DATASTREME OCEAN WEEK TEN: 4-8 April 2011

Ocean in the News:

• Eye on the Tropics ---
During the last week:
In the western North Pacific Ocean basin, Tropical Depression 1 formed this past weekend over the waters of the South China Sea off the coast of southern Viet Nam. As of Monday (local time), this tropical depression was moving to the south-southwest.
In the South Pacific Ocean basin, Tropical Cyclone Bune continued to travel to the south-southeast well to the north of New Zealand at the start of last week. During the previous weekend, this cyclone had become a weak category 1 tropical cyclone on the Saffir-Simpson Scale. However, this tropical cyclone weakened to a tropical storm early in the week before it lost its tropical characteristics and became an extratropical (midlatitude) low-pressure system. Satellite images and additional information on Tropical Cyclone Bune can be obtained from the NASA Hurricane Page.
In the South Indian Ocean basin, Tropical Cyclone 20 formed over the waters offshore of northwestern Australia over this past weekend. As of Monday (local time), this tropical cyclone was traveling to the west-southwest.
• Economic assessment teams to be deployed to Northeastern fishing ports --
Early last week, the US Department of Commerce announces that it will deploy economic development assessment teams during April to Portland, ME; Seabrook, NH; New Bedford, MA; Gloucester, MA; Point Judith, RI and Montauk, NY to conduct meetings with local leaders in an attempt to identify the economic development challenges and opportunities in these fishing ports. [US Department of Commerce]
• Use of new fishing hooks will be required for Gulf fishers --
NOAA's Fisheries Service announced that as of early May 2011 it will require commercial fishermen who fish for yellowfin tuna, swordfish and other species with longlines in the Gulf of Mexico to use a new type of hook designed to reduce the incidental catch of the overfished Atlantic bluefin tuna. [NOAA News]
• Salinity monitoring satellite arrives at launch site --
Early last week, the instrument designed to measure ocean surface salinity from the Aquarius/SAC-D spacecraft arrived at Vandenberg AFB in California, the launch site for this mission scheduled for launch in June. The Aquarius instrument on the spacecraft represents collaboration between NASA and Argentina's space agency, with participation from Brazil, Canada, France and Italy. In addition to measuring ocean surface salinity, the mission should help provide information on ocean circulation, the global balance of freshwater and climate. [NASA JPL]
• Salinity differences used to generate electricity --
Researchers from Stanford University have developed an electric battery that utilizes the difference in salinity between freshwater and seawater to generate electricity. These researchers calculate that roughly 13 percent of the world's current energy consumption could be supplied from their batteries if all the world's rivers were utilized. [Stanford University News]
• Heat transport processes to Greenland glaciers studied --
A research team led by a Woods Hole Oceanographic Institution oceanographer has found that ocean circulation plays an important role in transporting heat to Greenland glaciers, which have been rapidly loosing ice mass through melting during the last decade. They base their findings on measured heat fluxes they made in a fjord at the base of a Greenland glacier [Woods Hole Oceanographic Institution]
• Canadian salmon populations likely to survive climate change --
A new study conducted by University of British Columbia scientists indicates that some populations of Fraser River sockeye salmon are sufficiently adapted to their environment that they will be less affected by further environmental changes caused by climate change than some other populations that could disappear. [University of British Columbia]
• Studying the hunting habits of killer whales in Antarctic waters --
Based upon observations of whales off the western Antarctic Peninsula, scientists from the NOAA Fisheries Service's Southwest Fisheries Science Center have found that killer whales in Antarctic waters appear to favor Weddell seals over all other available food sources. [EurekAlert!]
• Antarctic marine ecosystems affected by human impacts --
A team of scientists from the United Kingdom's University of Southampton and the United States has warned that the marine ecosystems of the Southern Ocean surrounding Antarctica are under threat from human activity due to the introduction of alien species, pollution, overfishing, and other human activities. [National Oceanography Centre]
• Biodiversity maps made of Australian sea-shelf --
Marine scientists from five research agencies in Australia including the Commonwealth Scientific and Industrial Research Organisation (CSIRO) have produced a high resolution map of marine life on Australia's continental shelf from data they compiled over three years. [CSIRO]
• Warm ocean water responsible for cold winters in North America and Asia --
Researchers at the California Institute of Technology claim that warm ocean waters off the eastern coasts of North America and Asia have been responsible for the unseasonably cold winters experienced across northeastern North America and northeastern Asia. At the same time, above average temperatures were reported across northwestern sections of Europe and North America. They attribute this temperature pattern to the development of a persistent wavelike pattern in the atmospheric circulation caused by the oceanic heating of the atmosphere off the eastern coasts of the continents. [California Institute of Technology]
• Age of deep-sea black corals in Gulf validated --
Scientists from the US Geological Survey's Pacific Coastal and Marine Science Center and other federal agencies have dated the age of deep sea coral found in the Gulf of Mexico to be approximately 2000 years old. The scientists retrieved the samples using a manned submersible. [USGS Newsroom]
• 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]
• Global and US Hazards/Climate Extremes --
A review and analysis of the global impacts of various weather-related events, to include drought, floods and storms during the current month. [NCDC]
• Earthweek --
Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Solving the Mystery of Seamount Ecosystems

The United States Commission on Ocean Policy reports that less than 5% of the ocean floor has been explored. This is beginning to change as scientists and engineers develop and apply new technologies to investigate deep ocean waters and the sea bottom (refer to Chapter 13 in your DataStreme Ocean textbook). Consider, for example, the effort to obtain a better understanding of seamount ecosystems.

A seamount is a submarine mountain of volcanic origin (now extinct) that rises more than 1000 m (3300 ft) above the ocean floor. Usually a seamount summit is 1000 to 2000 m (3300 to 6600 ft) below sea level. They occur as isolated peaks, chains (e.g., Emperor Seamounts in the North Pacific; New England chain in the North Atlantic), or clusters. The term "seamount" was first applied in 1936 to the Davidson Seamount located off the coast of Southern California. Scientists estimate that perhaps 30,000 dot the ocean floor with as many as two-thirds located on the Pacific Ocean bottom. However, fewer than one thousand seamounts have been named and only a handful of seamounts has received detailed scientific study.

In recent years, discovery of unique life forms on seamounts has spurred scientific interest in seamount ecosystems. Many nations, including the United States, Australia, and New Zealand, are supporting scientific cruises to observe and collect specimens from seamount ecosystems. Seamount ecosystems are unusually productive and are home to unique species. Some seamount surveys have found that certain seamount species are endemic, that is, they live on only one seamount or a few nearby peaks. For example, up to one-third of all species living on some seamounts off New Caledonia are endemic while up to half of the invertebrates and fish on the Nazca seamount off Chile are endemic. In the northeast Pacific, large-scale eddies may transport larval fish from coastal environments to isolated seamounts located out at sea. Furthermore, some scientists argue that seamounts may function as stepping stones that allow for migration of species over lengthy periods--perhaps over millions of years. In addition, some seamounts may serve as aids to navigation for fish that migrate over long distances. For example, hammerhead sharks may use the magnetic field surrounding seamounts to find their way.

The recent effort to survey and explore seamount ecosystems has reached new urgency with the realization of the devastating impact of commercial fish trawlers on those ecosystems. In some cases, trawling has striped off most marine life (e.g., coral gardens) from the surface of seamounts leaving behind mostly bare rock. Typically, trawled seamounts have only half the biomass and considerably fewer species than undisturbed seamounts. Scientists anticipate that a better understanding of seamount ecosystems will help make the case for their conservation and inform the most effective strategies for their protection. Australia is one of the first nations to protect seamount ecosystems, establishing the Tasmanian Seamount Marine Reserve in 1999. The reserve covers 370 square km (140 square mi) and includes more than a dozen seamounts.

Concept of the Week: Questions

1. Seamounts are extinct submarine volcanoes that occur primarily in the [(Atlantic) (Pacific)(Southern)] Ocean.
2. Commercial fish trawling has [(little if any)(a devastating)] impact on seamount ecosystems.

Historical Events:

• 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)
• 8-10 April 1958...A global 48-hr precipitation record was established at Aurere, La Reunion Island, when 97.1 in. of rain from a tropical cyclone fell on the Indian Ocean island. (The Weather Doctor)
• 8-14 April 1984...Intense Tropical Cyclone Kaimsy crossed and re-crossed the northern portion of Madagascar. Winds exceeding 112 mph destroyed 80 percent of Antseranana and Mahajanga. Rainfall from this system totaled 27.99 in. Eighty-two people were killed and 100,000 were made homeless. Damage was greater than 150 million US dollars. (Accord's Weather Guide Calendar) (The Weather Doctor)
• 9 April 1770...The English explorer Captain James Cook discovered Botany Bay on the Australian continent.
• 10 April 1877...The first of two great coastal storms struck the Virginia and North Carolina coasts. The Oregon Inlet was widened by three-quarters of a mile. The "entire topography of country is materially altered," according to a description of the altering of sand dunes at Cape Hatteras, NC. (Intellicast)
• 10 April 1998...Northeast winds at 40 mph on the 9^th and 10^th combined with high levels of Lake Erie produced waves to 14 ft along the lakeshore in Ottawa and Sandusky Counties in Ohio. Much damage resulted, along with the destruction of 10 houses. Bulldozers were needed to clear the debris from roads. Downtown Port Clinton streets were flooded. (Accord's Weather Guide Calendar)

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Prepared by AMS DS Ocean Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2011 The American Meteorological Society.