Lecture 36 - Marine Environments Flashcards
What are 4 categories of marine animals?
- plankton
- nekton
- benthos
- decomposers
What are plankton?
-weakly swimming, free-floating biota
What are 3 types of plankton?
- Phytoplankton (plant)
- Zooplankton (animal)
- Ultraplankton (photosynthetic bacteria)
Nekton EX
fish, turtles, whales
Benthos EX
bottom dwellers (barnacles, oysters)
What are decomposers?
-breakdown organic compounds (mostly bacteria)
Where is most action?
-Costal waters
2 characteristics of the Coastal Zone
- warm, nutrient-rich shallow water
2. extends from high-tide mark on land to gently sloping/shallow edge of continental shelf
What are Estuaries?
Where rivers enter the ocean
EX: river mouths, inlets, bays, sounds, salt marshes etc.
What are salt marshes
- some of most productive habitats on earth
- serve as fish nurseries
What is SAV?
- submerged aquatic vegetation
- Eelgrass
What is a Mangrove forest?
- found along 70% of gently sloping sand/silty coastlines
- tropical/subtropical regions
What is a kelp forest
- contains certain type of plant that forms forest
- houses resident fish + visitors
What is the effect of sea otters on kelp forests?
- eat the urchins
- otherwise kelp will die
What is Coral bleaching
-corals lose their zooxanthellae when stressed
5 traits of coral reefs
- 1-9 millino species
- 1/2 ocean’s total biodiversity
- high level of producitivty
- 100 million people directly dependent on healthy coral reefs
- threatened due to ocean acidification
What is the deep sea? (3)
- cold, dark immense pressure
- little to eat (not lifeless)
- largest habitat on planet
5 realms of the deep sea from shallow-deep
- Mesopelagic
- Bathypelagic
- Bathyal
- Abyssal
- Hadal
3 characteristics of animals in Mesopelagic Realm
- small size, huge eyes, large jaws/teeth
- bioluminescence + countershading
- Daily (diel) vertical migrations
6 characteristics of bioluminescence
- biologically produced light
- symbiotic bacteria
- predator avoidance
- species recognition
- prey attraction
- mate attraction
What is countershading?
-lights on underside make fish less visible from below
What are lantern fish?
-last unexploited stocks of fish (could change soon)
What is the Deep Scattering Layer
- worldwide phenomena after WWII
- detected by sonar
5 key characteristics of the Bathypelagic Realm
- bigger individuals (lower biomass, abundance)
- high species diversity
- black + red in color
- no vertical migrations to surface
- small/large eyes, bioluminscence
2 opportunists of the Bathypelagic Realm
- Gulper eel
2. Angler fish
2 characteristics of deep-sea floor
- soft bottoms
2. hydrothermal vents + cold seeps
What are Hydrothermal Vents/ Cold seeps
- oases of life
- located at mid-oceanic ridges (underwater mountain ranges)
What are the base of food webs in hydrothermal vents/cold seeps?
-symbiotic chemoautotrophs
Who discovered deep sea hydrothermal vents?
Alvin and RV Atlantis in 1977
Bob Ballard “accidental” celebrity explorer
What is Alvin’s Sipper?
extending want that collects water samples at hydrothermal vents
What is black smoke?
-rich in minerals ion, salt, manganese, sulfer
What is white smoke
more manganese (lower temp)
What is chemosynthetic bacteria?
-in total darkness they use chem. energy to “fix” carbon + produce food
