Weekly Ocean News

WEEK EIGHT: 27-31 October 2008

Opportunity for Teachers: The National Ocean and Atmospheric Administration's (NOAA) Teacher at Sea 2009 Field Season program is now accepting applications until 31 December 2008. Gain your "sea legs" and first-hand experience in one week to one month voyages. For more information, or to apply, see http://teacheratsea.noaa.gov.

Ocean in the News:

Eye on the tropics --Organized tropical activity was relatively light this past week:
- No organized tropical cyclone activity occurred during this past week in the North Atlantic basin.
- In the eastern North Pacific basin, Tropical Depression 17-E formed during midweek off the southwest coast of Mexico, but dissipated within two days after traveling to the northwest. Additional information on this depression can be found on the NASA Hurricane Page.
- In the North Indian Ocean basin, Tropical Cyclone 3B formed early last week over the Arabian Sea and traveled to the northwest, entering the Gulf of before making dissipating along the coast of Yemen. This cyclone brought torrential rain to arid Yemen. An image made from the MODIS sensor on NASA's Terra satellite last week shows the clouds surrounding Tropical Cyclone 3 over the Gulf of Aden. [NASA Earth Observatory] Additional satellite imagery and information appears on the NASA Hurricane Page.
  At the start of this week, Tropical Cyclone 4B developed over the Bay of Bengal and was heading north toward Bangladesh.
- In the central South Indian Ocean, Tropical Cyclone 1S, also named Tropical Cyclone Asma formed and traveled to the southwest, dissipating by late in the week. Additional information and satellite images are available on the NASA Hurricane Page for this tropical cyclone, which is a somewhat rare event giving that this time of year is spring in the Southern Hemisphere.
New Jersey dolphins to be monitored -- NOAA’s Fisheries Service recently released a plan that would monitor 12 bottlenose dolphins in New Jersey's Shrewsbury and Navesink Rivers, estuaries close to the New York City metropolitan area. Officials also announced that no current efforts would be made to force the dolphins out of the area. [NOAA News]
Research ship fleet upgrade plan announced -- The NOAA Administrator recently announced that his agency has completed a detailed plan to modernize its marine operations by replacing nine sea-going research ships and refurbishing a tenth within the next 15 years. Since 2001, nine new vessels have been commissioned, with two additional ships scheduled to enter the service by late 2009. [NOAA News]
White abalone recovery plan is completed -- NOAA’s Fisheries Service recently released its final recovery plan for the endangered white abalone, a marine mollusk that frequented the coastal waters of southern California and Mexico's Baja California Peninsula. Under this plan, NOAA scientists will work with other federal agencies, the state of California and the Mexican government. [NOAA News]
National study of ocean acidification is commissioned -- Officials with NOAA and the National Science Foundation recently announced that the first comprehensive national study has been commissioned to see how carbon dioxide emissions absorbed into the oceans may be altering fisheries, marine mammals, coral reefs, and other natural resources. [NOAA News]
Field experiment studies Southeast Pacific climate system -- An international team of researchers from the United Kingdom, the United States and Chile are participating in VOCALS (VAMOS Ocean Cloud Atmosphere Land Study) a month-long field campaign off the Chilean coast designed to sample clouds and aerosols, as well as to measure air-sea-land interactions over the Southeastern Pacific and along the coast, which would ultimately help the researchers improve their global and regional climate models. [National Centre for Atmospheric Science]
Circumpolar research cruise completed --The German Research Vessel Polarstern recently returned to its home port of Bremerhaven after conducting a two-month and 10,800 nautical mile research cruise that made it the first research vessel to travel around the North Pole as it passed through the Northeast and Northwest Passages. An international group of 47 researchers were aboard the 23rd Arctic expedition of the Polarstern. [EurekAlert!]
Harbor seals damaged by mercury pollution -- Several Belgium scientists have determined that exposure to methylmercury from anthropogenic and natural sources appears to be more damaging to harbor seals than previously thought. [EurekAlert!]
Sea life threatened by fertilizers -- A professor at Johns Hopkins University who has studied the changes in the sediments at the bottom of Chesapeake Bay warns that increased use of fertilizers along with other human activities has caused changes to the nitrogen cycle, resulting in damage to both water quality and aquatic life. [Springer]
Ancient ocean circulation patterns studied -- Researchers at the University of Missouri and University of Florida have been using a chemical tracer in ancient fish to study the circulation regime in the North Atlantic Ocean during the Late Cretaceous, a time more than 65 million years ago marked by high temperatures and atmospheric levels of carbon dioxide. [University of Missouri News]
An All-Hazards Monitor -- This Web portal provides the user information from NOAA on current environmental events that may pose as hazards such as tropical weather, marine weather, tsunamis, rip currents, Harmful Algal Blooms (HABs) and coral bleaching. [NOAAWatch]
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 catches of 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 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:

27 October 1728...Captain James Cook, the famed British naval officer who was one of the first of the scientific navigators, was born on this date. Captain Cook surveyed the coasts of Labrador and Newfoundland before making three expeditions into the Pacific Ocean where he became the first Englishman to explore previously uncharted locations. On his various voyages, he conducted astronomical observations and his ship's botanist studied the flora and fauna that were collected. (Today in Science History)
28 October 1492...The famous Italian explorer, Christopher Columbus, landed on Cuba. (Wikipedia)
28 October 1991...Typhoon Thelma devastated the Philippines. Reports indicated that 6000 people died by catastrophic events related to the storm including dam failure, landslides, and extensive flash flooding. The greatest number of casualties occurred on Leyte Island where an 8-ft storm surge struck Ormoc, accounting for over 3000 fatalities. (The Weather Doctor)
29 October 1999...Tropical Cyclone 5B, with sustained winds of 155 mph, made landfall at Paradwip (Orissa, India). A storm surge of at least 20-ft height swept at least 12 mi inland. More than 10,000 people were killed. With 2 million homes either damaged or destroyed, 35 million people were left homeless. Damage from this tropical cyclone was $1.5 billion. (Accord Weather Guide Calendar)
30 October-1 November 1991...After absorbing Hurricane Grace on the 29^th, an intense ocean storm took an unusual course and moved westward along 40 degrees north latitude and battered eastern New England with high winds and tides. Winds had already been gusting over 50 mph along the coast 2 days before, so seas and tides were very high. Major coastal flooding and beach erosion occurred all along the New England, New York, and New Jersey coasts. Over 1000 homes were damaged or destroyed with tides 4 to 7 ft above normal. Wind gusts reached 78 mph at Chatham, MA and 74 mph at Gloucester, MA. A ship east of New England reported a 63-ft wave. Total damage from the storm was $200 million. On 1 November this ocean storm underwent a remarkable transformation. Convection developed and rapidly wound around the storm center and an eye became visible on satellite imagery. Air Force reconnaissance aircraft found a small but intense circulation with maximum winds of 75 mph. This evolution from a large extratropical low to a small hurricane is rare but not unprecedented. (Intellicast)
31 October 1874...A waterspout (a tornado-like vortex that travels over water) formed over Lake Erie and reached the lakeshore approximately 0.5 mi west of Buffalo, NY. Upon reaching the shore, it dissipated, scattering sand in all directions. (Accord Weather Guide Calendar)
31 October 1876...A 10 to 50 ft storm surge ahead of the Backergunge cyclone flooded the eastern Ganges Delta in India (now Bangladesh). Over 100,000 people drowned. (The Weather Doctor)
1 November 1521...Four ships in the fleet commanded by the explorer Ferdinand Magellan began sailing through the passage immediately south of mainland South America connecting the Atlantic and Pacific Oceans, now known as the Strait of Magellan. Because this passage began on All Saints Day, Magellan initially called the 373-mile long passage, the Estreito (Canal) de Todos los Santos , or "All Saints' Channel". (Wikipedia)
1 November 1755...Lisbon, Portugal was destroyed by a massive earthquake and tsunami, killing between 60,000 and 90,000 people. (Wikipedia)
1 November 1859...The current Cape Lookout, NC lighthouse was lit for the first time. Its first-order Fresnel lens can be seen for nineteen miles. (Wikipedia)
1 November 1861...A hurricane near Cape Hatteras, NC battered a Union fleet of ships attacking Carolina ports, and produced high tides and high winds in New York State and New England. (David Ludlum)
1 November 1884...Greenwich Mean Time (GMT) was nearly unanimously adopted at a meeting of 25 nations at the International Meridian Conference in Washington, DC. This time is also called Greenwich Meridian Time because it is measured from the Greenwich Meridian Line at the Royal Observatory in Greenwich, England. At that time, the International Date Line was also drawn and 24 time zones created. (Today in Science History)
2 November 1493...Explorer Christopher Columbus first sighted the island of Dominica in the Caribbean Sea.