Red squirrels and gray squirrels have been the native species on an island for many years. a few years ago, black squirrels entered this island. the black squirrel is an invasive species. invasive species aren’t native to the ecosystem. they move into an ecosystem because of natural changes or human intervention. red squirrels and black squirrels have identical food requirements, but gray squirrels have a different diet. what three effects will these events have on the island’s squirrel population? -the food availability of red squirrels may increase. -the red and black squirrels will have to compete for nutrition. -the food availability for gray squirrels will not be affected. -the food availability for red squirrels may decrease. -the food availability for gray squirrels will be affected.

The THREE effects on the island's squirrel will be The red and black squirrels will have to compete for nutrition:

the correct option is option d

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.