729 4.04702891845 108% => OK
Word Length SD: 2.29552451519 2.5805825403 89% => OK
Unique words: 181.0 145.348785872 125% => OK
Unique words percentage: 0.487870619946 0.540411800872 90% => More unique words wanted or less content wanted.
syllable_count: 564.3 419.366225166 135% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 0.0 3.25607064018 0% => OK
Article: 1.0 8.23620309051 12% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 0.0 2.5761589404 0% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 1.0 13.0662251656 8% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 371.0 21.2450331126 1746% => The Avg. Sentence Length is relatively long.
Sentence length SD: 0.0 49.2860985944 0% => The essay contains lots of sentences with the similar length. More sentence varieties wanted.
Chars per sentence: 1803.0 110.228320801 1636% => Less chars_per_sentence wanted.
Words per sentence: 371.0 21.698381199 1710% => Less words per sentence wanted.
Discourse Markers: 99.0 7.06452816374 1401% => Less transition words/phrases wanted.
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 0.0 4.45695364238 0% => More negative sentences wanted.
Sentences with neutral sentiment: 0.0 4.27373068433 0% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.175764169983 0.272083759551 65% => OK
Sentence topic coherence: 0.175764169983 0.0996497079465 176% => OK
Sentence topic coherence SD: 0.0 0.0662205650399 0% => Sentences are similar to each other.
Paragraph topic coherence: 0.11328028827 0.162205337803 70% => OK
Paragraph topic coherence SD: 0.0366835119626 0.0443174109184 83% => OK
Essay readability:
automated_readability_index: 187.0 13.3589403974 1400% => Automated_readability_index is high.
flesch_reading_ease: -296.63 53.8541721854 -551% => Flesch_reading_ease is low.
smog_index: 0.0 5.55761589404 0% => Smog_index is low.
flesch_kincaid_grade: 146.8 11.0289183223 1331% => Flesch kincaid grade is high.
coleman_liau_index: 12.39 12.2367328918 101% => OK
dale_chall_readability_score: 25.36 8.42419426049 301% => Dale chall readability score is high.
difficult_words: 78.0 63.6247240618 123% => OK
linsear_write_formula: 56.0 10.7273730684 522% => Linsear_write_formula is high.
gunning_fog: 150.4 10.498013245 1433% => Gunning_fog is high.
text_standard: 187.0 11.2008830022 1670% => The average readability is very high. Good job!
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.