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Dead zone (ecology)

Dead zone (ecology)
Red circles show the location and size of many dead zones. Black dots show dead zones of unknown size.The size and number of marine dead zones—areas where the deep water is so low in dissolved oxygen that sea creatures can't survive—have grown explosively in the past half-century. – NASA Earth Observatory[1] In March 2004, when the recently established UN Environment Programme published its first Global Environment Outlook Year Book (GEO Year Book 2003), it reported 146 dead zones in the world's oceans where marine life could not be supported due to depleted oxygen levels. Some of these were as small as a square kilometre (0.4 mi²), but the largest dead zone covered 70,000 square kilometres (27,000 mi²). A 2008 study counted 405 dead zones worldwide.[3][4] Climate has a significant impact on the growth and decline of ecological dead zones. Internationally celebrated limnologist Dr. Additionally, natural oceanographic phenomena can cause deoxygenation of parts of the water column. Related:  Crayfish & ShrimpOcean Dead Zones

Redclaw Hatchery & Farm - AquaVerde - Atherton Tablelands, Queensland, Australia - FOR AQUAPONICS | AquaVerde Redclaw Hatchery & Farm We have received a lot of inquiries about using redclaw in aquaponics systems. It’s not something we know much about, so to get some experience we decided to use our waste water from our “out of season spawning tanks” (RAS system) to grow our veggies. (We’ll let you know how we went.) What has become clear is that craylings are not the best for aquaponics. Craylings thrive in mature earth pond where they have access to natural live foods. To keep them in an artificial environment is challenging until they grow a bit. Advanced Juveniles (80mm – 120mm) - not for export Minimum order: 75 AJ’s @ $1.50 each + transport Redclaw are quite hardy and easy to keep. Oh and don’t mix predatory fish with redclaw!

SCIENCE FOCUS: DEAD ZONES — GES DISC: Goddard Earth Sciences, Data & Information Services Center Info Home page for information about educational resources and outreach activities of the NASA Goddard Earth Sciences Data and Information Services Center The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) provides a broad variety of data to scientists around the world. The data and tools at the GES DISC also provide multiple ways in which teachers and students can gain insight into the interconnected spheres of Earth’s environment – the atmosphere, hydrosphere, cryosphere, biosphere, and geosphere. Furthermore, the GES DISC and its partners have created different informational sources conveying the vital importance of data from NASA Earth observing satellites for the understanding of the Earth system and to investigate and prognosticate the influence of humankind on Earth’s environment, weather, and climate. Data for Education GES DIRECTS (GES DISC Resources for Education & Career Training for Scientists) – in preparation At the GES DISC: Collaborations:

Environmental impact of aviation The environmental impact of aviation occurs because aircraft engines emit noise, and particulates and gases which contribute to climate change[1][2] and global dimming.[3] Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines, the rapid growth of air travel in recent years contributes to an increase in total pollution attributable to aviation. In the European Union, greenhouse gas emissions from aviation increased by 87% between 1990 and 2006.[4] There is an ongoing debate about possible taxation of air travel and the inclusion of aviation in an emissions trading scheme, with a view to ensuring that the total external costs of aviation are taken into account.[5] Climate change[edit] Radiative forcings from aviation emissions (gases and aerosols) in 1992 as estimated by the IPCC Mechanisms and Cumulative Effects of aviation on Climate[edit] Carbon dioxide (CO2) Oxides of nitrogen (NOx) Water vapor (H2O) Particulates

Hypoventilation Causes[edit] It can be caused by medical conditions, such as stroke affecting the brainstem, by holding one's breath, like during hypoventilation training,[2] or by drugs, typically when taken in overdose. Hypocapnia stimulates hypoventilation. Hypoventilation may also occur in chronic mountain sickness to conserve energy.[3] Effects[edit] As a side effect of medicines or recreational drugs, hypoventilation may become potentially life-threatening. Treatment[edit] Respiratory stimulants such as nikethamide were traditionally used to counteract respiratory depression from CNS depressant overdose, but were of only limited effectiveness. If the respiratory depression is from opioid overdose, then the overdose itself is usually treated with an inverse agonist, most likely naloxone, which will itself almost instantaneously stop the respiratory depression if caused by an opioid (and also, depending on the dose, plunge the patient into precipitated withdrawal). Associated conditions[edit]

Shrimp Hatchery Design, Operation and Management Basically, there are two hatchery systems being adopted. The large-tank hatchery which was developed in Japan is still the popular system applied in many Asian countries such as Taiwan, Thailand, Philippines and Indonesia. The small tank hatchery which originated from Galveston USA, has been applied in the Philippines and to same extent in Malaysia and Thailand. Recently a modification of the above systems has been developed which combined the beneficial characteristics of both systems taking into consideration the limitation of spawner supply. There are three determinants in designing a hatchery viz: target species, production target and level of financial inputs. Production target can be determined based on a market demand and financial input. Hatchery design is aimed at achieving the production target which determines the size of the hatchery. Example 1. Production target: 10 million post larvae (PL25) Example 2. Production rate in larval nursing tank: 3,000 PL25/ton or Table 1.

OVERFISHING Oil sludge Oil sludge or black sludge is a solid or gel in motor oil caused by the oil gelling or solidifying, usually at temperatures lower than 100 degrees Celsius. Oil sludge can be a major contributor to internal combustion engine problems, and can require the engine to be replaced, if the damage is severe. Sludge is usually caused by a poorly designed or defective crankcase ventilation system, low engine operating temperatures or the presence of water in the oil, and can accumulate with use. Ways to minimize sludge production and accumulation includes performing frequent oil changes, performing mechanized engine flushing, or de-sludging, using synthetic oil,[1] and following the manufacturer's engine maintenance routine. Toyota, VW, Audi and some Saab engines are known for oil sludge. References[edit] External links[edit]; a technical article about oil sludge, with photos.

Anoxia The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: Stick-Fins Red Claw Farm, Elkton, Fla. Stick-Fins Fish Farm Raising Red Claw freshwater crayfish for a few years now, Michael Robinson has said this is an excellent aquacuture species. His production facility near Elkton, in north Florida, started with only 50 juvenile red claws, is now the largest commercial producer of red claw freshwater lobsters in Florida ...almost doubling in size every year. Here is a young red claw breeder, full of eggs (berried). Here is an example of the juveniles available from this farm. As you can see above, Michael used an inexpensive but very efficient method for his Red Claw production. 8 foot diameter by 18 inch wading pools (from Wal-Mart, appx. $10.00 ea., off season), reinforced with 18" sections of aluminum soffit, for the tanks. AUSTRALIAN RED CLAW PRICES from Stick-Fins PLEASE E-MAIL FOR NEW PRICES! Shipping charges will be determined from customers zip code. Business Hours of Operation and Contact Information: We are open from 8:00 AM EST to 5:00 PM EST Monday through Friday.

Ocean Color Image Archive Page NOTE: All SeaWiFS images presented here are for research and educational use only. All commercial use of SeaWiFS data must be coordinated with GeoEye Category: All Gallery Images This SeaWiFs image provides a view of a Dust storm over the Red Sea. Northwest African Dust Storm A massive dust storm erupted off the northwestern coast of Africa over this past weekend and seemd to be at its maximum intensity on Sunday, 2 March 2003 as seen in this SeaWiFS true color image. Phytoplankton Bloom in the Barents Sea A break in the clouds over the Barents Sea on August 1, 2007 revealed a large, dense phytoplankton bloom to the orbiting MODIS aboard the Terra satellite. Click on the above image for a larger view of the region. Dust from northern Africa often blows across the Mediterranean Sea as was hapenning again on August 19th, 2004 when the above image was collected. Probably the most dominant oceanographic feature of the western North Atlantic Ocean is the Gulf Stream. Prince Edward Islands Plume

Water Water in three states: liquid, solid (ice), and gas (invisible water vapor in the air). Clouds are accumulations of water droplets, condensed from vapor-saturated air. Video demonstrating states of water present in domestic life. Water is a chemical compound with the chemical formula H 2O. A water molecule contains one oxygen and two hydrogen atoms that are connected by covalent bonds. Water is a liquid at standard ambient temperature and pressure, but it often co-exists on Earth with its solid state, ice, and gaseous state, steam (water vapor). Safe drinking water is essential to humans and other lifeforms even though it provides no calories or organic nutrients. Chemical and physical properties Impact from a water drop causes an upward "rebound" jet surrounded by circular capillary waves. Water is the chemical substance with chemical formula H 2O: one molecule of water has two hydrogen atoms covalently bonded to a single oxygen atom. The major chemical and physical properties of water are:

Asphyxiant gas An asphyxiant gas is a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathing air. Breathing of oxygen-depleted air can lead to death by asphyxiation (suffocation). Because asphyxiant gases are relatively inert and odorless, their presence in high concentration may not be noticed, except in the case of carbon dioxide (hypercapnia). Toxic gases, by contrast, cause death by other mechanisms, such as competing with oxygen on the cellular level (e.g., carbon monoxide) or directly damaging the respiratory system (e.g., phosgene). Notable examples of asphyxiant gases are nitrogen, argon, and helium. Asphyxia hazard[edit] Asphyxiant gases in the breathing air are normally not hazardous. Risk management[edit] The risk of breathing asphyxiant gases is frequently underestimated leading to fatalities, typically from breathing helium in domestic circumstances and nitrogen in industrial environments.[13] United States[edit] Odorized gas[edit]

Sea Shepherd International Effects of the automobile on societies Urban land use is often dominated by automobiles. Pictured: São Paulo, Brazil. World map of automobiles per 1000 people. Over the course of the 20th century, the automobile rapidly developed from an expensive toy for the rich into the de facto standard for passenger transport in most developed countries.[1] In developing countries, the effects of the automobile have lagged, but are emulating the impacts of developed nations. The development of the automobile built upon the transport revolution started by railways, and like the railways, introduced sweeping changes in employment patterns, social interactions, infrastructure and goods distribution. The effects of the automobile on everyday life have been a subject of controversy. History[edit] When the motor age arrived at the beginning of the 20th century in western countries, many intellectuals started to oppose to the increase of motor-vehicles on roads. W.S. Access and convenience[edit] External costs[edit] Economic changes[edit]