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What Are Coral Reefs - Introduction to Our Underwater World

2013-03-29T01:19:53Z

Planet3grip: Die Seite wurde neu angelegt: „[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Learning about Coral Reefs [http://blog.steve…“

[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/introduction-to-the-underwater-world/ What Are Coral Reefs] - Learning about Coral Reefs
[http://blog.stevenwsmeltzer.com/what-are-coral-reefs/ Coral reef systems] are made up of tiny animals which belong to the class anthozoans, the major class of organisms within the phylum cnidaria (the "c" is silent). Cnidaria has greater than 6,000 recognized species of jellyfish, sea pansies, sea anemones and sea fans. Corals, after their larvae phase, no longer move but are fixed in one place. This type of animal is known as a sessile animal.

Coral reef colonies are composed of millions of these tiny, cup-shaped animals called polyps. A single coral polyp might be as big as a saucer or smaller than the head of a pin. Millions of polyps functioning together in a cooperative colony generation after generation make the limestone skeletons that form the framework of the magnificent coral reef. Corals begin life in tropical waters as free-floating larvae. After a relatively short period of time, the larva finally attaches itself to a hard surface and becomes a polyp. [http://www.stevenwsmeltzer.com Coral reef] colonies reproduce both sexually and asexually. To reproduce, the coral polyps release both eggs and sperm in the water. (This is also known as coral spawning.) One kind of asexual reproduction takes place when fragments of coral are broken off as a consequence of storm storms. The broken pieces of corals usually survive and continue to grow and make a new colony. This process is known as as "fragmentation". Corals live in colonies consisting of many individuals, each of which is called polyp. They produce a hard calcium carbonate (rock-like) skeleton, that serves as a uniform base or substrate for the colony. This skeleton enables two basic functions, first for the coral itself it provides shelter, as the polyps can contract into the structure if predators draw near and second this same skeletal structure is what builds up the coral reefs over a period of time. The calcium carbonate is produced at the foot of the polyps, consequently the living portion of the coral colony occurs at the surface of the skeletal structure, totally covering it. The calcium carbonate deposited by the colony continually adds to the size of the general structure and therefore the growth of the reef. The expansion of these coral reef structures differs greatly, depending on the species of coral and environmental conditions-- ranging from 0.3 to 10 centimeters per year. Different varieties of coral assemble structures of different dimensions and shapes such as brain corals, fan corals, encrusting corals, etc., producing marvelous diversity and complexity in the coral reef ecosystem. Various coral species tend to be seperated into characteristic zones on a reef, separated out by competition with other species and by environmental conditions. The skeletons of stony corals are secreted by the lower part of the polyp. This method produces a cup, called the calice, in which the polyp sits. The walls surrounding the cup are known as the theca, and the base is called the basal plate. Thin, calcareous septa (sclerosepta), that gives structural integrity, protection, and an enlarged surface area for the polyp's soft tissues, extend upward from the basal plate and radiate inward from its external wall. From time to time, a polyp will lift off its base and secrete a new floor to its cup, creating a new basal plate above the old one. This creates a minute chamber in the skeleton. When polyps are physically stressed or under probable attack, they move down into the calice so that practically no part is exposed above the skeletal platform. This protects the organism from predators and the elements (Barnes, R.D., 1987; Sumich, 1996). Corals have only a limited degree of organ development and consists of three basic tissue layers: an external layer or epidermis, an inner layer of cells lining the gastrovascular cavity (an internal space for digestion) and a layer known as the mesoglea between the other two layers Barnes, R.D., 1987. Corals feed by reaching out with tentacles to catch prey such as small fish and planktonic animals (any drifting organisms, animal, plant, archaea or bacteria that inhabit the pelagic zone of the oceans). See Also: Creatures of the Coral Reefs Resources: Marine Species Galleries: Crustaceans and Echinoderms Moray Eels Coral Reef Images Pictures of Fish Sea Turtles Detailed Information on select Marine Species: Caribbean Fish Hawaiian Fish Sponges Crustaceans, Invertebrates, Mollusks, Echinoderms

Best Point and Shoot Cameras

2013-03-17T20:17:40Z

Planet3grip:

When considering a water-resistant point and shoot camera lens speed or the "f-stop" rating. The faster the lens., e.g., the lower the f-stop number the better and the more light that the lens allows into the digital camera making higher qualtity less noisy images. f2.0 is very fast and f3.9 is ok, but doesn't take as good a picture in lower light situations and will typically be a little more difficult to focus in reduced light conditions. A different characteristic would be the capability of the zoom lens and how much of the "zoom" is created by the lens compared to a digital zoom, where software is generating the zooming effect. Another characteristic for taking pictures up close would be the ability to take macro photos and how near to the subject matter you can get the camera and still focus. One additional feature to think about would be the capability to shoot video and the video processors speed, e.g., does the camera have a high speed video processor meaning it will capture over 200 frames per second (fps), or else does it have a low speed video processor. A faster vidwo processor will create higher quality videos.

The critiques of the top digital cameras listed below offers an interesting synopsis of several of the best point and shoot water-resistant cameras along with a suggestion on the top camera.

Waterproof cameras reviewed:
<ol>
<li>Panasonic Lumix TS4 12.1 TOUGH Waterproof Digital Camera with 4.6x Optical Zoom
<li>Nikon COOLPIX AW100 16 MP CMOS Waterproof Digital Camera with GPS and Full HD 1080p Video
<li>Canon PowerShot D20 12.1 MP CMOS Waterproof Digital Camera with 5x Image Stabilized Zoom 28mm Wide-Angle Lens a 3.0-Inch LCD and GPS Tracking
<li>Fujifilm XP170 Compact Digital Camera with 5xOptical Zoom Lens
<li>Olympus Stylus TG-830 iHS Digital Camera with 5x Optical Zoom and 3-Inch LCD
<li>Pentax Optio WG-1 Adventure Series 14 MP Waterproof Digital Camera with 5x Wide-Angle Optical Zoom
<li>Olympus TG-1iHS 12 MP Waterproof Digital Camera with 4x Optical Zoom
</li>
</ol>

For anybody who is prepared to spend about $1,000 to obtain the [http://www.squidoo.com/best-waterproof-point-and-shoot-camera best waterproof point and shoot camera] setup then one of the finest underwater cameras in the extreme digital camera market is certainly the Olympus TG-1 iHS. This camera when purchased with the optional Olympus underwater case and strobe enables the diver to take photographs at a depth of up to 130 feet and also makes a very decent entry level underwater camera for any diver. TotalThe e investment involves the camera, a rugged housing that enables the diver to take the camera down to 135 feet and an independent strobe that delivers the ability to photograph in a varity of diverse situations.

USS Kittiwake dive

2013-03-11T09:14:36Z

Planet3grip:

This is a great shipwreck dive in grand cayman and one of the best in the caribbean The USS Kittiwake has been on the reef for a about 18 months ago and the site is aging well. The ship has five decks, is a little over76 meters in length amd 12 meters in beam and around 50 feet high. The vessel was designated specifically for submarine rescue and was launched on July 10, 1945 and she was reefed in Grand Cayman in January 2011.

The following is an overview of the dive, a little history and other information on the subject of the shipwreck and an synopsis of what one can find on the wreck. You can see the complete [http://stevenwsmeltzer.com/gallery/Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/ photo gallery] on the web site and/or see the blog entry for the [http://blog.stevenwsmeltzer.com/dive-site-reviews-and-listings/dive-sites/scuba-diving-grand-cayman-uss-kittiwake-shipwreck/ USS Kittiwake] for additional data on the shipwreck along with a history about the ship.

The Dive:

The ship was reefed In january 2011 off the north end of Seven Mile Beach in Grand Cayman.

There are 5 decks on the 47 foot tall [http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000Wcb0w0RopvI USS Kittiwake]. To meet caymanian requirements for wrecks, a portion of the upper mast was removed. The are two bridges on the upper decks (both an external and internal bridge to allow operations in heavy seas) along with the radio and navigation room. The sonar has been removed from the ship. The Captain and executive officer's quarters are also on the upper decks.

On the main deck, from bow to stern, internally you will find a number of different rooms or work areas including the recompresson chambers, the rec room and toolshop. You will also see a large [http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000nrOSPnFJRtU a-frame structure] on the stern that rescue divers, along with the diving bell which was used to bring back divers to the ship and then to the recompression chambers

The crews quarters, the engine room and medical facilities are located below the main deck along with ,[http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000QmV9jUuDJyQ air bank storage] and compressors, as well as the steering gear, shaft, gyro, ammunition lockers, cold storage and barber shop to name a few areas. While there are now a number of big[http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000evHtkg3GaYQ access holes] both vertically and horizontally, all of the space on the vessel was used when she was in service.

Make sure to plan your dive adequately. I would recommend heading to the stern prior to entering into the shipwreck to get pictures around the[http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000MlfKl.47lgI "USS Kittiwake" logo] on the the backof the ship and in addition get photos by the propeller. For Divers that intend on penetrating the shipwreck, you can then make your way to the top of the ship and go into the funnel which is on on the Bridge Deck. If you do not intend on penetrating the shipwreck you should start your investigation of the ship on the main deck just above the Screw..

The [http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000ndu7PcxF.bM funnel entry makes an excellent underwater photograph] . try silhouetting your dive partner in the shaft diving down into the shipwreck. You can exit into the ship on several of the decks including the first platform or in the hold. The cargo hold should only be entered by experienced advanced divers. When you exit to the first platform you will be able to see the Engineering logo in the Motor Room section. This section can be accessed easily and can be the subject of a very good underwater photo close to the "[http://stevenwsmeltzer.com/gallery-image/USS-Kittiwake-Grand-Cayman/G0000JtpXOPWAQac/I0000Y0UeUwX5JJc Engineering Mural]". The sediment can be heavy in this location so you must move gradually to prevent clouding up the water. For advanced wreck divers you can also check out shaft alley as well as the front hold areas of the shipwreck. For others you can check out a variety of areas on the first platform and then start going up deck by deck and then finally arriving at the Bridge (Pilot House) where you can do you safety stop as it is at about 5 to 6 meters or 15 to 18 feet.

Review photos of additional [http://stevenwsmeltzer.com/gallery/Shipwrecks/G0000OtMyTETA74I/ shipwrecks] on http://www.stevenwsmeltzer.com or visit his [http://blog.stevenwsmeltzer.com/dive-site-reviews-and-listings/dive-sites/scuba-diving-grand-cayman-uss-kittiwake-shipwreck/ blog] for reviews of specific shipwrecks.