Current position of the SSV Corwith Cramer. Click on the vessel to view position history. Use the tools, top right, to change the map style or view data layers. Dates and times use GMT (Greenwich Mean Time).
SEA Currents: SSV Corwith Cramer
June 07, 2015
Field Trip to Waimanalo Beach
Today we embarked on our second field trip of our SEA Semester program. After heading into the field and getting our hands dirty by taking measurements of a stream in Waimea Valley yesterday, I was super excited to see what this day had in store for us. On top of everything, today was actually my birthday, which made me that much more excited! We went to Waimanalo Beach on the island of O'ahu to explore an example of the island's coral reef ecosystem. Once there, our TA Catherine sat us down on the edge of a gorgeous looking beach with crystal clear blue water to explain to us the basics of a coral reef ecosystem.
We learned about all the elements of your typical coral reef ecosystem: fish, crustaceans, sea urchins, sponges, invertebrates, plankton - both zooplankton and phytoplankton, the sun (which everyone commonly overlooks) and most importantly the coral itself. Corals provide structure to the surrounding areas and are the habitat that a wide variety of sea life call home. Such structures populate areas in large colonies and have several different forms such as antler coral, branched coral, brain coral, and tabletop coral. Interestingly, coral are actually closely related to sea anemones and can even give you a slight sting if touched. Coral reproduce sexually or asexually via polyps, which can take "root" in an area during sexual reproduction or produce buds that are exact clone copies of the parent during asexual reproduction. These polyps secrete calcium carbonate in such a way that it forms a sort of skeleton around them and this is the rigid structure we imagine when we think of coral. In order to feed, coral can catch other smaller organisms in the filaments of their polyps or through an endosymbiotic relationship that they have with zooxanthellae, a special photosynthetic microorganism that is housed within the polyp itself, which can provide nutrients to the coral. Fun fact: these zooxanthellae are what give each species of coral its color!
We also learned that coral like to live in warm waters in the photic zone of the ocean where sunlight is still able to penetrate the water enough for their zooxanthellae to still photosynthesize. However, if conditions become too stressful for the coral, lets say in the case of rising ocean temperatures (*cough, cough* global warming *cough, cough*), the coral will actually expel their little buddies and become bare and colorless, this is called coral bleaching. If situations such as this continue, the coral will basically starve because they aren't able to acquire enough nutrients.
After learning all about these coral ecosystems we got to hop in the water with all of our snorkeling gear and explore the Waimanalo reef, after the requisite safety lecture of course. It was absolutely beautiful!! We saw so many types of fish such as the trumpetfish, the needlefish, puffer fish, and even the state fish: the reef triggerfish aka Humuhumu-nukunuku-apua'a! Say that five times fast! In the end, I had a wonderful birthday, with wonderful people, in an absolutely stunning area of paradise