Sea Life in the Georgia Embayment |
The inspiration for these pages on other sea life is obviously driven by my own growing fascination about what I find new at sea each time I go out. The other side of that is my growing sense that a lot of people are becoming increasingly aware of the sea. Each new view of Leatherback Turtle, spotted dolphin or new understanding of the role tiny micro-organisms play in the health of our planet surely gets the attention of more sea birders than me. On land we birders are knee deep in butterflies and dragonflies in the summer doldrums. Why should we be any less curious at sea. In fact, there are two new field guides that lend credence to this growing awareness. Audubon released Guide to Marine Mammals of the World in 2002, and Michael Tove has out his Guide to the Offshore Wildlife of the Northern Atlantic. In know both are at Amazon, and I believe they may be at ABA Sales as well. If the life of sea and its' environment fascinate you, then you might try Exploring Ocean Science, a 1996 textbook by K. Stowe, published by John Wiley and Sons. No telling where these pages will go. Each time the light bulb of understanding comes on I will add it here, and hopefully others will share it. Click the links below to go directly to other sea creature pages. Hit the back button on your browser to return to this page.
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The role of phytoplankton. This micro-algae is the foundation of the food web and ultimately leads to sustaining virtually all life in the sea. If that is not enough, phytoplankton perform the critical role of photosynthesis, and as a group play a major role in the maintenance of life on Earth. One type of phytoplankton, the diatoms, have been found in the sandy plain bottoms of the continental shelf of Georgia, creating a food web in these areas we often think of as the dead zone. When phytoplankton are being fed upon by larger organisms certain chemicals such as Dimethyl Sulfide are released. These chemicals provide an olfactory cue, likely attracting procellariiforme (tubenose) seabirds to the area. | |||||
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Phytoplankton |
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If phytoplankton above are the grasses of the sea, then the zooplankton known as copepods are the insects of the sea. They are the smallest and most abundant of the zooplankton and are just up the food chain from the micro-algae above. Copepods are equipped with mechanisms to move water around as they drift (plankton comes from the German 'drifters'), allowing them to filter out the phytoplankton on which they feed. There is a concise and witty summary of these tiny organisms from Sharon Gilman at Carolina Coastal University. She was kind enough to allow me to borrow from her material. Tune in at http://kingfish.coastal.edu/biology/sgilman/770PlanktonBenthos.htm | |||||
| Copepods | ||||||
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The weed or grass we all look for at sea as an indicator of the presence of sea birds is a kelp or brown algae, Sargassum natans and S. fluitans. Large beds of this free floating plant grow abundantly in the very clear lens of warm water of the Sargasso Sea, an area of the North Atlantic. The western-most boundaries of this sea are hundreds of miles off shore and southwest of Georgia. The Sargasso Sea drifts counterclockwise with the currents, and portions of it often break away into the Gulf Stream to move north. Frequently mats will be storm-blown even further in-shore. This cover provides shelter for a myriad of small sea life including the Sargassumfish, and is closely associated with the pelagic Bridled Tern. |
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| Sargassum | ||||||
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This floating mushroom with a flower on one end, Stomolophus meleagris, can be so numerous over near-shore reefs it can fill a water column 60 feet deep. The public seems to have a general misunderstanding of the role of medusae (jellies). This one is highly prized by the Japanese for use in salads, so I am told. We already know that marine turtles depend on jellies as a significant part of their diets. This one is harmless to humans. It's pretty obvious I don't know much about them either... |
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| Cannonball Jelly | ||||||
drawing by Jessie Sawyer |
There is little written about the flying fish. In fact I couldn't find agreement on whether it should be written as flying fish or flyingfish. I can only assume that the species we see off Georgia's coast is the species Cypelurus melanurus. It is about 8 to 10 inches long and is one of 23 species worldwide. Flying fish glide on greatly enlarged pectoral fins for distances of up to 100 meters. This is sometimes the most visible life form we see on pelagic trips, often outnumbering the seabirds we go to find. | |||||
| Atlantic Flying Fish | ||||||
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