Passage 1
Invasive Species: A Nuisance to Mankind
Invasive species are organisms that are not native to a particular region. They can move to habituate another place by swimming or using the hull or a ballast tank of a ship. These invasive species either die because they cannot adapt to the new surroundings, or survive with little or no impact on the native species. In some cases, they become dominant and eat or fight with the native species for food and space.
The zebra mussel, an invasive species, was accidentally introduced by a cargo ship into Lake St. Clair. The mussels multiplied and spread rapidly throughout the Great Lakes and the Mississippi River. Mussels endangered the diversity and the abundance of the native species. The government spends millions of dollars every year to control their numbers. The smothering seaweed, another invasive algae, endangers the coral reefs of the Hawaii. The algae multiply faster than the native algae and coral. The tourist island is now dominated by algae rather than corals.
The invasive species have an adverse impact on the environment and the flora and fauna of that region. Governments need to control these species by detecting their invasion and taking steps to control and manage them at an early stage.
Passage 2
Invasive Species Used for Aquafarming
There are billions of marine species, and each of them flourishes in the habitat in which it originates or evolves. However, certain aquatic species invade the territories of the species native to a particular region. This has an impact on the native species, and on the ecology, economy, and the environment. Invasive species are considered a nuisance. However, these species also offer some benefits.
With the increase in global population, the demand for food has grown. The Chinese Mystery Snail, an invasive species, was brought from Asia to the San Francisco Bay region over 40 years ago for culinary use. Most seafood, including native and invasive species, is healthy and can feed approximately one billion people every day. Invasive species such as seaweed are rich in nutrients and fiber, thus serving as healthy food for humans. Because of a decrease in native species' fisheries, the Asian oysters (Crassostrea gigas), an invasive species, were introduced in most parts of the world to meet the growing demand for food. These oysters filter water pollutants better than native oysters. The European brown trout, another invasive species, has been introduced to new locations for recreational fisheries, for food, and to promote aquaculture or aquafarming. The annual U.S. trout industry was almost $80m in 2001. Aquafarming using invasive species has grown rapidly in the past few years, contributing to about one-third of the total demand for fish.
In "Invasive Species: A Nuisance to Mankind," how does paragraph 2 refine the author's ideas?
A.
It lists the causes that explain how people deliberately introduce invasive species in a particular habitat for their selfish gains.
B.
It gives examples of how invasive species, such as zebra mussels and seaweed, endanger the survival of native species.
C.
It presents the problem of rapidly multiplying species, and it also suggests methods to control their populations.
D.
It presents information in a logical order to show how the smothering seaweed dominates the coral reefs.