Asa Forman
Dr. Lee and Dr. Quillin
Falmouth Field School
22 January 2016
Bioluminescent Organisms
From January 5th to January 15th, 2016, I and several other students from the Post Oak High School went on a trip to Falmouth, a small town on the Northwest Coast of Jamaica. While we were there, we learned about the Falmouth Port, the architecture of the 19th century, the people in Falmouth, the story behind why Jamaicans run so fast, and many more interesting topics. During the trip, our group also got to experience many fun and involving activities, such as visiting John Tharp's original house, rafting on the Martha Brae River, and visiting the first Persian Water Wheel in Falmouth. We also experienced something very surreal: a bioluminescent lagoon. When we jumped into the lagoon, some microorganisms in the lagoon became irritated and illuminated themselves. The organisms were called dinoflagellates. However, before talking about dinoflagellates, I think it would be helpful to acquaint you with what bioluminescence is and other bioluminescent creatures.
Bioluminescence is a form of chemiluminescence, a chemical reaction that produces light. The light that is produced from these creatures is what one might describe as a cold light, as less than 20% of heat is created by bioluminescent light. The light from these bioluminescent organisms is created when a compound called luciferin combines with oxygen, creating a light (“Bioluminescence”). Some bioluminescent organisms create something called a photoprotein, which is like a premade bomb on a hairpin trigger. However, the trigger can only be activated by a specific ion of an element- typically, this element is Calcium (Ocean). When this light is created it generally has a blueish-green tint to it, but some organisms illuminate in other colors. For example, the firefly, another bioluminescent organism, has an abdomen that illuminates yellow, and the railroad worm has a head that glows red. Some bioluminescent organisms don't glow continuously, and the dinoflagellates we swam with are no exception (Education, National Geographic). Many bioluminescent organisms just flash their lights at times of need. Some of these bioluminescent creatures live deep down towards the bottom of the ocean floor, allowing them to communicate in the darkness (“Creatures”). Other bioluminescent organisms have uses for their self-produced lights besides communication, such as for defending themselves, warding off opponents and predators, attracting mates, and more. For example, the male Caribbean ostracod, an extremely small crustacean, illuminates its upper lip to find a female companion. Another good example is the deep-sea squid which detaches its bioluminescent arms as a distraction if there happens to be a predator around (Education, National Geographic).
Another important fact about bioluminescence is that it is drastically different than fluorescence, and it is surprisingly easy to get the two mixed up. For example, lots of coral reefs have living plants on them, in fact all coral reefs are like one big plant. On these coral reefs some of the plants tend to glow. Now you might think,“Plant? Light? Bioluminescence!” but no, what the reef is actually doing is absorbing light and then re-emitting it, whereas bioluminescent light involves a chemical reaction inside the body of a bioluminescent organism (Education, National Geographic). Many things in the sea are bioluminescent including bacteria, algae, jellyfish, worms, crustaceans, sea stars, fish, and sharks, not to mention microorganisms such as dinoflagellates. Dinoflagellates happened to be the organisms we swam in and are actually quite fascinating (The Ocean Portal Team).
Dinoflagellates, like I mentioned earlier, are microorganisms, but more specifically they are single celled protists. Dinoflagellates were first found in 1773 by O. F. Muller. These organisms were estimated to have been conceived in the Ediacaran Era or earlier. To put the dates of the Ediacaran Era in perspective, the period lasted from one billion years ago to five hundred seventy million years ago. As we know it today there are 1,200 to 2,000 different species of dinoflagellates. The majority of dinoflagellates thrive mainly in saltwater; however, there are a few species that live in fresh and brackish water.. They typically have an outer membrane called the theca. The theca is made up of the thecal plates which distinguishes one dinoflagellate from the next. There are only two groups of dinoflagellates with thecal plates, namely the "armored" dinos and the "unarmored” dinos (Reef Central). There is another distinguishing characteristic of dinoflagellates. This regards whether or not the microorganism is photosynthetic or non-photosynthetic. Generally, a photosynthetic dinoflagellate is defined by living inside another organism (a host), after being swallowed and incorporated into the host's system. A non-photosynthetic dino is just the opposite. A non-photosynthetic actually feeds on different diatoms and protists (Diatoms are a major group of algae and are among the most common types of phytoplankton) (“Dinoflagellata”).
Besides being called and known as Dinoflagellates, Dinoflagellates have been called Pyrrophyta, meaning "fire plant." These "fire plants" are practically harmless except surprisingly, during the coastal season, they do have a big effect to the ecosystem. During this time all of the surface plankton receive excess nutrients from the bottom of their living area. This creates something called a bloom. When the bloom starts the water starts to turn a golden or a red. These colors appear because of the excess amount of Dinoflagellates that are in the water. It is said that over 20 million dinoflagellates can be in one litre of water. These "red tides" although they may seem harmless are not. The organisms that create these tides let out a toxin, most commonly the toxin is called saxitoxin, and it is very harmful to numerous of fish and shellfish (Dinoflagellata: Life History and Ecology).
Overall I would say that Dinoflagellates and bioluminescent organisms are extremely interesting and fascinating. At first, all I thought of the Bioluminescent organisms was "wow, this water lights up." But now I realize that there is many more things to know about the organisms than what meets the eye, especially Dinoflagellates.
Source: Inhabit.com
Several types of fungi are Bioluminescent, that is a Bioluminescent fungus above. According to the American Museum of Natural Science, Bioluminescent organisms have evolved over fifty times if their estimations are correct (Wynne Parry).
Source: Whoi.edu
This is an incredible picture of what a red tide might look like during the coastal season.
Source: Visitjamaica.com
These are the waters we swam in during our Bioluminescent experience.
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