Rivers glowing

[Red Scarab]

Sunday night dropped a few shads in river and every thing lit up including the leader. You could even see the wash from under the boat like someone was holding a spot light. Any answers

[TCiam]

I wouldn't doubt if it had something to do with
all that toxic waste they're dumping in the river from Deepwater that they say is totally neutralized.....Yea Right!!!!!! :mad:

[Billy BaitSlinger]

Dinoflagellates - photoplankton ?

I've seen tons of it in tropical waters; i.e. La Parguera, PR. Quite spectacular under a new moon.

Never heard of or saw any around here, though.

[snichols]

I've seen it numerous times in the Delaware bay but never in the river.

[eddy]

jellyfish?

[capbar]

Billy bait slinger's answer sounds right. I've seen it here occasionally. Jellyfish also "light up' like that also. Often while throwing the castnet in the marina at night I'll come up with a net full of glowing jellies.

[Bawugna]

If you get a real close look at the "glows" you might be able to make out defined shapes. If they are an oval to round shape, it is very likely they are small jellies that glow when bumped or disturbed. I have seen them on some nights so bright that the entrire outline of my boat was clearly visible. Each time the boat settled into the water after hitting a wave a giant voosh of glowing lilght would disperse in all directions! THere are some nights when they are so thick in the drink that lighting one's way is not necessary because mother nature is alredy doing it for you.

You mention that this is in the river, What river? If the water is salt or strong brackish, jellies are the most likely answer.

[capthersch]

Billy Bait Slinger is correct.
When diving at night you could turn out your light and rotate your hand rappidly and it would light up as if it had a light of its own.
You could see the entire outline of another diver if all the underwater lighting was turned off and he was moving. Truly facinating. When you stopped moving it would get pitch dark.
These organisms live in all types of water, but are more abundant in salt and brackish waters.

[ 10-13-2004, 11:30 AM: Message edited by: capthersch ]

[sunnydaze]

Yup, probably an algae bloom of dinoflagellates.


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For more;
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http://www.microbeworld.org/htm/aboutmicro/microbes/types/protista.htm
"Some species glow in the dark in a process called bioluminescence. These species contain a compound called luciferin (the same compound found in fireflies). The glow increases markedly if the algae cells are agitated, as when a ship churns through the water."

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Dinoflagellata: Life History and Ecology
http://www.ucmp.berkeley.edu/protista/dinoflaglh.html

http://www.elenas-vieques.com/bioluminescent.html
"Almost all marine bioluminescence is (greenish) blue in color, for two related reasons. First, blue-green light (wavelength around 470 nm) transmits furthest in water. The reason that underwater photos usually look blue is because red light is quickly absorbed as you descend. The second reason for bioluminescence to be blue is that most organisms are sensitive only to blue light.

The luminescence of a single dinoflagellate is readily visible to the dark adapted human eye. Most dinoflagellates emit about 6e8 photons in a flash lasting only about 0.1 second. Much larger organisms such as jellyfish emit about 2e11 photons per second for sometimes tens of seconds. The intensity of luminescence by photosynthetic dinoflagellates is strongly influenced by the intensity of sunlight the previous day. The brighter the sunlight the brighter the flash."

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Bioluminescence Questions and Answers
http://siobiolum.ucsd.edu/Biolum_q&a.html

[Teaserfish]

are they harmful to the water?

[sunnydaze]

Teaserfish, if it's a toxic bloom then yes.

50% of all dinoflagellates are predators that feed on other organisms, the other 50% are photosynthetic and derive their energy from the sun.

Note: Pfiesteria (causes fish lesions) is also a dinoflagellate.


Sorry for the long post, but I wanted to keep everything together for future reference.

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Harmful Bloom Determination
http://www.bigelow.org/hab/cause.html

http://www.ucmp.berkeley.edu/protista/dinoflaglh.html

http://www.nmnh.si.edu/botany/projects/dinoflag/
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Dinoflagellates may produce their own light chemically.

The Dinoflagellata are sometimes called Pyrrhophyta , meaning "fire plants". This is because some species are capable of bioluminescence, in which chemicals made by the organism produce light in a chemical reaction. The dinoflagellates begin to glow as it gets dark, but will brighten considerably when agitated, such as in the wake of a ship. The phenomenon was first noted in the genus Noctiluca, which resulted in its name ("night light"), but the reaction is now known to occur in several marine species.

The chemical reaction itself occurs when the compound luciferin (a substrate chemically similar to a chlorophyll precursor), is oxidized by the enzyme luciferase in the presence of ATP and oxygen. This reaction and similar ones occur in a number of unrelated organisms, both prokaryotic and eukaryotic.

Blooms of dinoflagellates produce "red tides" which injure marine life.

The most dramatic effect of dinoflagellates on their environment occurs in coastal waters during the warmer season, usually mid to late summer. At this time, an upwelling occurs in the ocean, bathing the surface plankton in nutrients from the bottom of the ocean. The surplus of nutrients triggers a "bloom" of photosynthetic dinoflagellates, whose population density may jump to more than 20 million per liter along some coasts. This high density may color the water golden or red, and is called a "red tide".

In some species these blooms are associated with the production of neurotoxins, poisons which injure the nerves of marine life that feed on the dinoflagellates. The result may be massive kills of fish and shellfish, as well as other forms of marine life. If animals containing these toxins are eaten by humans, the result may be illness or even death.

The neurotoxins affect muscle function, preventing normal transmission of electrochemical messages from the nerves to the muscles by interfering with the movement of sodium ions through the cellular membranes. Humans may be poisoned by eating fish, a condition known as ciguatera, or by eating shellfish, such as clams or mussels, and is then called paralytic shellfish poisoning, or PSP. The resulting condition is serious but is not usually fatal. Lethal concentrations lead to death from respiratory failure and cardiac arrest within twelve hours of consumption.

The most common dinoflagellate toxin is saxitoxin, a neurotoxin 100,000 times more potent than cocaine. It has been found in North American shellfish from Alaska to Mexico, and from Newfoundland to Florida. The most notorious producer of saxitoxin on the west coast of North America is Protogonyaulax catenella, and on the east coast Gessnerium monilatum. Both have been known to cause PSP.

A second form of toxin, found in the dinoflagellate Ptychodiscus brevis, is brevitoxin, an assemblage of various polyether alcohols which produce fish kills, and may also cause poisoning in humans when it accumulates in the tissues of shellfish. The rule of thumb is that shellfish should only be eaten during months with an "R" in them, and not during May to August.


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>>>Other Causes of Fish Lesions and Fish Kills
http://www.habhrca.noaa.gov/pfiesteriafacts.html

Fish kills are situations of short duration, usually hours or days, when masses of dead and dying fish are observed. These can have many causes, including depleted oxygen, sudden changes in factors such as salinity and temperature, blooms of various kinds of harmful or toxic algae, infectious disease agents, and other environmental changes. Coastal waters contain a variety of pathogens that can cause the kinds of ulcers that were attributed solely to Pfiesteria during the North Carolina events. A number of recent research reports corroborate this view. One study from North Carolina (Paerl and Pinckney 1996) provides credible evidence that the fish kills observed during and outside Pfiesteria outbreak periods were caused by low oxygen events that cause fish to suffocate. Generally Pfiesteria outbreaks have occurred in warm weather in slow moving tidal waters having low oxygen levels and high nutrient loads.

Excess nutrients are common pollutants in coastal waters. Chief sources of nutrient pollution in coastal areas are sewage treatment plants, septic tanks, runoff from suburban landscapes and agricultural operations, and air pollutants that settle on the land and water. Excess nutrients can provide an abundance of the phytoplankton cells that Pfiesteria commonly use as food.

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About half the species of dinoflagellates are photosynthetic; the other half are predators that attack bacteria, algae, and even fish.

Dinoflagellate neurotoxins can concentrate in the bodies of shellfish and fish that eat the algal cells, in turn causing people who eat these seafoods to come down with illnesses such as paralytic shellfish poisoning and ciguatera (a combination of gastrointestinal, neurological, and cardiovascular disorders.)

[ 10-14-2004, 09:28 AM: Message edited by: sunnydaze ]