question: How fast does scent travel in water?
comment: Scent travels as fast as the water travels. It doesn't have mobility on its own. You're simply detecting molecules of the associated substance as they reach you, carried by the water from the source. Similarly, scents in the air travel as fast as the air does.
passages: Other studies have shown that the harbor seal can distinguish between the hydrodynamic trails left by paddles of different sizes and shapes, a finding in agreement with what the lateral line in goldfish is capable of doing. Discrimination between different fish species might have adaptive value if it allows seals to capture those with highest energy content. Seals can also detect a hydrodynamic trail produced by a fin-like paddle up to 35 seconds old with an accuracy rate greater than chance. Accuracy diminishes as the trail becomes older.
  
  Section::::Mammals.:Pinnipeds.:Sea Lions.
   The difference in density between air and water causes smells (certain chemical compounds detectable by chemoreceptors) to behave differently. An animal first venturing out onto land would have difficulty in locating such chemical signals if its sensory apparatus had evolved in the context of aquatic detection.
  
  Section::::Anatomy and physiology.:Senses.:Lateral line system.
   A frequent hydrodynamic stimulus is a wake, consisting of eddies and vortices that an organism leaves behind as it swims, affected by the animal's size, swimming pattern, and speed. Although the strength of a wake decreases over time as it moves away from its source, vortex structure of a goldfish's wake can remain for about thirty seconds, and increased water velocity can be detected several minutes after production.
  
  Section::::Overview of hydrodynamic stimuli.:Uses of hydrodynamic stimuli.
   To find whether seals could actually follow hydrodynamic stimuli using their vibrissae rather than just detect them, a blindfolded harbor seal with headphones can be released into a tank in which a toy submarine has left a hydrodynamic trail. After protracting its vibrissae to the most forward position and making lateral head movements, the seal can locate and follow a trail of 40 meters even when sharp turns to the trail are added. When whisker movements are prevented with a mask covering the muzzle, the seal cannot locate and follow the trail, indicating use of information obtained by the whiskers.
   BULLET::::- "Super Scents": Smell is invaluable in hunting, protecting a species, mating, and navigation. Petrels use it to find fish in the open sea, springboks emit an 'alarm' odour to warn the herd of a predator, salamanders inject their females with aphrodisiac, and a salmon’s epic journey across the ocean to spawn and die is achieved through its sense of smell.
   Section::::Mammals.:Pinnipeds.:Seals.
  
  Research on the ability of pinnipeds to detect hydrodynamic stimuli was first done on harbor seals ("Phoca vitulina"). It had been unclear how seals could find food in dark waters. It was found that a harbor seal that could use only its whiskers for sensory information (due to being blindfolded and wearing headphones), could respond to weak hydrodynamic stimuli produced by an oscillating sphere within the range of frequencies that fish would generate. As with active touch, whiskers are not moved during sensing, but are projected forward and remain in that position.
   As Penelope clambers aboard, the entire crew and passengers evacuate the ship, spelling "LE PEW!" in the water. Pepé then emerges dripping wet and finds Penelope. First he asks her for a date, but then immediately leaps on her and smooches her. Penelope wriggles free and runs off. Pepé heads to Beauty Salon and dries himself with a hair dryer puffing his fur up, but then he brushes himself. Pepé then rushes to Penelope and smooches her again and she wriggles and rushes off. Pepé chases Penelope wherever she goes until Penelope escapes on the lifeboat. But as Penelope watches the ship drift away, Pepé emerges and Penelope has nowhere left to run.
   BULLET::::- - Royal Thai Navy
  
  BULLET::::- - Maritime Squadron of the Armed Forces of Malta
  
  BULLET::::- - SENAN
  
  BULLET::::- - Vietnam People's Army, taken from the former South Vietnam Navy
  
  Section::::Current.
   An olfactory sensation is called an odor. For a molecule to trigger olfactory receptor neurons, it must have specific properties. The molecule must be:
  
  BULLET::::1. volatile (able to float through the air)
  
  BULLET::::2. small (less than 5.8 x 10-22 grams)
  
  BULLET::::3. hydrophobic (repellant to water)
  
  However, humans do not process the smell of various common molecules such as those present in the air.
   More recently, studies on hydrodynamic detection in the California sea lion ("Zalophus californianus") have been done. Despite the structure of their mystacial vibrissae, different from those of seals, these sea lions can detect and follow a trail made by a small toy submarine. Sea lions use an undulatory pattern of tracking similar to that in seals, but do not perform as well with increased delay before they are allowed to swim and locate the trail.
  
  Section::::Mammals.:Pinnipeds.:Species differences in vibrissae.
   Section::::Diver searches.:Search patterns controlled by compass directions.:Swim-line search.
   BULLET::::1. not operating at nighttime
  
  BULLET::::2. not operating at specific areas of the ocean that are considered sensitive
  
  BULLET::::3. slow ramp-up of intensity of signal to give cetaceans a warning
  
  BULLET::::4. air cover to search for cetaceans
  
  BULLET::::5. not operating when cetaceans are known to be within a certain range
  
  BULLET::::6. onboard observers from civilian groups
  
  BULLET::::7. using fish-finders to look for cetaceans in the vicinity
  
  BULLET::::8. large margins of safety for exposure levels
  
  BULLET::::9. not operating when dolphins are bow-riding
  
  BULLET::::10. operations at less than full power
  
  BULLET::::11. paid teams of veterans to investigate strandings after sonar operation.
   BULLET::::- The time between pings is typically from 6 to 15 minutes.
   BULLET::::- Survey sonar accuracy: better than 20 m
  
  BULLET::::- Bottom penetration: 50 m (soft mud)
  
  Section::::Submerged Dragon 1.
   In another variant, some swim organizations simply have different sets of records for different equipment scenarios (e.g. wetsuit and non-wetsuit divisions), similar to the structure of free diving record keeping.
  
  Section::::Long-distance swimming in the Netherlands.
   BULLET::::11. On August 17, 2013, Belhedi swam between the Diomede Islands in a time of 39 minutes, covering 4 km in 2 °C and making the circuit from Russia to USA in a way different from that swum by Lynne Cox.
  
  BULLET::::12. On 15, 16, 17, 18 September 2018 Nejib Belhedi accomplished successfully 120 km Swim No Stop (Tunisia- Gulf of Gabes) from the Southern Salin Basin in Thyna-Sfax, through the middle of Boughrara Gulf to Jilj Island in 76 hours 30 minutes at the age of 66.This is included as the longest solo swim in sea by the World Open Water Swimming Association
   Each separate object must have its own independent track information. This is called track history, and this extends back for a brief span of time. This could be as much as an hour for airborne objects. The timespan for underwater objects may extend back a week or more.
  
  Tracks where the object produces a detection are called active tracks.
  
  The track is continued briefly in the absence of any detections. Tracks with no detections are coasted tracks. The velocity information is used to estimate antenna aiming positions. These are dropped after a brief period.
   A sediment trap mooring, consisting of five sediment traps (located at depths of 150, 275, 400, 800, and 1200 m), is also deployed near the study site. This mooring collects the downward flux of particulate material (Thunell et al. 2000; Thunell et al., 2007), derived both from the primary production at the surface and the terrestrial material from the mainland.
  
  "Satellite observations"
   Section::::1977.
   Since movement of an object through water inevitably creates movement of the water itself, and this resulting water motion persists and travels, the detection of hydrodynamic stimuli is useful for sensing conspecifics, predators, and prey. Many studies are based upon the question of how an aquatic organism can capture prey despite darkness or apparent lack of visual or other sensory systems and find that the sensing of hydrodynamic stimuli left by prey is probably responsible. As for detection of conspecifics, harbor seal pups will enter the water with their mother, but eventually ascend to obtain oxygen, and then dive again to rejoin the mother. Observations suggest that the tracking of water movements produced by the mother and other pups allows this rejoining to occur. Through these trips and the following of conspecifics, pups might learn routes to avoid predators and good places to find food, showing the possible significance of hydrodynamic detection to these seals.
   As of 2012, a small percentage of forensic limnology is used as evidence in courts. The presence of diatoms in air, food, drink, and close contact is not variable enough to be supportive evidence in determining locations of events. Even so, an investigation requires the use of forensic limnology in order to estimate time of death, location of drowning, and the determining of suspect. If the results of forensic limnology are not used in prosecution, the results are used to understand the crime.
   BULLET::::- Improve the measure of the time-averaged ocean circulation
  
  BULLET::::- Improve the measure of global sea-level change
  
  BULLET::::- Improve open ocean tide models
  
  Section::::Ocean altimetry.
   BULLET::::- Ship routing: Maps of currents, eddies, and vector winds are used in commercial shipping and recreational yachting to optimize routes.
  
  BULLET::::- Offshore industries: Cable-laying vessels and offshore oil operations require accurate knowledge of ocean circulation patterns, to minimize impacts from strong currents.
  
  BULLET::::- Marine mammal research: Sperm whales, fur seals, and other marine mammals can be tracked, and therefore studied, around ocean eddies where nutrients and plankton are abundant.
  
  BULLET::::- Fisheries management: Satellite data identify ocean eddies which bring an increase in organisms that comprise the marine food web, attracting fish and fishermen.
   The earliest measure of learning is "escape latency", which is the time it takes to find the platform. However, this measure is confounded by swimming speed, not necessarily a cognitive factor, and path length between point of origin and platform is a parameter more closely related to spatial learning. Further parameters are the Gallagher measure, the average distance to the platform, and the Whishaw corridor test, which measures time and path in a strip directly leading from swim-start to platform. Other parameters are measured during probe trials: the escape platform is removed and the mice or rats are allowed to search for it for a fixed time (often 60 seconds). Variables measured are time and path length in quadrants, time near platform, and platform crossings.
   Trails produced by live animals are more complex than that produced by a toy submarine, so the ability of seals to follow trails produced by other seals can also be tested. A seal is capable of following this center of this trail, either following the direct path of the trail or using an undulatory pattern involving crossing the trail repeatedly. This latter pattern might allow the seal to track a fish swimming in a zigzagging motion, or assist with tracking weak trails by comparing the surrounding water with the prospective trail.
  
presuppositions: Scent can travel at it's own speed in water.
corrections: Scent travels as fast as the water travels, it does not have mobility on its own.
raw_presuppositions: Scent can travel at it's own speed in water. Scent can travel at it's own speed in water.
raw_corrections: Scent travels as fast as the water travels, it does not have mobility on its own. Scent travels as fast as the water travels, it does not have mobility on its own.