How Marine Mammals React to Underwater Sound
Connie Barclay, NOAA Fisheries, (301) 713-2370 x 144
NOAA Fisheries Service is looking at how marine mammals react to underwater sound. Increasing evidence suggests that exposure to intense underwater sound in some settings may cause certain marine mammals to strand and ultimately die. Some of these strandings are associated with mid-frequency active (MFA) military sonar, and most have involved beaked whales; the dominant species is Cuvier's beaked whale (Ziphius cavirostris), but the genus (Mesoplodon) has also been involved. The coincidence between certain atypical mass strandings and active sonar exercises is convincing, but insufficient information is available to assess whether other signals pose a similar risk, and whether other species may also be at risk. Until the causes of these strandings can be identified, and possibly dose- response relationships defined, it will remain difficult to discriminate an actual hazard from random coincidences of human activities and natural strandings.
A multi-phase field research project is underway to conduct Behavioral Response Studies of various underwater sounds to marine mammals (including beaked whales and other odontocetes). The overall goal of the study is to understand the initial steps in the chain of events that lead from sound exposure to atypical mass strandings of beaked whales; and to use that understanding to identify a safe response that can be used to indicate risk.
Why is the Arctic Melting So Fast?
Anatta, NOAA Research, (303) 497-6288
Greenhouse gases alone don't explain the rapid rate of Arctic ice melt. Computer models disagree on how long it will take for sea ice to vanish completely each summer. During April, NOAA's Earth System Research Laboratory will fly an off-duty Hurricane Hunter aircraft out of Fairbanks, Alaska, to observe the Arctic springtime. Scientists will analyze four factors that are poorly understood and may be helping to heat up the region:
- Aerosols (airborne particles) absorb both energy from the sun and infrared radiation from Earth. Fossil fuel and biomass burning are primary sources of heat-absorbing aerosols.
- These same aerosols indirectly affect Arctic climate by changing cloud properties, especially the amount of infrared heat given off by wintertime and springtime clouds.
- Soot, or black carbon, deposited on snow accelerates springtime snowmelt by absorbing light and heat.
- Ozone in the lower Arctic atmosphere acts as a greenhouse gas, directly affecting radiation in the region.
Called ARCPAC (Aerosol, Radiation, and Cloud Processes Affecting Arctic Climate), the airborne mission is part of the International Polar Year 2008 research activities.
NOAA Researchers Use Cold War Era Radiocarbon Traces to Find Fish Ages
Connie Barclay, NOAA Fisheries, (301) 713-2370 x 144
Researchers at NOAA's Alaska Fisheries Science Center are finding trace radiocarbon (C-14) from Cold War nuclear bombs in the ear bones of fish, and turning this artifact of nuclear testing into a timestamp for determining fish ages.
Researchers have used traces of C-14 to confirm the ages of Pacific Ocean perch from the Gulf of Alaska, and have proven the method to be important information for fishery stock assessment and management. Alaska Fisheries Science Center researchers plan to apply the method to other fish species.
During the height of the Cold War in the late 1950's to early '70's, the United States, Russia, and other countries exploded enough above-ground nuclear bombs to raise the amount of C-14 in the atmosphere and in the surface layers of the ocean. C-14 has a half-life of 5,730 years. After the increase from the test bombing, C-14 has been decaying slowly in the environment, giving scientists a benchmark level for each year.
Fish ear bones, called otoliths, grow in 'rings' similar to annual growth rings found in trees. Researchers know the year that the fish was collected, and can count growth rings back to estimate the age of the fish. If the amount of C-14 detected in the first growth ring of the otolith matches up with the expected environmental amount in that year, then the estimated age of the fish is correct.
La Niña's Weather Impacts Are Reaching Peak Strength in the United States
Susan Buchanan, NOAA National Weather Service, (301) 713-0622 x110
The United States is currently experiencing the strongest La Niña system in eight years, and scientists indicate that the system is nearing peak strength. Many of the extreme weather patterns seen this year, such as above-average rains in the Pacific Northwest and drought in the South, can be attributed, in part, to La Niña. Recent research has also shown a connection between La Niña and winter tornadoes.
Forecasters identify La Niña when they find unusually cold ocean temperatures in the eastern equatorial Pacific. La Niña tends to bring wetter than normal conditions across the Pacific Northwest and dryer and warmer than normal conditions across much of the southern tier. The impacts of La Niña at these latitudes are most clearly seen in wintertime. In the continental U.S., during a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest.
NOAA Hurricane Hunter Flies Into Pacific Winter Storms
Jeanne Kouhestani, NOAA Office of Marine and Aviation Operations, (301) 713-7693
In an effort to improve forecasts released 12-72 hours before a Pacific winter storm, NOAA is flying its Florida-based WP-3D "hurricane hunter" aircraft into severe weather originating over the Pacific Ocean. The P-3 is deploying out of a temporary base in Portland, Ore., Feb. 1 to March 15 to collect atmospheric data in severe winter storms that will seriously impact the continental United States.
An addition, a new experiment--the Hydrometeorology Testbest (HMT) "Atmospheric Rivers" project--will be added to the aircraft's mission. HMT will focus observations on low-level jets of high moisture within winter cyclones making landfall on the West Coast. In addition to causing flooding rains in the coastal mountains and playing a critical role in the global water cycle, atmospheric rivers are integral to water resource issues in the semi-arid West, where a majority of snowfall in the higher elevations provides year-round fresh water to the population.
Media are invited to fly on the P-3 out of Portland International Airport. Flights begin around 11 a.m. and end around 7 p.m. PST. Flights, dependent on weather conditions, are scheduled one day in advance. Please contact Lori Bast at 813-828-3310, ext. 3072 (Tampa, Fla.) for flight information and to request a seat on the aircraft.
Fish Kill Study Will Advance HAB Prediction
Ben Sherman, NOAA National Ocean Service, 301-713-3066 ext. 178
Water samples taken during the development of a 2006 harmful algal bloom (HAB) in North Carolina's Neuse River Estuary will help coastal managers predict fish-kills and allay public fears about these events. For the first time, NOAA researchers and colleagues used real-time data from shipboard and fixed automated sampling stations to document conditions surrounding a fish kill caused by the toxic dinoflagellate Karlodinium veneficum. This species is lethal to fish, but harmless to humans.
The real-time data of a K. veneficum event was shown to provide clues that help explained the development and demise of this bloom, and providing managers with an improved understanding of when K. veneficum blooms may occur in the future. The work was completed in collaboration with the University of North Carolina's Institute of Marine Sciences, the Maryland Center for Marine Biotechnology in Baltimore and the North Carolina Department of Environmental Quality and is part of NOAA's ongoing efforts to forecast and manage harmful algal blooms. NOAA currently supports ecological HAB forecasting systems off the Florida and Texas Gulf coasts and is working to develop similar capabilities in New England and Pacific Northwest waters.
NOAA Scientists Study 12,700 Mile Migratory Journey of Leatherback Sea Turtles across the Pacific
Connie Barclay, NOAA Fisheries, (301) 713-2370 x 144
NOAA researchers and their international partners in Indonesia, Papua New Guinea, and the Solomon Islands are using satellite transmitter technology to track the endangered leatherback sea turtle across the Pacific Ocean. Transmitters attached to the carapace of the turtle send signals to satellites providing researchers with information on the animals' geographic location, diving behavior, and sea temperatures.
Recently, a female leatherback sea turtle was tracked for 647 days and 12,744 miles during its journey from a nesting beach of Papua, Indonesia to its foraging area off the Pacific coast of the United States of America. This international collaborative effort allows researchers to learn what migratory routes and foraging habitat are used by these endangered ambassadors of the sea. Understanding sea turtles' movements is critical to understanding what habitat is important for their survival and recovery and ensuring their protection as they pass through multiple nation's territories and international waters.
Leatherback populations face threats from egg harvesting, fishery bycatch, ingestion of debris, direct harvest, and habitat loss. Satellite tracking technology is one tool allowing NOAA researchers to unlock secrets of the incredible journeys of this species, allowing us to better understand where they go, what threats they might face at sea, and what management efforts will be required to ensure this species' survival. The new technology can be used in all the world's oceans and is being used for other sea turtle and non-sea turtle species research.
New Study Shows Extent of Harmful Human Influences on Global Marine Ecosystems
John Leslie, NOAA Satellite and Information Services, 301-713-2087 ext 174
More than 40 percent of the world's oceans are heavily impacted by human activities, including overfishing and pollution, according to a new study appearing in this week's (Feb. 15, 2008) issue of the peer-reviewed journal Science.
Dr. Kenneth Casey, with NOAA's Oceanographic Data Center is a co-author of the study which combined 17 data sets of different human activities - from fishing and fertilizer run-off, to commercial shipping and pollution - and analyzed their effects on marine ecosystems, continental shelves and the deep ocean. He says that human-induced climate changes in sea surface temperatures, UV radiation and ocean acidification are among the most important factors in determining the global impacts.
According to the study, the ecosystems most at threat are: coral reefs, which house more than 25 percent of all marine life and protect against wave erosion; seagrass beds, which help ward off coastal erosion; and mangroves, which are trees and shrubs that grow in coastal habitats.
NOAA Analyzes Impacts of Marine Anti-foulants in Estuaries
Ben Sherman, NOAA National Ocean Service, 301-713-3066, ext. 178
NOAA toxicity assessments of the anti-fouling biocide, Irgarol 1051 in larval and adult grass shrimp (Palaemonetes pugio) showed that Irgarol was more toxic to larvae than adults.
Grass shrimp is an ecologically important species in salt marsh ecosystems, with its populations vital to the function of the coastal food web in much of the U.S. Sublethal effects on several biomarkers were observed only in larvae. The toxicity in both life stages was observed only at concentrations above those that have been reported in the environment. These findings were recently published in the Journal of Environmental Science and Health Part B. Irgarol has been detected worldwide in seawater and these findings will be helpful in assessing the risk to estuaries associated with this emerging contaminant.