Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds

1. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds

2. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Formed by glacial scouring, oxbows, filling of craters, uplift blocking a stream, and natural/anthropogenic damming

3. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Formed by glacial scouring, oxbows, filling of craters, uplift blocking a stream, and natural/anthropogenic damming The littoral zone is where rooted plants can live; the limnetic zone is deeper water where rooted plants can't live. profundal

4. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Formed by glacial scouring, oxbows, filling of craters, uplift blocking a stream, and natural/anthropogenic damming The littoral zone is where rooted plants can live; the limnetic zone is deeper water where rooted plants can't live. There is also habitat subdivison by temp; epilimnion, metalimnion (thermocline), and hypolimnion

6. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Formed by glacial scouring, oxbows, filling of craters, uplift blocking a stream, and natural/anthropogenic damming The littoral zone is where rooted plants can live; the limnetic zone is deeper water where rooted plants can't live. There is also habitat subdivison by depth; epilimnion (photic), metalimnion (thermocline), and hypolimnion Shallow lakes (ponds) have a higher ratio of littoral/limnetic; as such, productivity is high - producing more biomass than the decomposers may be able to breakdown.

7. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Formed by glacial scouring, oxbows, filling of craters, uplift blocking a stream, and natural/anthropogenic damming The littoral zone is where rooted plants can live; the limnetic zone is deeper water where rooted plants can't live. There is also habitat subdivison by depth; epilimnion (photic), metalimnion (thermocline), and hypolimnion Shallow lakes (ponds) have a higher ratio of littoral/limnetic; as such, productivity is high - producing more biomass than the decomposers may be able to breakdown. This stimulates decomposition and drives down oxygen concentrations... this excessive productivity distinguishes a eutrophic lake.

9. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Formed by glacial scouring, oxbows, filling of craters, uplift blocking a stream, and natural/anthropogenic damming The littoral zone is where rooted plants can live; the limnetic zone is deeper water where rooted plants can't live. There is also habitat subdivison by depth; epilimnion (photic), metalimnion (thermocline), and hypolimnion Shallow lakes (ponds) have a higher ratio of littoral/limnetic; as such, productivity is high - producing more biomass than the decomposers may be able to breakdown. This stimulates decomposition and drives down oxygen concentrations... this excessive productivity distinguishes a eutrophic lake. These eutrophic conditions can be stimulated by the anthropogenic input of nutrients - stimulating productivity above natural levels. - phosphates often a culprit

11. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Deep lakes have a lower littoral/limnetic ratio; decomposition in the limnetic is limited by the relatively low input of biomass from the littoral zone; oxygen concentrations remain high; water remains clear, and communities remain diverse. These are called oligotrophic systems.

12. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Deep lakes have a lower littoral/limnetic ratio; decomposition in the limnetic is limited by the relatively low input of biomass from the littoral zone; oxygen concentrations remain high; water remains clear, and communities remain diverse. These are called oligotrophic systems. Deep lakes in the temperate zone proceed through a seasonal change in thermal profile.

14. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Deep lakes have a lower littoral/limnetic ratio; decomposition in the limnetic is limited by the relatively low input of biomass from the littoral zone; oxygen concentrations remain high; water remains clear, and communties remain diverse. These are called oligotrophic systems. Deep lakes in the temperate zone proceed through a seasonal change in thermal profile. Lakes accumulate sediment and fill in, with vegetation encroaching

16. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Deep lakes have a lower littoral/limnetic ratio; decomposition in the limnetic is limited by the relatively low input of biomass from the littoral zone; oxygen concentrations remain high; water remains clear, and communties remain diverse. These are called oligotrophic systems. Deep lakes in the temperate zone proceed through a seasonal change in thermal profile. Lakes accumulate sediment and fill in, with vegetation encroaching Rooted plants can draw nutrients from the benthos and remobilize it before it leaves the system; particularly phosphorus that can be limiting in freshwater systems. This remobilization can accelerate the eutrophication of lakes.

17. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds Deep lakes have a lower littoral/limnetic ratio; decomposition in the limnetic is limited by the relatively low input of biomass from the littoral zone; oxygen concentrations remain high; water remains clear, and communties remain diverse. These are called oligotrophic systems. Deep lakes in the temperate zone proceed through a seasonal change in thermal profile. Lakes accumulate sediment and fill in, with vegetation encroaching Rooted plants can draw nutrients from the benthos and remobilize it before it leaves the system; particularly phosphorus that can be limiting in freshwater systems. This remobilization can accelerate the eutrophication of lakes. This pumping action has less impact on a large deep lake.

18. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds B. Streams and Rivers These are dynamic and constantly changing environments

19. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds B. Streams and Rivers These are dynamic and constantly changing environments

20. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds B. Streams and Rivers These are dynamic and constantly changing environments Production and decomposition can be spatially separated...

21. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds B. Streams and Rivers These are dynamic and constantly changing environments Production and decomposition can be spatially separated... decomposition nutrient transfer productivity

22. Aquatic Biomes I. Freshwater Habitats A. Lakes and Ponds B. Streams and Rivers These are dynamic and constantly changing environments Production and decomposition can be spatially separated... And we often see downstream succession from "oligotrophic" cold, low productivity streams to "eutrophic", highly productive rivers.

23. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats

24. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries

25. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm

26. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load

27. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load - nutrient rich from decomposition

28. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load - nutrient rich from decomposition - highly productive

29. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load - nutrient rich from decomposition - highly productive - nursery area for oceanic fish

30. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load - nutrient rich from decomposition - highly productive - nursery area for oceanic fish - storm buffer

31. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load - nutrient rich from decomposition - highly productive - nursery area for oceanic fish - storm buffer - shellfish and benthos are productive

32. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - shallow and warm - nutrient rich, from sediment load - nutrient rich from decomposition - highly productive - nursery area for oceanic fish - storm buffer - shellfish and benthos are productive - filter water of impurities

33. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - mangroves in the tropics

34. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - estuaries - salt marsh in temperate

35. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs

36. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat

37. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat - dominated by 'reef-building' corals

38. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat - dominated by 'reef-building' corals - nursery area for fish

39. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat - dominated by 'reef-building' corals - nursery area for fish - storm buffer

40. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat - dominated by 'reef-building' corals - nursery area for fish - storm buffer - filter water (a little), but more dependent ON clear water

41. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat - dominated by 'reef-building' corals - nursery area for fish - storm buffer - filter water (a little), but more dependent ON clear water

42. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - coral reefs - most diverse marine habitat - dominated by 'reef-building' corals - nursery area for fish - storm buffer - filter water (a little), but more dependent ON clear water - Zooxanthellae are critical here... the water carries few dissolved nutrients - productivity and diversity is dependent upon photosynthetic symbionts in the coral, itself.

43. Aquatic Biomes I. Freshwater Habitats II. Marine Habitats - Upwellings and the open ocean I mentioned at the end of class that open oceans are "biological deserts" because the source of nutrients (from decomposition at the bottom of the ocean) is a long way from the euphotic zone... so algae are starved of nutrients and productivity is low. The exception is where, as a consequence of the shape of the ocean basin or surface currents or islands, water from the depths is brought to the surface.... this is called an "upwelling" and it is a local productive area.

44. Equator 30 S Surface currents are offshore, and deep water comes up along the coast to "fill the gap". This brings nutrients up, and that's why Peru has the worlds largest and most productive anchovy fishery.

45. Georges Bank - shallow continental shelf, and the offshore Gulf Stream pulling surface waters offshore

46. surface water stripped from island, and deep nutrient-rich water takes its place. in the photo above, red isn't heat... it is algal productivity.

47. surface water stripped from island, and deep nutrient-rich water takes its place. so upwellings are a strong indication that surface ocean waters are usually starved of nutrients.