The Game Dead

[Consuela Ellett]

At 3,058 square miles, the 2023 hypoxic zone in the Gulf of Mexico is the 7th smallest ever measured in the 37-year record, measured from July 23 to July 28, 2023. Red area denotes 2 milligrams per liter of oxygen or lower, the level which is considered hypoxic, at the bottom of the seafloor. (Bottom panel) Long-term measured size of the hypoxic zone (green bars) measured during the ship surveys since 1985, including the target goal established by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force and the 5-year average measured size (black dashed lines). Graphic credit: Louisiana Universities Marine Consortium

Hypoxic zones can occur naturally, but scientists are concerned about the areas created or enhanced by human activity. There are many physical, chemical, and biological factors that combine to create dead zones, but nutrient pollution is the primary cause of those zones created by humans. Excess nutrients that run off land or are piped as wastewater into rivers and coasts can stimulate an overgrowth of algae, which then sinks and decomposes in the water. The decomposition process consumes oxygen and depletes the supply available to healthy marine life.

Property owners are responsible for removing dead animals on their property. Do not bury dead animals. If you find a dead animal, you can put the animal in a sealed trash bag and place it in the trash. You can also bring the dead animal to ACCT Philly for disposal.

Scientists have determined that the dead zone was about the size of Delaware during the summer of 2018. This is the fourth-smallest dead zone mapped since 1985, likely due to wind patterns that helped mix more oxygen into the water. However, high levels of nutrient runoff continue to flow into the Gulf, meaning that the underlying cause of large recent dead zones remains a serious problem.

In river basins throughout the Mississippi River watershed, TNC staff are working with farmers, university scientists and departments of agriculture to promote more effective and efficient use of fertilizers and reduce the amount of nutrients that enters our rivers from other sources. In many cases better nutrient management also leads to better soil management, which reduces surface runoff and flooding and maintains or enhances agricultural productivity.

West Nile virus is transmitted to birds through the bite of an infected mosquito. Mosquitoes become infected by biting infected birds. Some birds that are predators (such as hawks and owls) or scavengers (such as crows) may become infected after eating sick or dead birds that were already infected with West Nile virus. Some birds that eat infected mosquitoes may also become infected.

Although some infected birds, especially crows and jays, frequently die of infection, most birds survive. Since West Nile virus was discovered in the United States in 1999, the virus has been detected in over 300 species of dead birds.

There is no evidence that a person can get infected from handling live or dead infected birds. However, you should avoid bare-handed contact when handling any dead animal. If you must pick up a dead bird, use gloves or an inverted plastic bag to place the bird in a garbage bag.

West Nile virus is found in all 48 contiguous states (not in Alaska or Hawaii) and the virus circulates in mosquitoes and birds every year. Because West Nile virus is well established, some states and local jurisdictions are no longer collecting dead birds for testing. Instead, they have chosen to shift staff and funding resources away from testing of dead birds to other areas of West Nile virus surveillance and control.

The Dead Sea has attracted visitors from around the Mediterranean Basin for thousands of years. It was one of the world's first health resorts, and it has been the supplier of a wide variety of products, from asphalt for Egyptian mummification to potash for fertilisers. Today, tourists visit the sea on its Israeli, Jordanian and West Bank coastlines.

The English name "Dead Sea" is a calque of the Arabic name, itself a calque of earlier Greek and Latin names[citation needed], in reference to the scarcity of aquatic life caused by the lake's extreme salinity.[12]Historical English names include the Salt Sea,[13] Lake of Sodom[13] from the biblical account of its destruction[14] and Lake Asphaltites[13] from Greek and Latin.

The Dead Sea lies in the Jordan Rift Valley, a geographic feature formed by the Dead Sea Transform (DST). This left lateral-moving transform fault lies along the tectonic plate boundary between the African Plate and the Arabian Plate. It runs between the East Anatolian Fault zone in Turkey and the northern end of the Red Sea Rift offshore of the southern tip of Sinai.

(Wadi is the Arabic term for a river valley with a small or intermittent stream; Nahal is the equivalent in Hebrew. The two terms are often used interchangeably in English names for the same body of water.)

The water of Wadi Hassa is now completely consumed in Jordan.[19] The Jordan River, which passes through the Sea of Galilee, has been substantially diverted. It currently only contributes about one-sixth of the inflow to the Dead Sea, less than direct rainfall.[19]

The Wadi Mujib valley, 420 m below the sea level in the southern part of the Jordan valley, is a biosphere reserve, with an area of 212 km2 (82 sq mi).[21] Rainfall is scarcely 100 mm (4 in) per year in the northern part of the Dead Sea and barely 50 mm (2 in) in the southern part.[22] The Dead Sea zone's aridity is due to the rainshadow effect of the Judaean Mountains. The highlands east of the Dead Sea receive more rainfall than the Dead Sea itself.

To the west of the Dead Sea, the Judaean mountains rise less steeply and are much lower than the mountains to the east. Along the southwestern side of the lake is a 210 m (700 ft) tall halite mineral formation called Mount Sodom.

There are two contending hypotheses about the origin of the low elevation of the Dead Sea. The older hypothesis is that the Dead Sea lies in a true rift zone, an extension of the Red Sea Rift, or even of the Great Rift Valley of eastern Africa. A more recent hypothesis is that the Dead Sea basin is a consequence of a "step-over" discontinuity along the Dead Sea Transform, creating an extension of the crust with consequent subsidence.[citation needed]

During the late Pliocene-early Pleistocene, what is now the valley of the Jordan River, Dead Sea, and the northern Wadi Arabah was repeatedly inundated by waters from the Mediterranean Sea.[23] The waters formed in a narrow, crooked bay that is called by geologists the Sedom Lagoon, which was connected to the sea through what is now the Jezreel Valley.[citation needed] The floods of the valley came and went depending on long-scale changes in the tectonic and climatic conditions.[23]

The Sedom Lagoon extended at its maximum from the Sea of Galilee in the north to somewhere around 50 km (30 mi) south of the current southern end of the Dead Sea, and the subsequent lakes never surpassed this expanse. The Hula Depression was never part of any of these water bodies due to its higher elevation and the high threshold of the Korazim block separating it from the Sea of Galilee basin.[24]

The water levels and salinity of the successive lakes (Amora, Lisan, Dead Sea) have either risen or fallen as an effect of the tectonic dropping of the valley bottom, and due to climate variation. As the climate became more arid, Lake Lisan finally shrank and became saltier, leaving the Dead Sea as its last remainder.[23][24]

From 70,000 to 12,000 years ago, Lake Lisan's level was 100 to 250 m (330 to 820 ft) higher than its current level, possibly due to lower evaporation than in the present.[26][27] Its level fluctuated dramatically, rising to its highest level around 26,000 years ago, indicating a very wet climate in the Near East.[28] Around 10,000 years ago, the lake's level dropped dramatically, probably even lower than today. During the last several thousand years, the lake has fluctuated approximately 400 m (1,300 ft), with some significant drops and rises. Current theories as to the cause of this dramatic drop in levels rule out volcanic activity; therefore, it may have been a seismic event.

The Dead Sea has a hot desert climate (Kppen climate classification BWh), with year-round sunny skies and dry air. It has less than 50 millimetres (2 in) mean annual rainfall and a summer average temperature between 32 and 39 C (90 and 102 F). Winter average temperatures range between 20 and 23 C (68 and 73 F). The region has weaker ultraviolet radiation, particularly the UVB (erythrogenic rays). Given the higher atmospheric pressure, the air has a slightly higher oxygen content (3.3% in summer to 4.8% in winter) as compared to oxygen concentration at sea level.[29][30] Barometric pressures at the Dead Sea were measured between 1061 and 1065 hPa and clinically compared with health effects at higher altitude.[31] (This barometric measure is about 5% higher than sea level standard atmospheric pressure of 1013.25 hPa, which is the global ocean mean or ATM.) The Dead Sea affects temperatures nearby because of the moderating effect a large body of water has on climate. During the winter, sea temperatures tend to be higher than land temperatures, and vice versa during the summer months. This is the result of the water's mass and specific heat capacity. On average, there are 192 days above 30 C (86 F) annually.[32]

In the 19th century and the early 20th century, the surface layers of the Dead Sea were less salty than today, which resulted in an average density in the range of 1.15-1.17 g/cm3 instead of the present value of around 1.25 g/cm3. A sample tested by Bernays in the 19th century had a salinity of 19%. By the year 1926, the salinity had increased[34][35] (although it was also suspected that the salinity varies seasonally and depends on the distance from the mouth of the Jordan).

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