An estuary is an area where a freshwater river or stream meets the ocean. In estuaries, The salty ocean mixes with a fresh water river, resulting in brackish water. Brackish water is someone salty, but not as salty as the ocean. An estuary may also be called a bay, lagoon, sound, or slough.
Double layered nuclear, the outer nuclear membrane is continuous with the membrane of the rough endoplasmic reticulum (ER), it also continues with the inner nuclear membranes since the two layers are fused together at a numerous tiny holes called nuclear pores that perforate the nuclear enevelope