Time filter

Source Type

North Bethesda, MD, United States

Moore S.E.,National Oceanic and Atmospheric Administration | Reeves R.R.,Okapi Wildlife Associates | Southall B.L.,Safety and Environmental Associates | Ragen T.J.,Marine Mammal Commission | Clark C.W.,Cornell University

The recent loss of Arctic sea ice provides humans unprecedented access to the region. Marine mammals rely on sound as a primary sensory modality, and the noise associated with increasing human activities offshore can interfere with vital life functions. Many coastal communities rely on marine mammals for food and cultural identity, and subsistence hunters have expressed strong concerns that underwater sound from human activities negatively affects both the animals and hunting success. Federal regulations require scientists and oil and gas operators to acquire incidental harassment authorizations for activities that may disturb marine mammals. Currently, authorization requests are focused on the impacts of sound from activities considered in isolation of one another, and this precludes any possibility of a meaningful analysis of the cumulative impacts from multiple sources. We propose a new assessment framework that is based on the acoustic habitats that constitute the aggregate sound field from multiple sources, compiled at spatial and temporal scales consistent with the ecology of Arctic marine mammals. © 2012 Hinterthuer. ISSN. Source

Laist D.W.,Marine Mammal Commission | Taylor C.,Sea to Shore Alliance | Reynolds III J.E.,Mote Marine Laboratory

To survive cold winter periods most, if not all, Florida manatees rely on warm-water refuges in the southern two-thirds of the Florida peninsula. Most refuges are either warm-water discharges from power plant and natural springs, or passive thermal basins that temporarily trap relatively warm water for a week or more. Strong fidelity to one or more refuges has created four relatively discrete Florida manatee subpopulations. Using statewide winter counts of manatees from 1999 to 2011, we provide the first attempt to quantify the proportion of animals using the three principal refuge types (power plants, springs, and passive thermal basins) statewide and for each subpopulation. Statewide across all years, 48.5% of all manatees were counted at power plant outfalls, 17.5% at natural springs, and 34.9 % at passive thermal basins or sites with no known warm-water features. Atlantic Coast and Southwest Florida subpopulations comprised 82.2% of all manatees counted (45.6% and 36.6%, respectively) with each subpopulation relying principally on power plants (66.6% and 47.4%, respectively). The upper St. Johns River and Northwest Florida subpopulations comprised 17.8% of all manatees counted with almost all animals relying entirely on springs (99.2% and 88.6% of those subpopulations, respectively). A record high count of 5,076 manatees in January 2010 revealed minimum sizes for the four subpopulations of: 230 manatees in the upper St. Johns River; 2,548 on the Atlantic Coast; 645 in Northwest Florida; and 1,774 in Southwest Florida. Based on a comparison of carcass recovery locations for 713 manatees killed by cold stress between 1999 and 2011 and the distribution of known refuges, it appears that springs offer manatees the best protection against cold stress. Long-term survival of Florida manatees will require improved efforts to enhance and protect manatee access to and use of warm-water springs as power plant outfalls are shut down. Source

Crawled News Article
Site: http://www.techtimes.com/rss/sections/science.xml

The elusive Omura's whale was caught on video in 2015 for the first time. Now, scientists found the largest population of this rare whale species in Madagascar. A research team was led by New England Aquarium's Dr. Salvatore Cerchio. The scientists documented around 80 Omura's whales off the coast in Madagascar last November. To date, the November report alone doubled the entire number of Omura's Whale sightings in its whole research history. This population included five pairs of mothers and calves. The Madagascar population also recorded some Omura's whales that were seen for the first time. This suggested the possibility of a larger population residing near the island nation. When Cerchio and his team posted the first video footage of the rare 38-foot tropical whales, the discovery made global headlines in early November. When the team returned to Madagascar, they discovered exceptional numbers of euphasiids (tiny shrimps) in the waters of the same area. This suggested that there could be a large population of whales in the vicinity and they were right. The November sighting enabled the research team to observe the Omura's whales' feeding behavior as well as that of the mother-calf pairs. They were also able to analyze the distinct but erratic marks and colors on the species' heads. Cerchio mentioned two major highlights from his latest visit. First, they were able to see their first mother-calf pair. The mother gave the researchers a chance to take an underwater video of the feeding behavior. "The mom was feeding at the surface, making several rolling lunges in which her pectoral fin and fluke came out of the water, while the calf meandered around nearby," wrote Cerchio on the New England Aquarium blog. The second highlight was when they recognized a familiar whale which was observed during their earlier visit. "Upon return to base that night, a check of photos verified that this was in fact a female that we first photographed in 2012 within an aggregation of four whales, and then in 2013 with a calf, and now in 2015 again without a calf," wrote Cerchio. The two-week worth of acoustic data included condensed choruses of the whales' songs. This new data can lead to new information about these rare and elusive tropical whales. For over 30 years, Cerchio has been studying free-range cetacean populations around the world. He is currently New England Aquarium's visiting scientist. The team is hoping to return in May for further research. Cerchio's research was funded by the U.S. Marine Mammal Commission.

Wiliams A.,WHOI | Simmons S.,Marine Mammal Commission | Chavez F.,Moss Landing Marine Laboratories | Houtman B.,National Science Foundation
MTS/IEEE OCEANS 2015 - Genova: Discovering Sustainable Ocean Energy for a New World

A five-year National Science Foundation-funded Research Coordination Network (RCN), the 'OceanObs' RCN is currently in its third year. The RCN continues to focus on key issues in both ocean observations and community outreach. A working group has addressed recommendations for improvements in the joint use of in situ and remote sensing to essential information; considering, as a use case, observation of coastal waters. The RCN supported a task team to identify core variables for ocean biology and a working group is examining the maturity of sensors for ocean biology observations. In addition, a monthly webinar, 'Blue Marvel - Ocean Mysteries' focuses on Outreach. The objective of these diverse activities is to examine alternatives and recommendations to better support the long-term sustainability of ocean observations. © 2015 IEEE. Source

Hooker S.K.,University of St. Andrews | Fahlman A.,Texas A&M University-Corpus Christi | Moore M.J.,Woods Hole Oceanographic Institution | Aguilar de Soto N.,University of La Laguna | And 25 more authors.
Proceedings of the Royal Society B: Biological Sciences

Decompression sickness (DCS; 'the bends') is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N 2) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N 2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N 2 loading to management of the N 2 load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years. © 2011 The Royal Society. Source

Discover hidden collaborations