Coastal Ecosystems
There are five coastal ecosystems that can be found around the islands in the Galapagos Archipelago: rocky shores, vertical rock walls, sandy beaches, mangroves, and coral reefs (Wellington 1995).
Rocky Shores:
This ecosystem varies through the islands due to differences in exposure and waves, but mainly has tidal fluctuations of less than 3 meters (Wellington 1995).
The rocky surface supports algal grazers like grapsoid crabs, marine iguanas, chitons, and neritid gastropods. As you move into the lower intertidal/subtidal zone, you find sea anemones, sea fans, urchins, surgeonfish, large schools of parrotfish, green turtles, and marine iguanas. In shallow water you will find damselfish coexisting with algal gardens. On the subtidal rock there are sessile gastropods, including Hipponix pilosus, the most common invertebrate. Planktivorous fishes also live here, which are the source of food for blue-footed boobies, flightless cormorants, and the Galapagos penguins. These fishes also attract sharks like the Galapagos shark, the white-tip shark, and the hammerhead shark (Wellington 1995).
Vertical Rock Walls:
In these ecosystems live sponges, tube worms, ascidians, bryozoans, and some hydroids and ahermatypic corals An interesting thing to note-black coral are found here but are being exploited. They grow slowly, so are not surviving the exploitation very well (Wellington 1995).
Sandy Beaches:
Here the sediment is composede of carbonate and tufa. The scavenging ghost and hermit crabs live in this ecosystem, as well as sand dollars and burrowing anemones. This ecosystem has a very high amount of endemic species, but little research has been done in this environment (Wellington 1995).
Mangroves:
Four types of mangroves exist in the Galapagos: red mangroves, black mangroves, white mangroves, button mangroves. This habitat supports red algae, gastropods, fiddler crabs, green turtles, bat rays, and snooks (Wellington 1995).
Coral Reefs:
Massive species of coral are allowed to develop due to a symbiosis with damselfish, who eject urchins (Wellington 1995). For more info, see the coral page.
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