Monday, August 25, 2008

Changing Behavior: Mitigation in New Orleans post Katrina

From the Times Picayune:

Three years after Hurricane Katrina, houses are still going up across the metropolitan area. And "up" doesn't mean new: It means, well, up.

The sight of homes being raised 3 or 4 or even 10 or 12 feet above ground has become common. But what will this do to the local architectural landscape? What is the impact on neighborhoods? Individual blocks? And how high is too high?
This article discusses a project by the Center for Hazards Assessment, Response and Technology (CHART) at the University of New Orleans.

Early on, Laska says, the group realized that elevation conversation can be complex. The earliest house-raisings post-Katrina often looked like structures on steroids. Laska refers to them as "flood rage houses" -- residences hoisted by people who said, succinctly, "Never again."

In fact, many homeowners lifted their foundations to the level of their Katrina watermarks. Which is actually not such a bad idea, Laska said.

"That kind of reaction is based on actual flood experience. It's a good barometer of what the highest potential flood level might be."

More recent elevations, however, tend to be less severe. "The elevated house has grown on us, and people are doing a better job at it, " Laska said.

It appears that individuals' psychological response to risks has followed patterns discussed previously in academic literature on risk and mitigation. Individuals appear to assign higher probabilities to these risks immediately after the event, thus overcompensating. These people may have raised their homes more because of this experience. As the event becomes more distant in individuals memories, they do not overcompensate as much. This poses the question, will we continue to see less and less mitigating behavior as Katrina becomes a more distant memory?


Here is a link to an interactive map of New Orleans.






Friday, August 15, 2008

Intro Topic: Dead Zones

I am starting a new series of blog posts for students in my intro to coastal management class. These posts will selectively cut parts of news articles to cover critical coastal management issues.

Photo of the dead zone off Louisiana via Time:

A new study has been published in Science concerning dead zones. From the New York Times:

A study to be published Friday in the journal Science says the number of these marine “dead zones” around the world has doubled about every 10 years since the 1960s. About 400 coastal areas now have periodically or perpetually oxygen-starved bottom waters, many of them growing in size and intensity. Combined, the zones are larger than Oregon.

What are dead zones?
Dead zones are hypoxic (low oxygen) or anoxic (no oxygen) marine or estuarine areas. The absence of oxygen threatens the existence of marine life.

How do dead zones develop? From Oceanus:
The most widespread, chronic environmental problem in the coastal ocean is caused by an excess of chemical nutrients. Over the past century, a wide range of human activities—the intensification of agriculture, waste disposal, coastal development, and fossil fuel use—has substantially increased the discharge of nitrogen, phosphorus, and other nutrients into the environment. These nutrients are moved around by streams, rivers, groundwater, sewage outfalls, and the atmosphere and eventually end up in the ocean.

Once they reach the ocean, nutrients stimulate the growth of tiny marine plants called phytoplankton or algae. When the concentration of nutrients is too high, this growth becomes excessive, leading to a condition called eutrophication.
How do dead zones impact marine life? From the NY Times:

“The overwhelming response of the organisms in our coastal areas is to migrate or to die,” Dr. Diaz said. “To adapt to low oxygen water, it has to be a part of your evolutionary history. It’s not something you can develop in a 40- or 50-year time period.”

Many dead zones are cyclical, recurring each year in the summer months. But over time, they can permanently kill off entire species within the zone. They have also prevented the rebounding of species that are under protection after overfishing, like the Baltic Sea’s cod.

Low oxygen levels also kill off annelid worms and other sources of food for fish and crustaceans.

What are some strategies to address dead zones?

From the NY Times
Robert W. Howarth, a professor of ecology and environmental biology at Cornell, said methods to reduce nitrogen-rich runoff existed, including the planting of winter rye or winter wheat rather than leaving fields fallow after fall harvest. Such planting would cause much fertilizer to be absorbed by the winter crops rather than being leached into waterways by spring rains.
From Oceanus
There are some novel ideas as well. A project is currently underway at Woods Hole Oceanographic Institution to examine the feasibility of using shellfish aquaculture to reduce nutrients in the coastal ocean. The experimental shore-based aquaculture system at the National Center for Mariculture in Eilat, Israel, uses shellfish to absorb excess nutrients excreted by fish. Researchers at WHOI are trying to determine whether the same idea is feasible in the ocean. As the shellfish produced by such an enterprise have economic value, this is an example of a win-win situation.


Examples of Dead Zone Websites
Gulf of Mexico Dead Zone
FAO: Effects of Riverine Inputs on Coastal Ecosystems and Fisheries Resources
NOS: Integrated Assessment of Hypoxia in the Gulf of Mexico
USGS: Gulf of Mexico Hypoxic Zone
USGS: Restoring Life to the Dead Zone

Thursday, August 14, 2008

Revisiting a Theme: It Ain't Easy Being a Commercial Fisherman

The NC Division of Marine Fisheries has released their "Trends in North Carolina Seafood Prices." The Outer Banks Sentinel has summarized some of the findings:

For some species, like shrimp, croaker, and bluefish, the average price per pound in 2007 was lower than the price paid more than a decade earlier.

In 2007, shrimp averaged $1.88 per pound, compared to $2.61 in 1994.

Fishermen were paid $0.30 for bluefish in 2007, less than the $0.36 paid in 1995.

Croakers earned fishermen $0.37 per pound in 2007, but brought in $0.51 in 1990.

A direct correlation between growth of the global seafood market and downward spiraling prices for some, if not all, types of wild-caught seafood produced in NC is hard to deny.

The evidence that globalization has hurt NC fishermen is perhaps most compelling in the case of shrimp, one of the most important commercial fisheries in the state.

Unfortunately, as we see in many situations, opening up trade has led to winners and losers. This article does not directly mention the winners, the consumers of seafood. The consumers now have access to a less expensive product. Elsewhere in the global market, someone has a competitive advantage for many of these products.

There is no doubt that commercial fishermen are the losers in these situations, since they experience lower prices and rising costs.

Wednesday, August 13, 2008

Getting Back

After getting through a family tragedy, I am finally getting the blog rolling again. Here is a fitting photo representing my last couple weeks. (HT gcaptain)