MIT Invitational — Water Quality

Water Quality · Division C · MIT Invitational · 2021

117 questions · 210 points · 50 min· 4 questions from the original omitted

If at any point, Scilympiad is having trouble saving longer answers (short answer, etc.) please email your response to scioly@mit.edu with the title "[Team #]-[Event Name]-[Question #]" with any other details identifying the question in the body of the email.

PassageFor questions 1, 2a, 2b

Use this table to answer questions 1-2

Question 1

5 pts

Calculate Jaccard's Index for coral reef ecosystems A and B to three decimal places. Show all of your work. Explain what the value represents and how a scientist can use the data within their research of these two locations.

Question 2a

1 pt

Explain how each of these ecological computations can be used by a scientist to understand similarities between ecosystems: Morisita's Overlap Index

Question 2b

1 pt

Explain how each of these ecological computations can be used by a scientist to understand similarities between ecosystems: Renkonen Index

PassageFor questions 3–8

The food web below, consisting of every organism in the ecosystem, is used for questions 3-8

Question 3

1 pt

If phytoplankton receive 456000J of energy from the sun, how much energy would the Great White Shark receive, in kJ? Please leave off the units in your written answer. If the value is less than zero, include a '0' before the decimal place (e.g. write one-tenth as '0.1', not '.1'

Question 4

1 pt

Which organism would be considered the primary producer?

Question 5

1 pt

What is the name of the law used to describe the transfer of energy within this ecosystem? Make sure you write your answer using letters if the answer contains numbers

Question 6

2 pts

Describe why a Shrimp would assimilate a smaller proportion of energy from the Zooplankton than the Great White Shark would assimilate from the Tuna

Question 7

1 pt

An additional organism is introduced into this ecosystem. It is described as a secondary consumer. Which organism will it compete with for the same prey item?

Question 8

1 pt

An additional organism is introduced into this ecosystem. It is described as a secondary consumer. Which organism will it consume?

PassageFor questions 9–17

A manager of a potable water treatment facility has to balance a variety of factors in order to minimize issues that occur during operations. Match the factor (answer choices) with the problems that arise from them. Write the letter of the answer in the box. Answers can be used once, more than once, or not at all. Each question is worth (1) point.

a. Poor Primary Classification b. Hydraulic Overload c. Nitrification d. Organic Overload e. Organic Underload f. Nutrient Shortage

Question 9

1 pt

Lowest pH

Question 10

1 pt

Rising sludge

Question 11

1 pt

Highest Energy Use

Question 12

1 pt

Filamentous bacteria

Question 13

1 pt

Poorest effluent quality

Question 14

1 pt

Plugging

Question 15

1 pt

Highest Chlorine Demand

Question 16

1 pt

Lowest DO Levels

Question 17

1 pt

Standing Water

Question 18

5 pts

Describe the process of Ekman transport and how this phenomena relates to upwelling

Question 19

8 pts

Describe the term 'foraging arena' and explain how the concept of an optimal forager relates to the foraging arena

Question 20

1 pt · select all that apply

Select all of the following which are metals with maximum contaminant levels in water as designated by the EPA

Question 21

5 pts

Describe the 'Deserts of the Ocean.' Where are these systems located? Describe what processes contribute to the formation of these 'deserts.'

Question 22

1 pt · select all that apply

Select the option(s) in which a crepuscular feeder would most likely feed

Question 24

6 pts

What is the deep scattering layer? How was this discovered? What ecological phenomena does the deep scattering layer show?

Question 25

1 pt

The EPA creates a Contaminant Candidate List every ____ years. Use a numeric value (e.g. '0' instead of 'zero')

PassageFor questions 26–28

For Questions 26-28, identify whether the potable water treatment facility should use sulfate-reducing bacteria (SRB), oxidation ditches, or extended aeration

Question 26

1 pt

Located in an area with harsh weather conditions, able to denitrify waste, and able to continue operations when shock occur

A. sulfate-reducing bacteria (SRB)B. oxidation ditchesC. extended aeration

Question 27

1 pt

Easy to operate and install, infrequent disposal of sludge, and a small ecological footprint

A. sulfate-reducing bacteria (SRB)B. oxidation ditchesC. extended aeration

Question 28

1 pt

The owner wants to be able to operate the facility remotely and treat toxic waste streams. She also want to deal with the removal of phosphorus

A. sulfate-reducing bacteria (SRB)B. oxidation ditchesC. extended aeration

Question 29

2 pts

A high KH indicates a high presence of two polyatomic ions in water. What are they?

Question 30

1 pt

True or false: Volcanoes, geysers, and hot springs will cause the water in the surrounding area to become more alkaline

TrueFalse

Question 31

1 pt

Which of the following options orders the steps of the predation cycle in the correct order?

A. Search, encounter, detect, attack, digest, eatB. Search, encounter, detect, attack, eat, digestC. Encounter, search, detect, attack, digest, eatD. Encounter, search, detect, attack, eat, digestE. Search, detect, encounter, attack, eat, digestF. Search, detect, encounter, attack, digest, eat

Question 33

1 pt

Most marine biodiversity is found in which area of the water column?

Question 34

1 pt · select all that apply

Which ions are found with concentrations greater than 10⁻³ molarity in seawater?

Question 35

1 pt

This map shows common occurrences of Karenia breve, a harmful algae. Which type of toxin is produced by this organism and what is the name of the human health effect that goes along with it?

A. Brevetoxin, Diarrhetic Shellfish PoisoningB. Brevetoxin, Neurotoxic Shellfish PoisoningC. Neuratoxin, Amnesic Shellfish PoisoningD. Neuratoxin: Neurotoxic Shellfish PoisoningE. Karenitoxin, Amnesic Shellfish PoisoningF. Karenitoxin; Paralytic Shellfish Poisoning

Question 36

1 pt · select all that apply

Mangroves are considered a keystone species in many estuarine ecosystems. Which of the following are ecosystem services provided by mangrove forests?

A. Decrease turbidityB. Remove toxins from the waterC. Raise dissolved oxygen levels in the waterD. Increase coastline stabilityE. Reduce creep from storm surges and king tidesF. Serve as a nursery for juvenile fish

Question 37

2 pts

What are the two most likely reasons a septic tank disposal system may fail?

Question 38

1 pt

What is the name of the algae associated with corals?

Question 39

1 pt

Which step in potable water treatment is most vulnerable to algal blooms?

Question 40

2 pts

Identify Organisms A and B

Question 41

2 pts

Describe the relationship between organism A and B

Question 42

1 pt

Describe how Organism B can negatively impact coral reef ecosystems

PassageFor questions 43–47

Use this table for questions 43-47

Question 43

1 pt

Based on the table above, is location A in the Pacific, Atlantic, or in another region around the globe? ("Another region" is sufficient; the specific area does not need to be named.)

Question 44

2 pts

Justify your answer to the previous question

Question 45

1 pt

Based on the table above, is location B in the Pacific, Atlantic, or in another region around the globe? ("Another region" is sufficient; the specific area does not need to be named.)

Question 46

2 pts

Justify your answer to the previous question

Question 47

1 pt

Describe how El Nino cycles can impact populations of algae, particularly algae in the Pyrodinium genus

Question 48

1 pt

What are the three sexual reproductive modes of green algae?

Question 50

1 pt · select all that apply

Vaucheriaxanthin is unique to which fleshy algae group

Question 51

1 pt

Describe the role of chrysolaminarin in Xanthophyta algae

Question 52

2 pts

Describe the role of silica in Xanthophyta algae

Question 53

1 pt · select all that apply

Which two areas are the center of marine fish biodiversity in the world?

Question 54

6 pts

Explain how plate tectonics impacted the movement of aquatic organisms between these two areas from the period of 225mya to today

Question 55

1 pt

What is the common name of Organism C, as stated on the rules

Question 56

4 pts

Describe the feeding of Organism C, as well as place them in a feeding category

Question 57

3 pts

Explain the use of gorgonin in this organism

Question 58

1 pt

This organism would be protected under the Coral Reef Preserve Act of 1966

TrueFalse

Question 59

1 pt

Would you find this organism in the Atlantic, Pacific, or Worldwide

Question 60

5 pts

Describe the Fleshy Macroalgal Index and how ecological conditions can impact the value the index produces, as well as how it is calculated

Question 61

1 pt

What is the common name of the oceanic area that encapsulates the coasts of the Solomon Islands, Malaysia, Indonesia, Papua New Guinea, Timor-Leste, and the Philippines?

Question 62

5 pts

What are the benefits of a secondary male in a hermaphroditic species? How do they differ from primary males?

Question 63

3 pts

Compare and contrast between a protandrous and protogynous species

Question 64

1 pt

What time period is commonly referred to as the 'Age of Fishes?'

Question 65

4 pts

Differentiate between a 'resilient' and 'resistant' organism when it pertains to pressure from fisheries

Question 66

15 pts

Traditionally, studies separate species into r-strategists and k-strategists. However, conventional literature in aquatic sciences use three different categories to place marine species. Name these categories and describe the life history characteristics of these groupings. Using this information, define "resilience" and "resistance", and evaluate whether each category would be considered resilient, resistant, both, or neither to fisheries pressure based on your answer to the previous question.

Question 67

1 pt

What is the common name of organism D, as stated on the rules

Question 68

2 pts

Would Organism D be considered a neritic species? Why or why not?

Question 69

3 pts

Explain the benefit of oscillatory swimming to Organism D

Question 70

1 pt

Would Organism D be considered a generalist or a specialist?

Question 71

1 pt

Explain the role of seagrass beds to this species

Question 72

1 pt

What is the common name of Organism E, as stated exactly on the rules?

Question 73

1 pt

This organism is considered a demersal species. Define the term ‘demersal’

Question 74

1 pt

Organism E stumbles upon a region with lively vegetation and a seafloor full of clay and sandy sediments. This habitat ideal for this organism

TrueFalse

Question 75

1 pt

Once laid, Organism E will guard their eggs until it hatches

TrueFalse

Question 76

1 pt

Organism E is considered a part of a monophyletic group. What is a monophyletic group?

Question 77

2 pts

What is the IUCN? What status was this species given by the IUCN?

Question 78

1 pt

This organism is in the Class Actinopterygii. What does this show about its evolutionary advancedness?

Question 79

3 pts

Differentiate between a holotype, paratype, and neotype

Question 80

1 pt

What is the pH of the equivalence point?

Question 81

1 pt

Based on the graph, a ____ is being titrated with a ____?

Question 82

1 pt

What is the pH at the first equivalence point?

Question 83

1 pt

What is the pH of the second equivalence point?

Question 84

2 pts

Explain why there are two bumps in this titration graph instead of one.

Question 85

1 pt

Based on the graph, a ____is being titrated with a ____ ?

Question 86

1 pt

At what temperature, in Kelvin, is water most dense? Round to the nearest whole number and do not include units in your answer.

Question 87

1 pt

Under normal conditions, aragonite saturation will not exceed ____ Ω in a solution of water.

Question 88

1 pt

An influx of fecal coliform into the Mississippi River is likely a ____ source of pollution

A. pointB. nonpoint

Question 89

1 pt

What are the units for pH?

Question 90

1 pt

What location is commonly used to test the levels of dissolved carbon dioxide (and therefore pH) in the ocean by most international organizations?

Question 91

1 pt

A sample of salt water has a pH of 7.4. What is its pOH? (Mind your significant figures for this and following questions!)

Question 93

2 pts

A sample of salt water has a [H+] of 5.26*10⁻⁸. What is the [OH-]? Ensure sig figs are accurately recorded.

Question 94

2 pts

A sample of salt water has a [H+] of 5.26*10⁻⁸. What is the pOH to two decimal places?

Question 95

3 pts

In one of the ‘deserts of the ocean,’ would you expect high or low light penetration, organic N, and dissolved oxygen? Enter ‘High’ or ‘Low’ into the respective blanks for each analyte

Question 96

2 pts

Homiohaline solutions have a ____ salinity while polyhaline solutions have a ____ salinity

Question 97

2 pts

____ is the condition where dissolved oxygen concentrations in water fall below 30% saturation, which is typically below 2 mg/L

Question 98

9 pts

Describe the zone of hypoxia in the Gulf of Mexico. What causes this zone of hypoxia? Is it seasonal or year-round? Why might the label ‘dead zone’ be misleading?

Question 99

1 pt

____ ____ is the term used to describe when thermal pollution increases the overall health of an ecosystem

Question 100

1 pt

Hydroxyapatite is another name for ____ ____

Question 101

1 pt

What is the current pH of the ocean?

Question 102

1 pt

Salinity influences all of the following properties of water EXCEPT

Question 103

1 pt

Which of the following is NOT a way in which sedimentation pollution can harm fish populations?

A. Clogging fish gillsB. Reducing resistance to dieseaseC. Lowering growth ratesD. Affecting fish egg and larvae developmentE. Impairing digestive system function

Question 104

1 pt

Dissolved oxygen concentrations can be decreased by all of the following EXCEPT

Question 105

1 pt

High levels of fecal coliform in water are associated with all of the following EXCEPT

Question 106

2 pts

What is the difference between a hydrometer and a salinometer?

Question 107

1 pt · select all that apply

Select each option that is used to test for phosphates, if any

A. Jackson Candle MethodB. Vanadomolybdophosphoric Acid MethodC. Stannous Chloride MethodD. Multiple Tube DilutionE. Phenoldisulphonic Acid (PDA) MethodF. Ultraviolet Spectrophotometric Method

Question 108

1 pt

How many times more acidic is a solution of pH 4 than a solution of pH 8? If the answer is 1000 or greater, enter it without a comma (e.g. '1000' instead of '1,000')

Question 109

3 pts

Describe the steps of the Jackson Candle Method

Question 110

1 pt · select all that apply

Pipes are often color-coded to indicate what substance is traveling through them. Select every option that currently matches the pipe color with the substance that passes through it

Question 111

1 pt

The Federal Water Pollution Control Act was amended in 1972 and is now known as the ____ ____ ____. This has made it unlawful to discharge any pollutant from a point source into navigable waters, unless a permit is obtained

Question 112

1 pt

Write the chemical formula for orthophosphate

Question 113

1 pt

What is the EPA-approved method to measure orthophosphate?

Question 115

1 pt · select all that apply

When seawater undergoes evaporation: Which is true?

A. The remaining water becomes more salineB. The proportions of Na and other ions changeC. The proportion of the major ions remain the sameD. The proportion of K to other ions remain constant

Question 116

1 pt

What is the chemical formula for ammonia?

Question 117

1 pt

What ion would be represented by graph A? Please state the ion's full name, not the chemical symbol.

Question 118

1 pt

What ion would be represented by graph B? Please state the ion's full name, not the chemical symbol.

Question 1

Question 2a

Question 2b

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18

Question 19

Question 20

Question 21

Question 22

Question 24

Question 25

Question 26

Question 27

Question 28

Question 29

Question 30

Question 31

Question 32

Question 33

Question 34

Question 35

Question 36

Question 37

Question 38

Question 39

Question 40

Question 41

Question 42

Question 43

Question 44

Question 45

Question 46

Question 47

Question 48

Question 50

Question 51

Question 52

Question 53

Question 54

Question 55

Question 56

Question 57

Question 58

Question 59

Question 60

Question 61

Question 62

Question 63

Question 64

Question 65

Question 66

Question 67

Question 68

Question 69

Question 70

Question 71

Question 72

Question 73

Question 74

Question 75

Question 76

Question 77

Question 78

Question 79

Question 80

Question 81