Lead.
"Due to insufficient water treatment, lead leached from water pipes into the drinking water, exposing over 100,000 residents to elevated lead levels."
Answer: the capillaries.
<span>The blood capillaries are blood vessels with very small caliber. They form the blood distribution and collection network in cells. They are the communication between branches
originating from the arteries and with the smaller
veins. It is on the walls of the capillaries that occurs <span>the exchange of water, oxygen, CO2,
other nutrients and chemical residues.</span></span>
Well as a population grows, resources become scarcer to accommodate for the growing population. So either the Minnows leave to different areas or they fight for the resources. I have finished BIO a few months ago(maybe more idk) so if I’m incorrect I do apologize, but good luck anyway. :)
Its IV. forests are habitat for two-thirds of terrestrials species....................