Tasks for Section I:
The tasks within Section I of Part C of the Integrated Topics focus on questions that require explanation of the combination of controls on the ocean environment governing the characteristics of marine habitats and thereby exert an influence on the populations and distributions of biota.
Section I: Answer either Question I.1 or I.2 and either Question I.3 or I.4
Questions I.1 and I.2 focus on the influence of on marine biota of the physical properties and chemical characteristics of the ocean environment, respectively
Questions I.3 and I.4 focus on the influence of on marine biota of ocean dynamics and geological materials/processes, respectively
Guidelines for Section I
These tasks require explanations, with examples, of how specific controls on the marine environment related to (a) physical properties or chemical characteristics and (b) ocean dynamics or geological materials/processes affect the populations and distributions of marine biota. Answers (~80-150 words) should identify key controls within the theme and cite specific instances of how adaptations of organisms are reflected by their populations and distributions in response to these controls on ocean environments.
Strong answers will identify specific characteristics within the theme, describe their influence on ocean environments, and explain how specific organisms reflect or have responded to such effects, especially in terms of adaptations to particular habitats and lifestyles. For example, for Question I.1 the adaptations of deep-sea fish provide evidence of their response to living in the aphotic zone, whereas for Question II.3 the Coriolis force exerts an influence on ocean circulation, generating regions of upwelling which favor phytoplankton, such as diatoms, that require abundant nutrients and sustain organisms within higher trophic levels sustained by this productivity.
Tasks for Section II: Modification in Controls on Marine Biota linked to Climate Change
Section II focuses on the task of answering one question from four options – II.5-8 – that explore how climate change may affect physical parameters, chemical characteristics, ocean dynamics or geological materials/processes (as examined in I.1, I.2, I.3 and I.4, respectively) leading to modifications in oceanic environments that may affect the populations and distributions of marine biota.
Section II: Answer either Question II.5, II.6, II.7, or II.8
II.5-8 all focus on how climate change may modify controls on marine biota – specifically in terms of one of the themes considered in Section I
There is also a bonus Task (3 points), which is to complete another of the four options (II.5–8).
Guidelines for Section II
Explain how the specific characteristics of the one of four themes from Section I (physical parameters – I.1, chemical characteristics – I.2, ocean dynamics – I.3, and geological materials or processes – I.4) may be modified by climate change, discussing the consequence for marine organisms and/or their habitats. Answers (~80-150 words) should consider an aspect of climate change (e.g., increased temperatures, increased CO2, higher sea level, increased sediment discharge resulting from accelerated water cycle) and explain how the resultant environmental changes will likely impact the populations and/or distributions of marine organisms. (5 points)
Strong answers will discuss how an individual theme can be modified by a change in climate, describing the subsequent effect on ocean environments, and explaining how the populations and/or distributions of particular organisms would likely be affected by that change, especially in terms of impacts on individual habitats and lifestyles, citing specific examples.
Section I:
(a) This task focuses on explanation of the combination of controls on the ocean environment that govern the characteristics of marine habitats and thereby exert an influence on the populations and distributions of biota. Answer ONE of the two questions I.1 or I.2. (10 points)
I.1. Describe examples of physical parameters (e.g., temperature, light availability) that exert controls on the ocean environment explaining how these factors influence the distributions of marine biota, citing examples of the organisms, or their adaptations.
The most obvious connection between light availability and ocean environment is the amount of plant growth that is possible. Since plants use light to complete photosynthesis, the more light plants can absorb, the more energy they will be able to produce. Therefore, there are a higher number of plants in depths of water that allow light to penetrate. The plants also act as food for other marine life like fish and other creatures, so where there are more plants, there will be more fish. Where there are more fish, there will be more predators, and so on. Where the water is deeper and there is less or no sunlight, there will be fewer or no plants, and fewer fish. The amount of sunlight has a huge effect on the amount of fish at a given depth of the ocean.
I.2. Describe examples of chemical characteristics (e.g., nutrients, salinity, CO2, O2) that exert controls on the ocean environment explaining how these factors influence the distributions of marine biota, citing examples of the organisms, or their adaptations.
(Write your answer here)
(b) This task focuses on explanation of the combination of controls on the ocean environment that govern the characteristics of marine habitats and thereby exert an influence on the populations and distributions of biota. Answer ONE of the two questions I.3 or I.4. (10 points)
I.3. Describe examples of ocean dynamics (e.g., currents, waves, tides) that exert controls on the ocean environment explaining how these factors influence the distributions of marine biota, citing examples of the organisms, or their adaptations.
Currents, such as upwelling, have a huge effect on marine life. We established that most plants and fish live near the surface of the water where there is more light, but the nutrients and organic materials that they also need sink to the bottom of the ocean. Upwelling currents bring those nutrients up near the surface so that they can be consumed. Likewise, there are things missing from the bottom of the ocean that those biota need as well, such as oxygen. Downwelling currents take the oxygen from the surface and bring it down to the bottom of the ocean to be consumed by those organisms.
I.4. Describe examples of geological materials or processes (e.g., sediment substrate, hydrothermal fluids, plate tectonics) that exert controls on the ocean environment explaining how these factors influence the distributions of marine biota, citing examples of the organisms, or their adaptations.
(Write your answer here)
Section II:
This task (Questions II.5-8) again considers how a combination of controls on the ocean environment governs the characteristics of marine habitats and thereby exerts an influence on the populations and distributions of biota. If differs from the subgroup tasks by focusing on the impact of climate change on these themes. Answer ONE question, either II.5 or II.6 or II.7 or II.8. (5 points)
Context:
The subgroup tasks focused on how specific controls on the marine environment related to the four different themes (physical parameters, chemical characteristics, ocean dynamics & geological materials or processes) affect the populations and distributions of marine biota, namely:
II.5. Physical parameters (e.g., temperature, light availability) exerting controls on the ocean environment influencing the distributions or adaptations of marine biota.
II.6. Chemical characteristics (e.g., nutrients, salinity, CO2, O2) exerting controls on the ocean environment influencing the distributions or adaptations of marine biota.
II.7. Ocean dynamics (e.g., currents, waves, tides) exerting controls on the ocean environment influencing the distributions or adaptations of marine biota.
II.8. Geological materials or processes (e.g., sediment substrate, hydrothermal fluids, plate tectonics) exerting controls on the ocean environment influencing the distributions or adaptations of marine biota.
Ocean dynamics, such as currents, control the population and distribution of oxygen and nutrients to organisms in the ocean. Upwelling currents bring nutrients like nitrogen and phosphate to the surface which allow krill in the Antarctic region to flourish. Likewise, downwelling currents bring oxygen down to the ocean floor which allows for the basic survival of organisms in deep waters.
Bonus Task:
Provide an answer for a second question from the four options (II.5, II.6, II.7, or II.8), discussing and explaining how its specific characteristics may be modified by climate change and discussing the consequence for marine organisms and/or their habitats. (3 bonus points)
Physical parameters, like temperature and light availability, control the availability of nutrients for primary producers that use photosynthesis and fuel the food web. Temperature dictates the level at which organisms can live. Light availability influences the adaptations necessary for creatures, like anglerfish, to live with limited light levels. Climate change alters the temperature of ocean waters and thus the environment organisms must live in. Temperature change vastly changes habitats of the creatures living within them.
Resources
Atmospheric CO2
The approach examination of time series data for atmospheric CO2 concentrations at Mauna Loa, Hawai’i. The website for these data is (Mauna Loa CO2 (Links to an external site.)) presents a graph of changes in CO2 over the past five years together with values from one year ago. There are a series of tabs above these data that display temporal changes in atmospheric CO2 concentrations over different time periods and show the growth rate of CO2. Several of the plots accessed using these tabs are useful in the context of this question, namely:
- Full Record: (Links to an external site.) Full Mauna Loa CO2 record: long-term trend in monthly values for atmospheric CO2 concentrations at Mauna Loa since measurements began in 1958 (red line) and seasonally corrected data (black line). A similar record for Global CO2 can be viewed by selection of the global tab, although it begins in 1980.
- Growth Rate (Links to an external site.): Annual mean growth rate for Mauna Loa, Hawaii: a histogram of the annual increase in atmospheric CO2concentrations at Mauna Loa since measurements began in 1958 (turquoise bars) and decadal averages (black lines). The global data is presented as a table of values, with 3.00 ppmv measured for 2016, 1.89 ppmv measured for 2017, and 2.86 measured for 2018.
- Last 1 Year (Links to an external site.): This webpage is titled Up-to-date weekly average CO2 at Mauna Loa presents a plot of measures of CO2 over the past year plus two other useful sets of data for this assignment, namely (i) The CO2 concentration for April 7 2019 the value is 413.13 ppm), values for April 7 2018 (409.46 ppm), and 10 years ago (389.50 ppm). .
The exercise requires choice of specific scenarios for prediction of future atmospheric CO2 concentrations, arising from, for example, (i) continuation of current annual increases, or (ii) continued growth in the annual rate of CO2 increases, or (iii) a reversal of the trend for increases in the annual rate of growth of CO2 increases to a decline at some time in the future.
These and other scenarios can be computed using the optional spreadsheet, namely:
The spreadsheet also provides two other multi-decadal scenarios:
- Rows 12 – 17 reproduces the observed record for Mauna Loa by using the decadal averages for annual increases in atmospheric CO2 concentrations.
- Rows 22 – 26 project future increases in atmospheric CO2 concentrations based on a 5% decadal reduction in CO2 emissions beginning in 2029.
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