Introduction to Estuarine Gradients Activity Overview — Transcript

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1. 0:00Hi there, I'm Dr. Jeff Ashley and in
2. 0:02this activity, we'll be exploring
3. 0:05estuary gradients. Remember from our
4. 0:08video lecture that estuaries are
5. 0:10semi-encclosed body of waters where
6. 0:12fresh water meets salt water. Here we
7. 0:14have a depiction of this called the
8. 0:16Clark estuary. Our fresh water would be
9. 0:18coming in from our river here on our
10. 0:21left, entering this semi-encclosed water
11. 0:23body where that fresh water would meet
12. 0:26the salt water. So the ocean is here off
13. 0:28to the right. It would be great if we
14. 0:30could take a boat and sample, but we're
15. 0:33going to do that virtually. So, let's
16. 0:35get
17. 0:36started. In this activity, you'll be
18. 0:39looking at eight sampling sites that
19. 0:41range from the head of the estuary,
20. 0:44which is the start of the river, to the
21. 0:47mouth of the estuary, which is where it
22. 0:49meets the ocean. You're going to be
23. 0:51measuring and accumulating data on three
24. 0:54parameters. The first parameter is
25. 0:57called suspended sediment. We've
26. 0:59discussed this before, especially when
27. 1:01we talked about sea whiffs data and the
28. 1:04color of the ocean. We said sometimes
29. 1:06that land-based activities like runoff
30. 1:09could take some of that sediment
31. 1:11material from the land and put it into
32. 1:13the water body. That's essentially what
33. 1:15suspended sediment is. All of these
34. 1:18particles, some of them large particles,
35. 1:21but mostly fine particles that are
36. 1:23suspended in the water, they essentially
37. 1:26cloud the water, making it turbid or
38. 1:29cloudy. The more suspended sediment you
39. 1:32have, the cloudier the water will look.
40. 1:34Remember that we discussed a great
41. 1:36method when you're in the field for
42. 1:37looking at turbidity or cloudiness was
43. 1:40the use of the SEI disc. Here along
44. 1:44these eight sampling stations, one liter
45. 1:47of water has been collected. You'll be
46. 1:50evaluating the suspended sediment
47. 1:52concentration by a colormetric visual
48. 1:55inspection. That is, you'll be comparing
49. 1:57the color of the sample of water to this
50. 2:00spectrum, which will allow you then to
51. 2:02match the color and then evaluate the
52. 2:05concentration of suspended sediments.
53. 2:07Evaluating suspended sediment
54. 2:09concentrations in water is really
55. 2:11important. High suspended sediments,
56. 2:13that means a whole bunch of suspended
57. 2:15sediments throughout your water column,
58. 2:17impede the ability of phytolanton to
59. 2:20photosynthesize because they shade some
60. 2:22of that photosynthetic radiation coming
61. 2:25down. Clearer water allows more light to
62. 2:28penetrate. Phytolankton love that.
63. 2:30Phytolankton need, as I said before, two
64. 2:32things. They need sunlight to
65. 2:34photosynthesize, but they also need
66. 2:36nutrients. So in this example, you would
67. 2:39match the color of your sample to this
68. 2:41spectrum here to determine the
69. 2:43concentration of suspended sediments.
70. 2:45Then you would record that in your data
71. 2:46sheet. The second parameter that you'll
72. 2:49be evaluating is nutrient concentration.
73. 2:51As I just said, phytolankton need
74. 2:53sunlight. That's great. And they also
75. 2:56need nutrients. Nutrients are primarily
76. 2:58phosphorus and nitrogen containing
77. 3:00compounds, but we'll just group them
78. 3:02together and call it nutrient
79. 3:03concentration. Here you'll count up the
80. 3:06nutrient discs 1 2 3 4 5 6 and realize
81. 3:11that each of these discs represents a
82. 3:13concentration of 0.05 mg per liter. If
83. 3:17you have six of them, you would multiply
84. 3:19six
85. 3:20by 05 mg per liter and come up with the
86. 3:24total concentration for nutrients in the
87. 3:26water. Where do nutrients come from? A
88. 3:29lot of the nutrients in east estuaries
89. 3:31come from runoff from land-based
90. 3:34activities such as agriculture or
91. 3:36wastewater treatment plants.
92. 3:38Phytolankton need these nutrients. So
93. 3:42the next parameter follows
94. 3:44that. You'll be evaluating phytolanton
95. 3:47concentration by counting up the number
96. 3:49of phytolanonic icons or little discs in
97. 3:52each of the
98. 3:53beaker. Let's go through an example.
99. 3:56Here's a sample here with 1 2 3 4 5 6
100. 4:01seven phytolantonic
101. 4:04icons. Each of these icons, although
102. 4:07they're different, represents 100,000
103. 4:10cells per liter. Since we have seven in
104. 4:13this particular sample, we would
105. 4:15multiply 7 by 100,000 cells per liter to
106. 4:19get a total phytolanton phyto
107. 4:22phytolantonic concentration of 700,000
108. 4:25cells per liter. Okay, now that we know
109. 4:28what we're doing and how we garner the
110. 4:30data for this activity, I want you to
111. 4:32read the introduction. It's short, but
112. 4:34it's going to go through a little more
113. 4:36detail on what suspended sediment
114. 4:38concentrations are, what nutrient
115. 4:39concentrations are, and what phytolanton
116. 4:41concentrations are. And then using the
117. 4:44data from each one of these eight sites,
118. 4:47you'll accumulate a data set. You'll do
119. 4:49some plots and you'll do some
120. 4:50interpretations of those data. You'll be
121. 4:52using this PowerPoint. This PowerPoint
122. 4:54is interactive. So, if you click on site
123. 4:57one or site two, it'll take you directly
124. 4:59to the data set. Or you can just follow
125. 5:02along sequentially here as we go
126. 5:05through. All right, have fun with this.
127. 5:07I hope you enjoy it. It's the second
128. 5:09best thing to being in the field. So,
129. 5:12this is a great opportunity for you to
130. 5:14work with some real data and look at
131. 5:16what happens along the gradients of
132. 5:18estuaries.