1. MARINE ENVIRONMENTS

2. Marine Biologists categorize communities according to WHERE and HOW organisms live.
Benthic (or benthos) – organisms that live on or buried in the bottom
Sessile – attached organisms (do not swim)
Pelagic – organisms that live higher in the water column (away from the bottom)

4. Pelagic thresher shark

5. Pelagic organisms are further divided according to how well they swim.
Plankton – organisms that swim weakly
Drift in water
Phytoplankton (example: algae) – most important primary producers in marine ecosystem
Zooplankton – small heterotrophic organisms
Nekton – animals that can swim well enough to oppose currents
Mostly vertebrates

9. Classification of the Benthic Environment
Benthic environment on continental shelf is divided into 2 regions:
Intertidal (or littoral) zone – boundary between land and sea;
shallowest part of the continental shelf
At the mercy of the tides
Subtidal (or sublittoral) zone – continental shelf beyond the intertidal zone

11. Abyssal Zone – deepest environment of sea floor
The Benthic environment beyond the continental shelf is called “the deep sea floor”.
Abyssal Zone – deepest environment of sea floor
< 4,000 meters deep
Organisms in the abyssal zone are adapted to extremely cold temperatures and high pressures.

12. Classification of the Pelagic Environment – by depth
Neritic Zone – pelagic environment that lies over the continental shelf
Less than 300 meters deep
Oceanic Zone – waters beyond the shelf

13. Classification of the Pelagic Environment – by amount of light
Photic zone - depths which receive sufficient light to support photosynthesis
meters deep
Phytoplankton thrive in this area – producing food for the rest of the ecosystem
Aphotic zone - depths that receive insufficient light to support photosynthesis

14. Zonation in a Marine Environment
The marine environment is categorized by distance from shore, amount of light, and depth of water. The photic zone (depths which receive sufficient light to support photosynthesis) consists of the intertidal zone (exposed to air when the tide changes), the neritic zone (water less than 300 meters deep) and the oceanic zone. Water depths that receive insufficient light to support photosynthesis are designated as aphotic. The third ocean environment consists of the bottom or benthic zone, which spans across all ocean depths. A variety of organisms that feed on detritus (decomposing organic matter) live in the benthic zone. The deepest benthic area is referred to as the abyssal zone. Organisms living in the abyssal zone (usually considered to be at depths greater than 12,000 ft or 4,000 m) are adapted to extremely cold temperatures and high pressures.
References:
Campbell, N.E., & Reece, J.B. (2002). Biology,(6th ed.). San Francisco: Benjamin Cummings.
Raven, P.H., & Johnson, G.B. (2002). Biology, (6th ed.). McGraw-Hill.
Image Reference:
Baylor College of Medicine, Center For Educational Outreach. (2004). Martha Young, Senior Graphic Designer.

15. An Introduction to the Drifters
Plankton
An Introduction to the Drifters

16. What are plankton? Planktos – Greek meaning “to wander”
Weakly swimming or drifting organisms
Microscopic or macroscopic in size
Plant (phytoplankton) or animal (zooplankton)

17. Why are plankton important?
Food source (basis of the food web)
Producer of oxygen (photosynthesis)
Cause of toxic “blooms” (resulting in fish kills and shellfish poisoning)
Means for dispersal of organisms by transport in currents
Major players in the global carbon cycle

18. How are plankton studied?
Collected with sampling bottles
Special nets
Microscopes
Cultured in labs
Photo by: Lisa Wu
Students aboard the R/V Slover in the southern Chesapeake Bay

19. Collection Methods
Fish and invertebrate larvae (net plankton) are collected during plankton tows
Depth, distance towed, and the volume of water sampled must be calculated
Mesh sizes of nets vary depending upon what is being researched
This plankton net is being deployed to collect near-surface plankton in Maug caldera. The net is about 2 m (6.5 ft) long and has a mesh size of 236 microns (0.25 mm or 0.01 in).
The large aluminum frame of the neuston net is 1 meter high and 3 meters long. Here the net is being deployed off the starboard side of the R/V Seward Johnson

20. ship or carried by divers to collect drifting organisms
Collecting Plankton
Bongo nets are towed
over the side of the
ship or carried by divers to
collect drifting organisms
Image ID: fish1014, NOAA's Fisheries Collection Photo Date: 1987 Photographer: Captain Robert A. Pawlowski, NOAA Corps
Image ID: nur05536, Voyage To Inner Space - Exploring the Seas With NOAA Collect Photographer: J. Morin Credit: OAR/National Undersea Research Program (NURP)
Deploying Bongo nets for sampling plankton

21. Can plankton be studied from space?
Satellites equipped with color scanners measure the concentration of chlorophyll in the ocean
Red = high concentration of chlorophyll
Chlorophyll is the major pigment for photosynthesis in phytoplankton
Data provides information concerning biomass, productivity, and changes in plant populations
Satellite Image of the Gulf of Maine

22. Phytoplankton blooms observed in the Atlantic Ocean off Africa
Image ID: spac0361, NOAA In Space Collection May 2

23. Do organisms spend their entire lives as plankton?
Holoplankton spend their entire life cycle as plankton. Examples include: dinoflagellates, diatoms and krill
Meroplankton spend only a part of their life cycle drifting. As they mature they become nekton (free swimmers) or benthic (crawlers)
Examples include: fish and crab larvae.
Charleston Bump Expedition. Zooplankton, crab larva. Image ID: expl0172, Voyage To Inner Space - Exploring the Seas With NOAA Collect Location: Southeast of Charleston, South Carolina Photo Date: 2003 August 7 Photographer: Jerry Mclelland Credit: Charleston Bump Expedition NOAA Office of Ocean Exploration; Dr. George Sedberry, South Carolina DNR, Principal Investigator

24. Plankton Observation Worksheet
sketch
Specimen # ___________
Characteristics: Description
Body shape/Tail/flagella/appendages/eyes
Transparency/gills/other features
______________________
Circle one from each category:
Phytoplankton or Zooplankton
Holoplankton or Meroplankton

25. Examples of Plankton Specimen #1

26. Specimen #2

27. Specimen #3

28. Specimen #4

29. Specimen #5

30. Specimen #6

31. Specimen # 7

32. Specimen #8

33. Specimen #9

34. Specimen #10

35. Intertidal Communities
Most studied and best understood marine environment
Intertidal – part of the sea floor that lies between the highest and the lowest tides

36. Unique due to regular exposure to air
The size and species composition of the intertidal will vary with degree of exposure

37. Organisms must be adept at surviving in these arid conditions
Problems to be dealt with because of exposure to air:
Desiccation (drying out)
Mobile organisms move in & out with tide
Protective shells and/or mucus
Store water efficiently
Temperature (very warm temp)
Organisms have a wide temperature range
Light color of shell reflects light

38. Salinity (concentration of salt)
When it rains or snow melts, exposed plants and animals have to endure fresh water
Must have a wide range of salinity tolerance
Wave Action (mechanical effects that smash and tear away objects from substrates or to alter seafloor)
Adaptations to maintain position include: becoming fixed to rocks (sessile), increasing thickness of shell, enlarging muscular foot

39. Vertical Zonation of Intertidal
Zonation is a vertical banding of the organisms living on the rocky coastline

40. The Supralittoral Zone “The Splash Zone”
Upper part of intertidal zone
Size of this zone depends on slope, splash, climate, and amount of shade
Only covered briefly by water during the highest tides
Dissolved nutrients and oxygen are limited

41. Black Lichen Black, tar-like blotches on rocks
Symbiotic relationship of fungi and algae
Fungi soaks up water like a sponge, storing it for long dry periods

42. Cyanobacteria Blue-green algae
Protected from desiccation by a jelly-like coating

43. Periwinkles Snail-like mollusks Abundant in intertidal
Avoid desiccation by:
clustering in moist, shady crevices.
Sealing opening of shell
Can breathe air
Tolerate extreme temps.

44. Limpet Soft-bodied invertebrate protected by a hard, cone-like shell
Cling tightly to rocks using muscular foot

45. Upper Tidal Zone Middle Tidal Zone Lower Tidal Zone
Intertidal communities are separated by a process called Zoneation. Using zoneation we can identify four different zones; the upper, middle, lower, and sub-tidal zones.
The upper inter tidal zone contains creatures like periwinkles, barnacles and limpets.
The middle intertidal zone supports more species of barnacles including gooseneck barnacles, as well as mussels and other sea animals.
The lower intertidal zone contains sea grasses, algae, and many of the sea animals that can be found in the intertidal community.

46. The middle intertidal zone contains mussel colonies like the one seen here. Mussels are larger than Gooseneck barnacles, but similar in appearance. Mussels are also able to clamp down during periods of low tide, but because they are in a lower tidal zone, they are not exposed to
desiccation as long as their counterparts in the upper intertidal zone. Mussels use strong hairs called bysal threads to attach themselves to rocks. Once there, they feed on microscopic plants filtered out of the sea water. They can grow anywhere from 3 inches up top 8 inches in length! Mussels are very good to eat, and work as a good fish bait as well.

48. Vertical Zonation of the Intertidal
Upper Tidal Zone
Vertical Zonation of the Intertidal
Middle Tidal Zone
Lower Tidal Zone

49. Upper Intertidal Zone
Harsh environment - exposed to rough waves during high tide and the hot sun during low tide
Includes same species as supralittoral (splash) zone

50. Striped Shore Crab Square Body Eyes at corners movie
Eat algae growing on the rocks by scraping with claws
Also prey on dead animals and live limpets & snails

51. Middle Intertidal
Most active intertidal zone because it is fully covered and uncovered each day
Upper boundary is always marked by a band of acorn barnacles

52. Acorn Barnacle Attach firmly to substrate
Valve-like "doors" in shell that open when animal is submerged, and close when it is exposed to air
Feed on plankton by sucking in the water around them, while closing their teeth and opening their mouth. Then they lick all the plankton that are stuck in their teeth.

53. Ochre Sea Star
Tiny suction cups called tube feet cover the underside of their five arms
Vicious predator of mussels
Extend stomach to externally digest food.
Regenerate body parts

54. California Mussel Large colonies on exposed rocks
Formation into dense clusters helps them retain moisture and lessens wave shock.
Feed by filtering plankton
Provide shelter for smaller organisms
Often considered a delicacy, mussels should not be eaten between the dates of May 1 and October 31. During this time mussels may filter and accumulate an extremely toxic plankton. Consuming mussels during this period can cause paralysis and death in humans.

55. Lower Intertidal Zone Dry only during lowest tides
Contains greatest biodiversity of intertidal zones

56. Gooseneck Barnacles Free-swimming larvae Develop and attach to rocks
Long, neck-like stalk
Produce very strong adhesives
Use feathery feet to filter food from passing water
Live up to 20 years

57. Limpet
Gooseneck Barnacles

58. Sunflower Star Major predator
The older they become, the more rays they grow. (up to 24 rays)
When threatened, these stars can drop an arm in hopes of appeasing the predator. The arm will later re-grow.