Weekly Ocean News

DATASTREME OCEAN WEEK EIGHT: 20-24 March 2006

Ocean in the News:

(Thurs.) Fisheries being robbed -- An international group of experts are attempting to draw public attention to the damage being done to the world's fisheries by "roving bandits", marine-life traders who over-harvest species of fish in regions of the ocean that are not adequately covered by sustainability laws. [National Geographic Society]
(Thurs.) Effects of "cargo sweeping" are to be explored -- The US Coast Guard is to begin a study of the decades old practice of "cargo sweeping" in the Great Lakes that involves dumping the residual materials and the wash water from cargo ships into the Lakes. Although this practice is prohibited by international treaty and federal laws, it remains because of exemptions and a lack of enforcement. [ENN]
(Tues.) A national estuarine research preserve is featured -- A recent NOAA Magazine article features the Guana Tolomato Matanzas National Estuarine Research Reserve located along the coast of northeast Florida near St. Augustine. This preserve, one of the 26 in the NOAA National Estuarine Research Reserve System, uses research and education to help manage the diverse estuarine and coastal habitats of a region of Florida's Atlantic coast that features estuarine lagoons formed by three rivers that give the preserve its name. [NOAA Magazine]
(Tues.) Coral reefs survived major tsunami but may be threatened by building -- Representatives from the World Conservation Union and the Global Coral Reef Monitoring Network warn that although many coral reefs survived the devastating Indian Ocean tsunami of December 2004, these reefs could be threatened by the rebuilding efforts that are currently underway across the Indian Ocean basin. [ENN]
(Tues.) Radar altimetry from space described -- An international group of oceanographers, hydrologists and glaciologists recently attended a symposium organized by the European and French space agencies entitled "15 Years of Progress in Radar Altimetry" that outlined the development of radar altimeters that are placed onboard orbiting satellites. Some of the attendees credited this instrument with revolutionizing the field of physical oceanography. [ESA]
Intense tropical cyclone hits Australia -- A tropical cyclone named Larry that was rated a category 5 on the Saffir-Simpson Hurricane Intensity Scale hit the northeast coast of Australia on Monday (local time). This cyclone, the southwestern Pacific's counterpart to a hurricane, appears to be the strongest cyclone to hit the northeastern Australian coast . Some injuries were sustained and power outages were widespread.. In ordering evacuations along sections of the Queensland coast, emergency management officials were comparing the potential destructive force associated with Tropical Cyclone Larry with that associated with Hurricane Katrina that hit the US Gulf Coast last summer. [CNN]
New displays for real-time coastal information -- NOAA officials recently announced a new version of their nowCOAST Web portal that will allow users to see displays of real-time cloud imagery from geosynchronous satellites superimposed upon current meteorological and oceanographic observations, along with NOAA forecasts. [NOAA News]
Hurricane updates -- The National Hurricane Center has recently released final technical reports on several of last year's hurricanes. Some of the findings that appear in these Tropical Cyclone Reports (which require the Adobe Acrobat reader) include:
- Hurricane Emily that moved across the Caribbean last July was upgraded to a category-5 hurricane (on the Saffir-Simpson Intensity Scale), making it the earliest category 5 system to form in the Atlantic basin and the only one during the month of July. [NHC]
- Hurricane Rita, which made landfall along the southwestern Louisiana Gulf coast in late September 2005, had the fourth-lowest central pressure on record in the Atlantic basin. [NHC]
- Causality statistics for Hurricane Dennis, a category-4 hurricane that made landfall along the Florida Gulf coast last July, were updated to include 42 deaths, with 22 in Haiti, 16 in Cuba, 3 in the US and 1 in Jamaica. [NHC]
Results of hurricane study defended -- Researchers at the Georgia Institute of Technology recently published an updated report in which they have subjected their earlier, and controversial, analysis that rising sea surface temperatures were responsible for the increased worldwide number of high-intensity hurricanes. The conclusion from the newer study is that sea surface temperature dominates other competing factors in affecting the increase hurricane strength. [EurekAlert!]
Sea surface temperature data from satellites are crucial -- A project called Medspiration is providing high resolution nighttime sea surface temperature data collected from the Mediterranean Sea by sensors onboard the European Space Agency's satellites as input to several weather and ocean prediction models. [ESA]
Cruise industry appears to be a good steward -- A recently-released report entitled "From Ship to Shore: Sustainable Stewardship in Cruise Destinations" prepared by the Center for Environmental Leadership in Business of Conservation International indicates that the cruise industry, including cruise line companies, shore operators and local governments, appear to be more environmentally aware and are exercising better stewardship of the environmentally-sensitive cruise destinations. [EurekAlert!]
Global and US Hazards/Climate Extremes -- A review and analysis of the global impacts of various weather-related events, including drought, floods, and storms during the current month. [NCDC]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Loss of Louisiana's Coast

According to the Louisiana Coastal Wetlands Conservation and Restoration Task Force, Louisiana has been losing its coastal wetlands (bayous, marshes, and swamps) to the waters of the Gulf of Mexico at an alarming rate of about 65 to 100 square km (25 to 38 square mi) per year for the past several decades. This loss adversely affects fisheries in the Gulf of Mexico and makes the coastal zone more vulnerable to storm surges such as that produced by Hurricane Katrina in August 2005. Since the early 1930s, the state's coastal wetlands have shrunk by an area equivalent to the state of Delaware. According to USGS estimates, an additional 1800 square km (700 square mi) could be lost by mid-century. The price tag for reversing this trend, restoring some marshes, and protecting the remaining 15,000 square km (5800 square mi) of wetlands could top $14 billion and take decades to complete. Many people argue that the value of Louisiana's coastal wetlands is well worth the expense.

As much as 75% of the fish and other marine life in the northern Gulf of Mexico depend on Louisiana's coastal wetlands. The wetlands are a nursery for commercially important shellfish such as shrimp, crawfish, blue crab, and oysters. It is a food source for larger fish including yellow fin tuna, red snapper, and swordfish. In 2003, about three-quarters of the nation's fish and shellfish catch by weight came from Louisiana's waters. In addition, the wetlands are a stopover for millions of birds migrating between North and Central/South America. Furthermore, wetlands and associated barrier islands protect the ports, buildings, and other coastal zone structures from storm surges. Wetlands are particularly important in buffering the levees surrounding New Orleans, much of which is below sea level.

Many factors contribute to the loss of Louisiana's coastal wetlands. Thousands of kilometers of pipelines transporting oil and natural gas through the marshes plus the extensive network of navigation channels allow saltwater to intrude the wetlands. Increased salinity of the originally fresh or brackish waters kill wetland grasses, shrubs, and other vegetation that anchor soil in place. The canals also allow tidal currents to flow farther inland, accelerating erosion of wetland soils. The most important factor, however, is the consequence of flood control structures (levees) constructed along the banks of the Mississippi River. Levees constrict the flow of the river so that waters and suspended sediment discharge rapidly into the Gulf. Deprived of a continuous input of sediments and vegetation-supporting nutrients, existing sediments compact, wetlands subside and Gulf waters invade the wetlands. With the anticipated continued rise in sea level due to global climate change (discussed in Chapter 12 of your DataStreme Ocean textbook), erosion of Louisiana's coastal wetland may accelerate in the future.

Plans to reverse the loss of Louisiana's coastal wetlands (the Coast 2005 plan and the Louisiana Coastal Area plan) seek to restore the structure and function of coastal wetlands. One proposal is to breach some levees along the lower Mississippi. This partial diversion of the Mississippi would increase the supply of sediments to the wetlands. Closing or installing locks on some navigation canals would reduce saltwater intrusion. In addition, dredged sediment would be used to re-build wetlands and restore barrier islands.

Concept of the Week: Questions

The most important factor contributing to erosion of Louisiana's coastal wetlands is [(saltwater intrusion)(levees along the banks of the Mississippi River)].
Global climate change that is accompanied by a rise in sea level is likely to [(accelerate)(have no effect on)] the rate of erosion of Louisiana's coastal wetlands.

Historical Events:

20 March 2000...A large iceberg measuring approximately 170 mi by 25 mi calved off Antarctica's Ross Ice Shelf near Roosevelt Island. The iceberg was approximately 2.5 times the size of New York's Long Island. (Accord's Weather Guide Calendar)
22 March 1778...Captain James Cook of the British Royal Navy sighted Cape Flattery, in present day Washington State.
22 March 1999...Tropical Cyclone Vance produced Australia's highest measured wind speed of 166 mph at Learmonth, West Australia. Gusts reaching 185 mph were estimated in the eyewall in the Exmouth Gulf. All homes in the village of Exmouth were either damaged or destroyed. (Accord's Weather Guide Calendar)
24 March 1955...The first seagoing oil drill rig (for drilling in over 100 feet of water) was placed in service by the U.S. company C.G. Glasscock Drilling Co. The rig was able to drive piles with a force of 827 tons and pull a pile with the force of 942 tons. (Today in Science History)
24 March 1989...The tanker Exxon Valdez grounded on a reef in Prince William Sound, AK, spilling 10.1 million gallons of crude oil, resulting in the worst oil spill in U.S. history. Coast Guard units responded and prevented the entire cargo from spilling, cleaned up the oil which did spill, and conducted an investigation into the causes of the accident. The spill provided the impetus for the passage of the Oil Protection Act in 1990. (US Coast Guard Historians Office)
25 March 2000...A rouge wave near Shelter Cove, CA swept a lady from a Canadian school group into the ocean. Four members of the group tried to rescue her, but were overcome by the waves and currents. A fishing vessel and the US Coast Guard rescued two of the rescuers. (Accord's Weather Guide Calendar)
26 March 1845...Joseph Francis of New York City patented a corrugated sheet-iron lifeboat. (Today in Science History)
26 March 1946...The International Ice Patrol resumed after being suspended during World War II. (US Coast Guard Historians Office)