My textbook question is:

Please look at page 38, Figure 2.6: "How do historians know Cartier traveled these particular routes? Where might they have found supporting historical evidence.

The picture is just a map with the guys travels. (arrows and lines ect)

Please help!

Probably Cartier and/or men with him kept journals and wrote letters detailing their travels. Historians may have supported these written documents with verbal reports from Natives/Aboriginals and even trash that Cartier and his men left behind.

Explain what would happen to the animals and plants in a saltwater ecosystem if it were flooded by fresh water?

i've tried but can't get it right
pleaseeeee help!