1. MARINE BIOLOGY MID TERM REVIEW

2. What is ecology?
The study of the interactions among organisms, and with the surrounding environment

3. Name 3 major human impacts on the environment :
(Over)population
Pollution
Habitat Destruction
Resource Depletion

4. Name 3 things humans can do to preserve marine life and their environment:
Regulate pollutants and fisheries
Create artificial reefs
Don’t buy shells, coral, etc.
Conserve resources

5. What are plankton?
Organisms that float freely with the currents for all or part of their lives.
Give an example: Crab larvae, diatoms, copepods

6. What are nekton?
Organisms that can swim independently of currents
Give an example: sharks, adult crab, seahorses, adult fish, reptiles, mammals

7. What are benthos (benthic organisms)?
Bottom-dwelling organisms
Give an example: clams, crabs, urchins, barnacles

8. 7. What is the difference between zooplankton and phytoplankton?
Zooplankton are animal-like
Phytoplankton are plant-like
(can carryout photosynthesis)
Give 2 examples of each:
Zoo – copepods, jellyfish, fish larvae
Phyto- diatoms, dinoflagellates, blue-green algae (cyanobacteria)

9. What is the difference between meroplankton and holoplankton?
Mero – spend part of their lives as plankton (usu. Juveniles)
Holo – spend WHOLE life as plankton
Give 2 examples of each:
Mero – crab larvae, lobster larvae
Holo – jellyfish, arrow worm, diatoms

10. Draw the benthic zones.
Sublittoral – subtidal (always covered) benthic orgs
Littoral – Intertidal (covered and uncovered daily)
Supralittoral – Spray zone, above highest high tide

11. Photosynthesis occurs in the photic zone but not in the aphotic zone.
What is the difference between the photic and aphotic zones?
Photosynthesis occurs in the photic zone but not in the aphotic zone.

12. What is detritus?
The dead portion of POM (Particulate Organic Matter)

13. What is the difference between a food chain and a food web?
A food chain consists of only one organism at each trophic level while a food web is an interrelated system of many food chains.

14. What happens to the amount of energy as you move up a food pyramid?
Some energy (10%) is transferred but most energy (90%) is lost after entering each level.

15. What type of organisms occupy the lowest level in every food chain or web?
Producers

16. Compare and contrast the following: population, community, ecosystem
Compare: They are all ecological levels containing living organisms
Contrast: Population consists of members of a single species, community consists of many species, ecosystem consists of a community + abiotic factors

17. What is carrying capacity?
The population an ecosystem can support

18. What is biodiversity?
The number and variety of species living in an area

19. What is symbiosis? (Also describe parasitism, mutualism, commensalism)
Any relationship between organisms where at least one member benefits
Parasitism: Parasite benefits, host is harmed
Mutualism: Both members benefit
Commensalism: One benefits, one is neither helped nor harmed

20. Briefly describe how carbon cycles through the environment (include the ocean!).
Carbon begins in the atmosphere as CO2 and dissolves in the ocean. During photosynthesis carbon is converted to glucose which consumers eat and then exhale carbon dioxide into the atmosphere.

21. 20. Briefly describe how nitrogen cycles through the environment (include the role of bacteria!).
Bacteria convert atmospheric N2 into one of the usable forms of nitrogen during nitrogen fixation. Producers absorb these usable forms and consumers ingest nitrogen by eating producers. Denitrification is then carried out by bacteria returning nitrogen to the atmosphere.

22. Briefly describe how phosphorus cycles through the environment (include how it is returned to land!)
Most phosphate enters rivers by weathering of rocks. Some phosphate enters waterways by human pollution (fertilizers and detergents). Phosphorus is deposited in bio sediments and then eventually returned to the Earth by geological uplift.

23. 22. Briefly describe the water cycle.
Water evaporates from oceans, lakes and streams and also from the leaves of plants and trees (transpiration). It then condenses in the clouds, precipitates back to Earth and returns to the waterways and aquifers via infiltration and surface run-off.

24. 23. Why is life on this planet so dependent on the cycling of nutrients such as carbon and nitrogen?
If these vital elements of life were not recycled through the environment, we would surely deplete these resources.

25. How do humans affect the carbon cycle?
We impact the carbon cycle by burning fossil fuels, which causes global warming and ocean acidification.

26. 25. How do humans affect the nitrogen cycle?
We impact the nitrogen cycle by allowing fertilizers and sewage to enter waterways causing artificial eutrophication. We also burn fossil fuels which puts additional nitrogen into the atmosphere.

27. 26. How do humans affect the phosphorus cycle?
We impact the phosphorus cycle by allowing fertilizers and detergents to enter waterways causing artificial eutrophication.

28. 27. What is a watershed?
The land area that drains to a common body of water such as a stream, lake, river or ocean

29. 28. What is a ridge line?
The boundary along a topographic ridge separating two adjacent drainage basins

30. 29. What is an aquatic buffer?
A natural boundary between local waterways and existing development. They protect water quality by filtering pollutants, sediment and nutrients from runoff.

31. 30. What is the difference between and open and closed watershed?
Open drains to the ocean eventually. Water only leaves a closed watershed via evaporation or seepage.

32. 31. What is an impervious surface?
A surface that does not allow water to infiltrate.
Ex: An asphalt parking lot, a building

33. 32. What can you do to protect your watershed?
Do not use lawn fertilizers or chemicals
Capture rainwater
Use water wisely and conserve
Dispose of pet waste properly

34. 33. What is salinity?
Concentration of minerals (especially NaCl)

35. 34. What 2 substances are found in the greatest concentration in seawater?
Sodium and chlorine (chloride)

36. 35. What is the average salinity of seawater (expressed as ppt)?
35 ppt (parts per THOUSAND, not hundred)
If expressed as parts per hundred, you use %, so you could also say 3.5%

37. 36. What is an estuary?
The place where freshwater from land and saltwater from the ocean combine and mix

38. 37. What is the average salinity of an estuary (expressed as ppt)?
17 ppt (parts per THOUSAND, not hundred)
If expressed as parts per hundred, you use %, so you could also say 1.7%

39. 38. Contrast stenohaline and euryhaline organisms:
Stenohaline orgs cannot tolerate changes in salinity while euryhaline orgs CAN tolerate a wide range of salinity. (Great white sharks can’t tolerate the salinity of an estuarine environment….…yet  )

40. 39. What does being sessile entail?
Sessile orgs remain attached to the substrate or another organism for life.

41. 40. What is the difference between epifauna and infauna?
Epifauna are benthos organisms that live on the surface of the ocean sediment or substrate. INfauna are benthos orgs that live IN the ocean sediment or substrate (burrowed).

42. 41. Describe the different types of estuaries and how they are/were formed:
Coastal plain/flooded river valley – formed when glaciers melted (Chesapeake and Delaware Bay)
Bar-built – formed due to presence of barrier islands (Outer Banks, NC, Island Beach NJ, LBI)
Fjord – formed when past glaciers receded causing a u shaped valleys with steep walls (Canadian coast)
Tectonic – formed when Earth’s crust shifted (San Fran Bay – N. American Plate and Pacific Plate-transform boundary)

43. 42. Why are estuaries important to humans?
Estuaries are a source of commercially important species (oysters, crabs, clams), provide a storm buffer, provide areas for recreation

44. 43. What is turbidity?
Degree of water clarity. Increased turbidity = less clarity, therefore less infiltration of light and less photosynthesis

45. 44. Why are estuaries important to wildlife?
Estuaries provide a habitat for sea birds, are a source of food and resting place for migratory birds, provide safe spawning ground for many anadromous fish, filter pollutants, and act as a sponge and/or buffer during storms.

46. 45. What happens to salinity as you move upstream?
It decreases as you move upstream or away from the higher salinity of seawater.

47. 46. How does the tidal flow and salinity in the upper and lower salt marsh differ?
Upper marsh – sometimes flooded at high tide. Lower salinity, less tidal flow
Lower marsh – always flooded at high tide. Exposed at low tide (mud flat), higher salinity, more tidal flow