Lab 8.3

Lab 8.3 – Can wind direction data help us synthesize our observations from Activity 8.1 and 8.2?

Fundamental concept: Relate wind direction to variation in temperature and dissolved oxygen
Estimated time to complete: 45 minutes
Data skills preparation: Lab 2.1 – Time series
Materials needed: None

In the previous two activities, we examined DO and seawater temperature and identified patterns of how they correlate with each other. By this point you probably have formulated some hypotheses as to what is happening to kill the crabs. In this activity we will add a third variable, northward wind speed. We will try to synthesize all of our observations to make a comprehensive hypothesis to explain why the crabs died.

The terminology used to describe wind direction can be confusing. We can refer to the direction the wind is blowing from (as meteorologists and weather forecasters typically do), or we can describe the direction the wind is blowing towards (which is more common in oceanography). So wind that blows from the south toward the north can be called a southerly wind or a northward wind. Remember that wind blowing parallel to the coast will cause upwelling or downwelling near the coast (review the introduction to Lab 8 if you need a refresher).

Use the graph to answer the following questions. When you hover over a data point, a box will pop up with more information. You can zoom in and out of areas of the graph using the slider bar. Note that the wind data only shows the part of the wind parallel to the shore. Positive values (in blue) indicate wind blowing toward the north (northward), and negative values (in red) indicate wind blowing toward the south (southward).

 

 

Quick Check Questions

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Interpretation Questions

1. Do you see any correlation between wind direction and dissolved oxygen? If so, characterize the relationship.
2. Do you see any correlation between wind direction and temperature? If so, characterize the relationship.
3. Summarize what happened with all three variables over the course of the study interval. When one variable changed, how did the other variables change? Were the changes predictable?
4. If the wind is blowing towards the north, which is most likely to occur along the coastline of Oregon, upwelling or downwelling? Explain your reasoning.

Application Question

5. Now synthesize what you have learned from the datasets over the three activities:
   1. What killed the crabs and what was the sequence of events that caused it to happen?
   2. Can we use our understanding of this scenario to help predict when this crab-killing sequence of events might happen in the future in this area? What types of conditions would you need to look out for?

Reflection Questions

6. Think of other commercially important species that might be affected by similar events.  List two species (or types of organisms) affected and describe why and how you think they would be affected by low dissolved oxygen.
7. In the wake of hypoxic or anoxic events, should humans enact regulations to help marine populations recover? What types of regulations?

Real World Application

People depend on seafood as part of their diets, especially in coastal communities.  In Oregon, the fishing industry produced over 144 million dollars in 2016, and kept countless people employed. The most profitable animal harvested is the Dungeness crab. Hypoxic and anoxic events can have an economic impact on coastal communities by harming businesses and causing the price of seafood to increase as the supply of seafood to be harvested dies off.