Pelagic zoneThe pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word pelagic is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change.
Congener (chemistry)In chemistry, congeners are chemical substances "related to each other by origin, structure, or function". Any significant quantity of a polyhalogenated compound is by default a blend of multiple molecule types because each molecule forms independently, and chlorine and bromine do not strongly select which site(s) they bond to. Polychlorinated biphenyls (PCBs) are a family of 209 congeners. Polybrominated biphenyls and polychlorinated diphenyl ethers are also families of 209 congeners.
FaunaFauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding term for plants is flora, and for fungi, it is funga. Flora, fauna, funga and other forms of life are collectively referred to as biota. Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess Shale fauna". Paleontologists sometimes refer to a sequence of faunal stages, which is a series of rocks all containing similar fossils.
ChlordeconeChlordecone, better known in the United States under the brand name Kepone, is an organochlorine compound and a colourless solid. It is an obsolete insecticide, now prohibited in the western world, but only after many thousands of tonnes had been produced and used. Chlordecone is a known persistent organic pollutant (POP) that was banned globally by the Stockholm Convention on Persistent Organic Pollutants in 2009. Chlordecone is made by dimerizing hexachlorocyclopentadiene and hydrolyzing to a ketone.
BivalviaBivalvia (baɪˈvælviə), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. The class includes the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater.
