Fish Ladder
A fish ladder, also known as a fishway, fish pass or fish steps, is a structure on or around artificial barriers such as dams and locks to facilitate diadromous fishes' natural migration. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps hence the term ladder into the waters on the other side. The velocity of water falling over the steps has to be great enough to attract the fish to the ladder, but it cannot be so great that it washes fish back downstream or exhausts them to the point of inability to continue their journey upriver.
via Fish ladder – Wikipedia, the free encyclopedia.
Armillaria Ostoyae
Armillaria ostoyae is a fungus commonly known as a Honey mushroom, and sometimes called Shoestring Rot.
This is the most common variant in the western U.S., of the group of species that all used to share the name Armillaria mellea. Armillaria ostoyae is quite common on both hardwood and conifer wood in forests west of the Cascade crest. The mycelium attacks the sapwood and is able to travel great distances under the bark or between trees in the form of black rhizomorphs (“shoestrings”).
A mushroom of this type in the Malheur National Forest in the Strawberry Mountains of eastern Oregon, U.S. was found to be the largest fungal colony in the world, spanning 8.9 square kilometres (2,200 acres) of area. This organism is estimated to be 2,400 years old. The fungus was written about in the April 2003 issue of the Canadian Journal of Forest Research. While an accurate estimate has not been made, the total mass of the colony may be as much as 605 tons. If this colony is considered a single organism, then it is the largest known organism in the world by area, and rivals the aspen grove “Pando” as the known organism with the highest living biomass.
Pando the Trembling Giant
Pando (or The Trembling Giant) is a clonal colony of a single male Quaking Aspen (Populus tremuloides) located in the U.S. state of Utah, all determined to be part of a single living organism by identical genetic markers and one massive underground root system, although whether it is a single tree is disputed, as it depends of one’s definition of an individual tree.
The plant is estimated to weigh collectively 6,000 tonnes (6,615 tons), making it the heaviest known organism. The root system of Pando is claimed by some to be among the oldest known living organisms in existence at 80,000 years of age, though the method used to produce this estimate (an estimate on when climatic conditions were last suitable for seedling germination) is not supported by current evidence of germination.
Grove of Titans
The Grove of Titans is a redwood grove, including several massive redwood trees, in Northern California. The largest coastal redwood in the grove is Lost Monarch.
The Grove of Titans was discovered May 11, 1998, by Stephen Sillett, and naturalist Michael Taylor. The location of the grove has not been disclosed to the general public. The discovery implies that Sillett and Taylor are the first to realize and declare the significance of the grove, not that they are the first ones to have seen the grove. The grove’s botanical significance is near equal with Atlas Grove to the south.
General Sherman
General Sherman is the name of a Giant Sequoia with a height of 275 feet (83.8 metres). As of 2002, the volume of its trunk measured about 1487 cubic meters, making it the largest non-clonal tree by volume. The tree is located in the Giant Forest of Sequoia National Park in the United States, east of Visalia, California. The tree is believed to be between 2,300 and 2,700 years old.
In 1879, it was named after American Civil War general, William Tecumseh Sherman, by naturalist James Wolverton, who had served as a lieutenant in the 9th Indiana Cavalry under Sherman. In 1931, following comparisons with the nearby General Grant tree, General Sherman was identified as the largest tree in the world. One upshot of this process was that wood-volume was widely accepted as the defining factor in establishing the world’s largest tree.
In January 2006 the largest branch on the tree (seen most commonly, in older photos, as an “L” or golf-club shape, protruding from about 1/4th down the trunk) broke off. There were no witnesses to the incident, but the branch—bigger around than the trunks of most trees, with a diameter of over 2 m (6 feet) and a length of over 30 m (100 feet)—smashed part of its enclosing fence and cratered the pavement of the walkway surrounding the sequoia. The breakage, however, is not believed to be indicative of any abnormalities with the tree’s health, and may even be a natural defense-mechanism against adverse weather conditions. The branch loss did not change the General Sherman’s status as the largest tree, as its size has been calculated using measurements of trunk volume, excluding branches.
via General Sherman (tree) – Wikipedia, the free encyclopedia.
Nature Sound Clips
Free, public domain sound clips available from the US Fish and Wildlife Service. Includes ducks, geese, loons, shorebirds, alligators, frogs, snakes, bats, bears, elk, wolves, and others. Pretty neat!
Cyanide fishing
Cyanide fishing is an illegal form of fishing commonly known as poaching common in South East Asia, which usually uses the chemical compound sodium cyanide. Since 2000, increasing restrictions on illegal dynamite fishing have led to an increasing growth in this indiscriminate method – particularly as it can be used without generating noise. The use of cyanide as a fishing technique was first documented in the Philippines in 1962. More than 150,000 kg of cyanide is believed to be used in the Philippines annually by the aquarium trade and more than a million kg have been used since the 1960’s.
In seawater sodium cyanide breaks down into sodium and cyanide ions. In humans, the latter blocks the oxygen-transporting protein haemoglobin; the haemoglobin in fish is closely related to that of humans, and can combine with oxygen even faster. Through the irreversible combining of cyanide ions onto the active structural domain, oxygen is prevented from reaching the cells, and an effect similar to carbon monoxide poisoning results. Coral polyps, young fish and spawn are most vulnerable; adult fish can take somewhat higher doses. The use of cyanide is known to cause mortality on laboratory corals in measured doses, however this data is very difficult to quantify in regard to wild populations. In humans ingestion or breathing in of cyanide leads to unconsciousness within a minute; asphyxiation follows. Lower doses lead to temporary or permanent disability and/or sensory failure. This is a constant danger for the fishermen; there are many local accounts of such “occupational accidents”, but such incidents are not recorded in official statistics or statements.
The fishermen dive into the sea usually without artificial breathing aids, although some use illegal and highly-dangerous apparatus whereby compressed air is sent down thin breathing tubes. When they reach the coral reefs, they spray the poison between the individual layers, after which the yield is collected. Edible fish, of which a number are sold for general consumption, are first placed for ten to fourteen days in fresh water for “rinsing”. Recent studies have shown that the combination of cyanide use and stress of post capture handling results in mortality of up to 75% of the organisms within less than 48 hours of capture. With such high mortality numbers, a greater number of fish must be caught in order to supplement post catch death.
Bowerbird
The most notable characteristic of bowerbirds is the extraordinarily complex behavior of males, which is to build a bower to attract mates. Depending on the species, the bower ranges from a circle of cleared earth with a small pile of twigs in the center to a complex and highly decorated structure of sticks and leaves — usually shaped like a walkway, a small hut or a maypole — into and around which the male places a variety of objects he has collected. These objects — usually strikingly blue in hue — may include hundreds of shells, leaves, flowers, feathers, stones, berries, and even discarded plastic items or pieces of glass. The bird spends hours carefully sorting and arranging his collection, with each object in a specific place; if an object is moved while the bowerbird is away he will put it back in its place. No two bowers are the same, and the collection of objects reflects the personal taste of each bird and its ability to procure unusual and rare items (going as far as stealing them from neighboring bowers). At mating time, the female will go from bower to bower, watching as the male owner conducts an often elaborate mating ritual and inspecting the quality of the bower. Many females end up selecting the same male, and many underperforming males are left without mates.
In a striking example of what is known as the “transfer effect,” bowerbird species that build the most elaborate bowers are dull in color and show little variation between male and female, whereas in bowerbird species with less elaborate bowers the males have bright plumage. Presumably, evolution has “transferred” the reproductive benefits of bright male plumage (common among polygamous birds) to elaborate bowers, allowing males to display their fitness by means other than physical characteristics that would appear to attract predation.
This complex mating behavior, with highly valued types and colors/decorations that in many species vary in attractiveness from year to year like fashion trends, has led some researchers to regard the bowerbirds as the most advanced of any species of bird. It also provides some of the most compelling evidence that the extended phenotype of a species can play a role in sexual selection and indeed act as a powerful mechanism to shape its evolution, as seems to be the case for humans.
Bowerbird – Wikipedia, the free encyclopedia