Marine Ecology Overview October 24 2018 ECOLOGY From

Marine Ecology Overview October 24, 2018

ECOLOGY From greek ‘oikos’ meaning ‘house’. -The study of organisms ‘at home’.

Ecology is the study of the inter-relationships between the physical and biological aspects of the environment. biotic abiotic It is the study of how organisms adapt to and alter their environment.

What’s Life? üCapture, Store, and Transmit Energy üCapable of Reproduction üAdapt to their Environment üChange through time

There are two major marine provinces: the benthic (bottom) the pelagic (water column)

Define areas in the Ocean by Depth Epipelagic – (epi= top) from the surface to 200 m (660 ft). Mesopelagic – (meso= middle) From to 200 – 1000 m. Bathypelagic – (bathos= depth) From 1000 – 2000 m. Abyssopelagic – (a= without, byssus= bottom) – From 2000 -6000 m to below…all the deepest part of the oceans.

Another way to classify the ocean – light! The photic zone is the depth where light is sufficient for photosynthesis. The dysphotic zone is where illumination is too weak for photosynthesis. The aphotic zone receives no light from the surface because it is all absorbed by New “zone” called the Rariphotic zone, the water above. Between 100 m and 300 m

The area of the ocean water column known as the “twilight zone” is: A. B. C. D. Aphotic Rariphotic Dysphotic Euphotic 25% Aphotic 25% Rariphotic Dysphotic 25% Euphotic

How many species live in the ocean? Over 250, 000! But………. . The Census of Marine Life recently reported…. 5, 000 possible new species were identified. And there are likely more than 750, 000 species yet to be discovered of the 1 million or so thought to exist. Vampire Squid Christmas Tree Worm

Oceanic Life Is Classified by Evolutionary Heritage • Taxonomy – biological classification • Linnaeus – classification system – Kingdoms – Hierarchy • Modern domain classification – Archaea, Bacteria, Eukarya

• In 1735 Linnaeus developed the taxonomic classification used in zoology. • The categories are from largest to smallest: – Kingdom – Phylum – Class – Order – Family – Genus – Species • The name of a species consists of the genus name combined with a trivial name. • The genus name begins with a capital. • The trivial (species) name begins with a lowercase letter.

More inclusive Less inclusive Kingdom Phylum (in plants Division is used) Class Order Family Genus Species

Classification of Organisms Protista: foraminifera, diatom, seaweed -planktonic or benthic -internal membranes -planktonic, benthic, eat or photosynthesize

Plantae: - multi-cell plants -primary producers in intertidal -benthic

Prokaryote Eukaryote

Prokaryote Eukaryote - no nucleus - no membrane bound organelles - usually DNA in a single circular molecule

"I hadn't been trained as a microbiologist, so I didn't have this bias [about impossibility of bacterial classification]. (Woese)

Carl Woese §Bacteria §Archaea §Eukaryotes Make proteins! Based on differences in 16 S r. RNA genes A 16 -S r. RNA subunit is a small component of a ribosome. Assumed to be about the most conserved of the molecular components.

Unusual in cell membrane and flagella structure… DNA transcription similar to eukaryotes

1977, Carl Woese proposed that Archaea are different from bacteria and constitute a new super-kingdom Archaebacteria. 1990 Woese adopted the term 'domain' for the three new branches of life and shortened the name Archaebacteria to Archaea. "Wolfe recalls: 'One Nobel Prize winner, Salvador Luria, called me and said, 'Ralph, you're going to ruin your career. You've got to disassociate yourself from this nonsense!'" The hostility, Woese said, was shocking. Others soon followed, crossing boundaries of common courtesy by making fun of Woese. He was called a crank and a crackpot, being neither a microbiologist nor an evolutionist (Woese was a physicist). "Many leading biologists thought Woese was "crazy" and that his RNA tools couldn't possibly answer the question he was asking.

They differ from Bacteria: 1. in the form and structure of their *ribosomes 2. the type and linkage of their lipids 3. structure of the cell covering 4. different type of RNA polymerase (Margulis and Schwartz 1998). *Ribosomes make proteins…. RNA polymerase is an enzyme in ribosomes that helps facilitate the making of proteins….

Archaea • Life cannot be classified by the two-domain system of bacteria and eukaryote. • Some bacteria are as different genetically from other bacteria as they are from humans. • This necessitates a third domain, the Archaea.

The Three-Domain System

Table 10. 1

Archaea- most are anaerobes incapable of living in air. ~3. 5 billion years ago Most thrive in extreme conditions hot springs, freezing water…. (although they have Been found everywhere). “earliest terrestrial life-forms” http: //www. daviddarling. info/images/archaea. jpg

Bacteria - usually unicellular organisms. ~3 billion years ago All bacteria are prokaryotes, which means that they don't have a nucleus or other membrane-bound organelles. They are normally a few micrometers long and they have many shapes which include spheres, rods, and spirals.