Wednesday, February 15, 2012

FTV 2/15/12 Virgin Islands Kayak Trip

In the Virgin Islands a group of cadets and I went on a snorkel tour of a small island where hard bottom environments are found. These ecosystems are just off the shore where rocks and ancient coral reefs jut out of the ocean floor and become habitats for a variety of fishes and invertebrates. Hard bottom reefs are well-populated habitats because the hiding places and hard structure of the reef provide shelter for many smaller animals. The abundance of smaller animals at the reef provides food for many larger animals. Fishes in hard bottom reefs are affected by watersheds in several ways. The nutrients carried by watersheds support the microscopic plants in the ocean that are the basis of all the food webs in the ocean, including the ones reef fish are dependent on. Pollutants in watersheds can also affect reef fishes, because they will eventually flow into and contaminate the ocean, and can be detrimental to the fishes̢۪ health. Many reef fishes are particularly affected by contamination in watersheds, because their larvae are carried inshore by currents to estuaries and salt marshes. These estuaries and salt marshes act as nurseries for these young fishes. Because these habitats do not have as much water in them as the ocean and they are also having water flow through them from watersheds, any pollutants in the watershed will be in these habitats in high concentrations. These high concentrations of contaminants can have devastating effects on the vulnerable larval fish populations. This will eventually decrease the adult populations in the hard bottom reef habitats.

This habitat is found on the continental shelf .Hard bottom reefs are areas of rock and ancient coral; places where the underlying rock sticks up through the sand. The hard surfaces provide structure to which sessile organisms, such as sponges and sea whips, attach themselves. Sessile organisms are animals that attach to a surface and remain there their entire lives. These sessile organisms cover hard bottom areas. The invertebrates found attached in this area include worm tubes, sponges, barnacles, and soft corals. Because they are in relatively shallow water, powerful storms such as hurricanes stir up the bottom in these areas and can bury these live bottom reefs in sand, as well as all the animals attached to them. Fish typical of this habitat are the grouper family; this fish has a long life expectancy and tends to remain in its preferred habitat, perhaps behaving territorially. Other typical fish of this ecosystem are snapper, black sea bass, barracuda, and rays.

Your challenge today is to create a real estate pamphlet that is geared towards one particular species of fish above. The pamphlet will describe a home (the type of habitat the fish is most likely to live in and thus, most likely to appeal to it), local restaurants and the food they serve (food that fish would eat), and nurseries that would be used by the young of the species (the places where the young of the species go to mature and why these places are beneficial to them). The location in the coastal waters of these habitats will be described. The last page of the pamphlet will be used to describe potential problems with the habitats you are describing. For adult fish habitats, describe things such as fishing pressures the fishes may have to deal with. Describe how many juveniles of the species use salt marshes as nursery grounds, explain how the water quality of the salt marsh they have will have on the nursery and potential sources of pollution that may be flowing in with the watershed.

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