DataStreme WES Week Seven: 18-22 October 2004

• Oil spill affecting Indonesian islands -- An oil leak that began over one week ago has developed into an oil spill that has spread across the Java Sea to a chain of Indonesian tourist islands called the Thousand Islands near Jakarta, adversely affecting the tourism and fishing industries. [ENN]
• Keeping Asian carp from the Great Lakes -- Within the next two weeks, the US Army Corps of Engineers will begin building a $9.1 million electric barrier on the Chicago Sanitary and Ship Canal that is intended to keep the invasive Asian carp from entering Lake Michigan from the Mississippi and Illinois river systems. [ENN]
• Gulf fisheries threatened by wetland loss and runoff -- A researcher at Woods Hole Oceanic Institution recently reported that the loss of wetlands and the amount of agricultural runoff could be responsible for the development of a "dead zone" of oxygen-depleted water in the Gulf of Mexico, which would cause a decline in the fisheries. He recommended steps to avert additional expansion of the dead zone that would include wetland restoration and a marked reduction in the use of fertilizers on the Mississippi River watershed. [US Water News Online]
• Ecuadorian glaciers waning -- Scientists from Ecuador and France recently reported that Ecuador's Cotopaxi volcano lost 31 percent of its ice cover from 1976 to 1991 and other Ecuadorian glaciers could disappear in the next two decades, causing a major problem for fresh water supply. [ENN]
• Everglades restoration project to begin -- The state of Florida announced that it intends to start eight projects aimed at restoring the Everglades, to include building reservoirs intended to ease suburban flooding and damage from hurricanes. [ENN]
• Postponement of an Ukrainian canal urged -- The European Union is urging Ukrainian officials to postpone the completion of a 105-mile canal through the Danube Delta in the Ukraine because of environmental concerns [ENN]
• A new pricey fad -- At least one company on the Kona coast of the Big Island of Hawaii has been cashing in on the soaring Japanese demand for bottled water obtained from the bottom of the ocean. The desalinated water that has been extracted from an ocean depth of 2000 feet is marketed as being high-quality, natural and pure and sells for up to $6 for a 1.5-liter bottle. [US Water News Online]
• More insects result from El Niño drought -- Researchers with the Smithsonian Tropical Research Institute recently reported that they associated an explosive increase in the moth population in a dry lowland forest near Panama's Pacific coast with a regional drought resulting from the 1997-98 El Niño event, an anomalous atmospheric and oceanic circulation pattern. The moth outbreak resulted in massive defoliation of trees. [EurekAlert!]
• An improved bleaching agent found in Yellowstone -- A type of bacterium that survives in the waters of the hot springs of Yellowstone National Park could produce an enzyme that would make industrial bleaching cheaper and more environmentally friendly as reported recently by researchers with the Idaho National Engineering and Environmental Laboratory. [EurekAlert!]
• Monitoring hazardous waste sites -- A new underground probing system developed at the Idaho National Engineering and Environmental Laboratory that would track the molecules of hazardous waste in landfills recently won an award as one of the 100 most significant technological achievements of 2004. [EurekAlert!]
• Restoration of Mesopotamian marshlands planned-- Australian consultants are ready to help assess and restore the Mesopotamian marshlands that were drained and burned during the regime of Saddam Hussein in Iraq. [EurekAlert!]
• Water on Mars may have been short-lived -- A geosciences doctoral candidate at Virginia Tech has reported that her analysis of the mineral jarosite by the NASA Mars Rover Opportunity would suggest that liquid water would have probably existed on the Martian surface for a relatively short time span. [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]
• Global Water News Watch -- Other water news sources can be obtained through the SAHRA Project at the University of Arizona [SAHRA Project]
• Earthweek -- Diary of the Planet [earthweek.com] Requires Adobe Acrobat Reader.

Concept of the Week: Dams and Ecological Integrity

Dams disrupt the natural seasonal fluctuations in the flow of rivers and streams with potentially serious consequences for the integrity of aquatic ecosystems. For one, dams interfere with the upstream and downstream migration of fish. Storage of water in reservoirs behind dams reduces the downstream discharge of water, sediment, and nutrients. These and other alterations of fluvial habitats threaten or endanger more than 20% of all freshwater species.

The ecological impact of dams is extensive because these structures affect so much runoff. Worldwide, almost 3000 dams have a reservoir storage capacity exceeding 25 billion gallons--a combined volume of water roughly equivalent to that in Lakes Michigan and Ontario. The more than 70,000 dams in the U.S. can store half of the annual flow of all the nation's rivers and streams.

The continuity of the global water cycle implies that disruption of river and stream flow by dams can also impact marine and lacustrine (lake) ecosystems. In the Pacific Northwest, for example, only about 5% of juvenile salmon survive passage through dams and reservoirs on the Columbia and Snake Rivers. Salmon are anadromous, that is, they spawn in freshwater streams, but spend most of their adult life in the ocean. After hatching, young salmon (smolts) swim downstream to the Pacific Ocean, where they mature and then return to the same streams to spawn. But the 56 major dams in the Columbia River watershed are formidable obstacles to salmon migration. Largely ineffective are fish ladders designed to help the salmon move upstream and other structures that guide them downstream around hydroelectric turbines. (These turbines have been likened to giant food processors for smolt attempting to swim through them.) Furthermore, smolts on their downstream passage are held up in reservoirs where they are exposed to predators, pathogens (disease-producing organisms), and water that is too warm. Atlantic salmon have a similar fate. More than 900 dams on New England and European rivers prevent most Atlantic salmon from reaching their freshwater spawning grounds. Consequently, their population has declined to less than 1% of historical levels.

Traditionally, dam operators regulate stream and river flow for flood control and to supply water for electric power generation and irrigation. But recently, in response to greater awareness of the adverse impacts of dams on aquatic ecosystems, has come a growing interest in operating dams in ways that recreate the river's natural seasonal flow pattern and habitats. For example, this type of management is employed on the Flaming Gorge Dam on the Green River in Utah to protect sensitive habitats for endangered species including chubs and squawfish. The dam operator simulates spring floods of the pre-dam era by releasing a surge of water in May that facilitates fish spawning.

Controlled flooding has been used on the segment of the Colorado River that flows through the Grand Canyon in an attempt to help restore landforms and aquatic habitats downstream from the Glen Canyon Dam. Before the dam first came into operation in 1956, natural floods regularly delivered sediment from the tributaries of the Colorado River. Sand and silt built sandbars and created backwaters that provided habitat for a variety of native plant and fish species such as the humpback chub and razor sucker. The humpback chub, for example, prefers the warmer and murkier waters associated with sandbars. With the dam in full operation, sand and silt was trapped in the reservoir upstream from the dam and the sandbars and backwater habitats were gradually destroyed. The number of humpback chub in the Grand Canyon declined from about 8300 in 1993 to about 2000 today and the species is close to extinction. In an attempt to restore downstream habitats, in March 1996 a huge gusher of water was released from the Glen Canyon Dam and a fresh influx of sediment built new beaches and sandbars. But these landforms and habitats disappeared within a few months. Now the U.S. Bureau of Reclamation is proposing a new flood plan based on lessons learned from the 1996 flood. The plan is to release floodwaters from the Glen Canyon Dam for a shorter period of time (2.5 days instead of the 7-day 1996 flood) and only after a sufficient buildup of sediment so that floodwaters construct sandbars and beaches rather than washing them away.

Concept of the Week: Questions

1. Alteration of aquatic habitats by dams [(is)(is not)] a reason why some fish species become threatened or endangered.
2. Anadromous species of fish spawn in [(the ocean)(freshwater rivers and streams)].

• 18 October 1910...Northeasterly winds as high as 70 mph (from a hurricane moving northward up the Florida peninsula) carried water out of Tampa Bay and the Hillsboro River. The water level lowered to nine feet below mean low water. Forty ships were grounded. (The Weather Channel)
• 19 October 1844...The famous "Lower Great Lakes Storm" hit the Buffalo, NY and Toronto, Ontario area. Barometric pressure at Toronto fell to 977 millibars (28.86 inches of mercury). Southwesterly winds were at hurricane force for five hours, driving lake waters into downtown Buffalo, NY. The storm drowned 200 persons. (David Ludlum)
• 20 October 1999...A flash flood roared down the normally placid Palikea Stream in Hawaii's Haleakala National Park, causing the stream to rise 15 to 20 feet in one minute. Twelve tourists swimming in Palikea's lower pools clung to cliff sides and were eventually rescued. (Accord Weather Calendar)
• 21 October 1938...The Hector Glacier crashes to the valley floor northeast of Lake Louise, Alberta. The valley is buried under a 1.2-mile wide by 2.5-mile long pile of ice rubble. The wind created by the falling avalanche blows down all trees on the opposite side of the valley. (The Weather Doctor)
• 21 October 1996...Portland, ME received 13.32 inches of rain to set a 24-hour maximum precipitation record for the Pine Tree State. (NCDC)
• 21 October 1998...A tropical depression formed over the southwestern Caribbean Sea about 360 miles south of Kingston, Jamaica. It would intensify over the next few days to become Hurricane Mitch, the second deadliest Atlantic hurricane on record, on the 24^th. (The Weather Doctor)
• 22 October 1987...Yakutat, AK surpassed their previous all-time yearly precipitation total of 190 inches. Monthly records were set in June with 17 inches, in September with 70 inches, and in October with more than 40 inches. (Sandra and TI Richard Sanders - 1987)
• 22 October 1988...A "nor'easter" swept across the coast of New England. Winds gusted to 75 mph, and large waves and high tides caused extensive shoreline flooding. Heavy wet snow blanketed much of eastern New York State, with a foot of snow reported in Lewis County. (The National Weather Summary) (Storm Data)
• 23-24 October 1918...The Canadian steamship Princess Sophia carrying miners from the Yukon and Alaska became stranded on Vanderbilt Reef along coastal British Columbia:. A strong northerly gale hampered rescue attempts, and the next day, the ship sank with the loss of the 268 passengers and 75 crewmen on board. (The Weather Doctor)
• 24 October 1785...A four-day rain swelled the Merrimack River in New Hampshire and Massachusetts to the greatest height of record causing extensive damage to bridges and mills. (David Ludlum)
• 24 October 1933...A "high fog" settled over London, England causing "midnight at mid-day" as a temperature inversion forms over the city, trapping fog and smoke beneath it. The sun turned yellow, red and sometimes disappeared. (The Weather Doctor)

Return to DataStreme WES Homepage

URL: DSWES:/news.html
Prepared by AMS WES Central Staff and Edward J. Hopkins, Ph.D., email hopkins@meteor.wisc.edu
© Copyright, 2004, The American Meteorological Society.