What threats do phytoplankton face

Phytoplankton’s can be exposed to many nutrients which causes HABS (harmful algal blooms) which can make highly toxic compounds that then are a threat to other animals.

the glands which are associated with each description is given below:

pancreas - is an endocrine and exocrine gland that secretes juices with enzymes for digestion. salivary glands- with protection and digestion in the mouth. liver- secretes bile for digestion.   lachrymal glands - secrete tears to moisten eyes and protect them from particles and infection.   sweat gland -regulates water, salt, and temperature. oil glands - to form a protective barrier on the skin.   goblet cells - secrete mucus for protection.

It explains why rocks appear in layers