Health

Yes. Lamprey and hagfish are both jawless fishes. They are the only living members of the taxonomical class Agnatha (Greek for “no jaws”). 
No, salmon are not endangered worldwide. For example, most populations in Alaska are healthy. Some populations in the Pacific Northwest are much healthier than others.
Experimentally, it was found that this may be possible.
This is a common problem. The bird sees the reflection and thinks it is another bird encroaching on his territory. One solution is to put a silhouette of a hawk in the window. That scares them off.
Signs of infection in wildlife, like in humans, can range from no symptoms to severe symptoms of neurologic illness.
The scientific community is certain that the Earth's climate is changing because of the trends that we see in the instrumented climate record and the changes that have been observed in physical and biological systems.  The instrumental record
The earth is estimated to hold about 1,460,000,000 cubic kilometers of water. The breakdown of where all that water resides is estimated as follows:
Since 1950, the USGS has collected and analyzed water-use data for the United States and its Territories. That data is revised every 5 years.