Weekly Ocean News

Weekly Ocean News

DATASTREME OCEAN WEEK NINE: 31 March-4 April 2014

NEWS UPDATE

Chilean earthquake produces local tsunami --A magnitude 8.2 earthquake struck off the coast of Chile at 1:47 PM Hawaiian Standard Time on 1 April. Landslides and structural damage were reported with more evaluation to be done by daylight. A tsunami caused 6 to 7 foot waves along the Chilean coast. A tsunami advisory is in place for the Pacific region. [CNN]

ITEMS OF INTEREST

Asteroids, climate change and mass extinctions -- You are invited to read this week's Supplemental Information...In Greater Depth that describes how geoscientists have gathered evidence of five major mass extinctions over the last 550 million years from fossil records. These records also help in reconstructing past climates and help in the understanding of climate change.

Ocean in the News:

Eye on the tropics --- During the last week two major tropical cyclones traversed the waters of the South Indian Ocean in the Southern Hemisphere.
Cyclone Gillian, which had its origins to the north of Australia in the western South Pacific basin earlier in the month, strengthened to become a major category 5 cyclone (on the Saffir-Simpson Scale) at the start of last week (local time) as it traveled southward well to the northwest of Australia. This "super" cyclone weakened to a tropical storm and dissipated by midweek approximately 700 miles west of Learmonth, Australia. Consult the NASA Hurricane Page for additional information and satellite imagery on Tropical Cyclone Gillian.
Near the end of last week, Tropical Cyclone Hellen intensified from a tropical storm that formed over the waters of the Mozambique Channel in the western sections of the South Indian basin. This cyclone traveled to the southeast toward the northwestern coast of Madagascar. Over this past weekend, Cyclone Hellen intensified to become a category 4 tropical cyclone. Forecasts indicate that Hellen could make a brief landfall on the coast of Madagascar by late Monday of this week before turning toward the southwest.
Examining white shark activity in California's Gulf of the Farallones --NOAA scientists are examining potential disturbances to the health of white sharks in the waters of California's Gulf of the Farallones National Marine Sanctuary over the next five years that could occur because of research and tourism activities in this national marine sanctuary off the Golden Gate. The public is invited to review and comment through late April 2014 on the draft programmatic environmental assessment evaluating a range of potential white shark research techniques that might be used in the sanctuary. [NOAA News]
Developmental abnormalities in large marine fish attributed to crude oil -- A study conducted by NOAA scientists and their colleagues in academia report that crude oil that spilled into the waters of the Gulf of Mexico following the 2010 Deepwater Horizon disaster appears to be responsible for causing severe defects in the developing hearts of Atlantic bluefin and yellowfin tunas, large marine fish that spawned in oiled offshore habitats in the northern Gulf of Mexico. The chemicals in the crude oil appear to slow the heartbeat or cause an uncoordinated heart rhythm, leading to heart failure. [NOAA News]
First images obtained from new precipitation-sensing satellite -- NASA recently released the first images generated from data collected by the new NASA-JAXA Global Precipitation Measurement (GPM) Core Observatory satellite that was launched as a joint effort between NASA and the Japan Aerospace Exploration Agency (JAXA). One of the first images of the precipitation was made by the GPM Microwave Image of an extratropical cyclone (midlatitude storm) that was moving across the waters of the North Pacific east of Japan's Honshu Island. This instrument has 13 channels that are sensitive to various precipitation types across essentially the full range of precipitation. The other instrument is the JAXA's Dual-frequency Precipitation Radar (DPR) that produced a three-dimensional cross-section of the storm. [NASA]
First federal ocean acidification strategic research plan released -- During the last week the Interagency Working Group on Ocean Acidification that included scientists from NOAA, the National Science Foundation, NASA, the Bureau of Ocean Energy Management, the US Department of Agriculture, the US Department of State, the US Environmental Protection Agency, the US Fish and Wildlife Service, the US Geological Survey and the US Navy released the first federal strategic plan designed to guide research on ocean acidification. This plan should guide multi-disciplinary research and environmental monitoring on oceanic acidification and its impacts on marine ecosystems. [NOAA Office of Oceanic and Atmospheric Research News]
Carbon dioxide levels in tropical Pacific Ocean increasing at rapid rate -- Scientists at the NOAA Joint Institute for the Study of the Atmosphere and Ocean at the University of Washington and colleagues have discovered the amount of carbon dioxide in tropical waters of the Pacific Ocean have increased at a rate as much as 65 percent faster than atmospheric carbon dioxide levels since 1998. This increase in the oceanic carbon dioxide, which has been faster than expected, is also reflected in the rapid rise in ocean acidity. [NOAA Office of Oceanic and Atmospheric Research News]
Atmospheric carbon dioxide levels reach 400 ppm two months earlier than in 2013 -- Scientists at NOAA's Mauna Loa Observatory on the Big Island of Hawaii recently reported that the atmospheric carbon dioxide levels exceeded 400 parts per million (ppm) by volume during a five-day span during mid March 2014, which was nearly two months earlier than its first ever occurrence in 2013. The 400-ppm level has been considered as a milestone in the upward trend in the atmospheric carbon dioxide levels monitored at this Observatory since 1957. A seasonal cycle is also detected in the concentration of this gas, as a maximum occurs in northern spring before the green-up process occurs across the Northern Hemisphere. [NOAA Office of Oceanic and Atmospheric Research News]
Forecasting summertime seasonal Arctic ice extent remains difficult -- Scientists at the National Snow and Ice Data Center (NSIDC), the University College London, the University of New Hampshire and the University of Washington have found that forecasts of summer Arctic sea ice extent are quite accurate when sea ice conditions are close to the long-term downward trend in summer ice, but their forecasts are not so accurate when sea ice conditions are unusually higher or lower compared to this trend. They base their analysis on 300 summer Arctic sea ice forecasts made between 2008 and 2013. Forecasts made in 2012 and 2013 were quite susceptible. Since satellite surveillance began in 1979, the September sea ice, when the seasonal minimum occurs, has decreased by 13.7 percent by decade. [National Snow and Ice Data Center Press Room]
New model capable of providing street-level storm tide predictions -- A research team from The College of William & Mary's Virginia Institute of Marine Science has develop a new high-resolution computer model that can predict a hurricane's storm tide at the level of individual neighborhoods and streets to a much finer scale than current operational methods. This model has been tested through simulations of the historic storm surge in the New York City metropolitan area associated with the land-falling Hurricane Sandy in October 2012. [Virginia Institute of Marine Science]
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, drought, floods, marine weather, tsunamis, rip currents, Harmful Algal Blooms (HABs) and coral bleaching. [NOAAWatch]
Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Controlling Nutrient Input into Chesapeake Bay

Chesapeake Bay is the nation's largest estuary; it is more than 300 km (185 mi) long, 65 km (40 mi) at its broadest, and averages about 20 m (66 ft) deep. The estuary was formed by the post-glacial rise in sea level that flooded the valley of the ancient Susquehanna River. The Bay receives about half its water from the Atlantic Ocean and the other half from the more than 150 rivers and streams draining a 166,000 square kilometer land area encompassing parts of New York, Pennsylvania, West Virginia, Delaware, Maryland, Virginia, and the District of Columbia. Major rivers that empty into Chesapeake Bay include the Potomac, Susquehanna, York, and James.

As described in more detail on pages 227-229 of your DataStreme Ocean textbook, an estuary is a complex and highly productive ecosystem where seawater and freshwater runoff meet and mix to some degree. In Chesapeake Bay, more-dense seawater creeps northward along the bottom of the estuary, moving under the less-dense fresh water flowing in the opposite direction. This circulation combined with wind-driven and tidal water motions causes salinity to decrease upstream in the Bay, from values typical of the open ocean at its mouth to freshwater values at its northern margin.

As in all ecosystems, organisms living in estuaries depend on one another and their physical environment for food energy and habitat. Phytoplankton and submerged aquatic vegetation (e.g., marsh grass) are the primary producers (autotrophs) in estuarine food chains. Chesapeake Bay consumers (heterotrophs) include zooplankton, finfish, shellfish, birds, and humans.

Human activity has greatly modified Chesapeake Bay with consequences for the functioning of the ecosystem. Much of the original forests that covered its drainage basin were cleared and converted to farmland, roads, cities, and suburban developments. These modifications accelerated the influx of nutrients (i.e., compounds of phosphorus and nitrogen), sediment, pesticides, and other pollutants into the Bay. More nutrients spur growth of algal populations and when these organisms die (in mid-summer), their remains sink to the bottom. Decomposition of their remains reduces dissolved oxygen levels in the Chesapeake's bottom water. More sediment increases the turbidity of the water, reducing sunlight penetration for photosynthesis. Presently Chesapeake Bay is on the Federal list of "impaired waters" and in need of pollution abatement and remediation. States in the drainage basin have agreed to work together to clean up the Bay but there are significant obstacles including cost.

One casualty of human modification of the Chesapeake Bay ecosystem was marsh grass-reduced by 90% from historical levels. Marsh grass anchors sediment and dampens wave action thereby controlling shoreline erosion and turbidity. Marsh grass is a food source for many organisms including waterfowl and small mammals and serves as a primary nursery for crabs and many species of fish. Reduction of this habitat along with over-fishing has been implicated in the decline of populations of blue crabs, a mainstay of the Bay fishery for more than a century. Over the past decade, the number of adult female blue crabs plunged by 80%. Without adequate protection by marsh grass, blue crabs are more vulnerable to predation by striped bass (i.e., rockfish). Striped bass turned to blue crabs as a food source when fishing reduced the numbers of menhaden, their preferred food. Menhaden is a marine fish in the herring family and the Bay's top fishery by weight.

Human modification of the Chesapeake Bay drainage basin converted it from an essentially closed system to an open system. In the original climax forests, nutrients primarily cycled within the system with relatively little input to the Bay. Modification of the land for agriculture increased the area of the soil exposed to the elements and runoff from rain and snowmelt accelerated nutrient input into the Bay. In addition to such non-point (area) sources of nutrients are point sources including the effluent of wastewater treatment plants that discharge treated water into rivers and streams that drain into the Bay.

For decades, agriculture has successfully employed various cultivation practices that limit the runoff from cropland (e.g., contour plowing, strip cropping, and retention ponds.) However, less than one-third of the 300-wastewater treatment facilities located in the Chesapeake Bay drainage basin have the technology to remove high levels of nutrients from their effluent. Under current environmental regulations, states are not required to regulate the nutrient content of this discharge. But in late October 2003, the Chesapeake Bay Foundation, a private, not-for-profit environmental advocacy organization called on Virginia, Maryland, Pennsylvania, and the District of Columbia to specify nutrient limits on permits they grant to all wastewater treatment facilities. In support of their recommendations, the Chesapeake Bay Foundation cited the many water quality problems stemming from excessive nutrient load in the Bay waters (e.g., algal blooms, spread of "dead zones.") According to the U. S. EPA, under the federal Clean Water Act, a state can control nitrogen pollution if it determines that environmental harm is taking place. However, the EPA estimates that as much as $4.4 billion would be required to install state-of-the-art nutrient removal technologies at all major plants (those treating more than 500,000 gallons of wastewater per day).

Concept of the Week: Questions

In terms of nutrient cycling, the climax forest that originally occupied the Chesapeake Bay drainage basin was a(n) [(open)(closed)] system.
Excessive input of nutrients into Chesapeake Bay [(spurs the growth of)(has little impact on)] algal populations and [(increases)(reduces)] the concentration of dissolved oxygen in bottom waters.

Historical Events:

31 March 1932...The United States signed the Whaling Convention at Geneva with 21 other countries. (USCG Historian's Office)
31 March 1995...Coast Guard Communication Area Master Station Atlantic sent a final message by Morse code and then signed off, officially ending more than 100 years of telegraph communications. (USCG Historian's Office)
31 March 2000...The water temperature of Lake Erie at Buffalo, NY was 39 degrees Fahrenheit on the last day of March, tying the maximum temperature for the date with that of 1998. Ice was present in 61 of 74 years on the 31^st, but this was third year in a row with open water. (Accord's Weather Guide Calendar)
1 April 1873...The British White Star steamship Atlantic sank off Nova Scotia killing 547 after striking an underwater rock near Meagher's Island while on a voyage from Liverpool, England to New York City. Only 413 people survived. (Wikipedia)
1 April 1946...The Scotch Cap Lighthouse on Unimak Island in Alaska's Aleutian Islands was shaken by two earthquakes in a 27 minute span, then obliterated by a tsunami wave. The entire five-man crew was killed and the lighthouse antenna (105 ft above sea level) was washed away. Some debris was found 115 ft above sea level. The tsunami that propagated across the Pacific Ocean was responsible for more than 165 fatalities and over $26 million in damage. Many of the casualties were on the Hawaiian Islands, especially in Hilo on the Big Island. This tsunami was responsible for the development of the current Pacific Tsunami Warning System. (University of Washington) (Accord's Weather Guide Calendar) (US Coast Guard Historian's Office)
2 April 1513...Spanish explorer Juan Ponce de Leon came ashore on the Florida coast near present-day St. Augustine and claimed the territory for the Spanish crown. He is reported to be the first known European to set foot in Florida. (The History Channel)
2 April 1958...One of the most destructive coastal storms in years battered New England (31 March-3 April). Some beaches between Portland, ME and Cape Cod, MA were eroded by approximately 50 ft. Miles of sea walls and bulkheads were either breached or demolished. Many beachfront cottages in Massachusetts, New Hampshire and Maine were sandblasted. (Accord's Weather Guide Calendar)
2 April 1926...Baden-Baden, a rotor ship invented by Anton Flettner left Hamburg, Germany on a transatlantic crossing, arriving in New York on 29 May 1926. The ship used two 9-ft diameter, 50-ft high cylinders, mounted vertically on the deck at the bow and the stern for propulsion, utilizing the aerodynamic power of the Magnus Effect, which builds air pressure behind a rotating cylinder. (Today in Science History)
3 April 1797...Captain Thomas Truxtun, USN, devised and issued the first known American signal book using numerary system, encompassing 10 numeral pennants, made of combinations of red, white, blue, and yellow bunting, with flags for repeaters. This signal book contained approximately 300 signals. Fog signals were made by gunfire. Night signals were made by lanterns and gunfire. (Naval Historical Center)
4 April 1581...The famous English navigator, Francis Drake, completed his circumnavigation of the world (1577 to 1580) and was knighted by Queen Elizabeth I. (Wikipedia).
6 April 1894...President Grover Cleveland authorized enforcement of the Paris Award concerning the preservation of fur seals in Alaska. (USCG Historian's Office)
6 April 1909...The American explorer, Commander Robert E. Peary, USN, along with assistant Matthew Henson, and four Eskimos reported reaching the geographic North Pole; however, navigational errors may have meant that they were a few miles away from the exact pole. (Naval Historical Center) (The History Channel)
6 April 1913...USRC Seneca, a derelict destroyer (whose mission was to locate and destroy abandoned wrecks that were still afloat and a menace to navigation), inaugurated the Revenue Cutter Service's participation in the International Ice Patrol. (USCG Historian's Office)