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During our first trip to an intertidal site we laid out transects and used quadrats to estimate the percentage cover of species found in a given area. After taking data on about 30 meters we were free to collect as many species as we could. Some of the supplies we brought along were buckets, containers, plastic bags, gloves, tweezers, tongs, and field guides. We would collect species using nets or our hands, and carefully place them in buckets. Then we would identify each species one by one using a field guide and record our findings in data tables. If we were not able to identify a species, we brought it back to class with us. We also recorded information about species we found in our notebooks. The notebooks include a description of the site, all the species we found, information about those species, and a species list. We also entered this data into a computer.

Site descriptions:

Diamond Head. February 18, 2004. Diamond Head was rocky with two foot waves. It was hot, with clear skies, making it easy to search for organisms. There was a lot of algae and rocks. The rocks were flat and it was very slippery.

Kahana Bay. March 9, 2004. It was really windy, rainy, and cold. The water was dirty, so it was hard to see in the water. There was hardly any sand and there were lots of rocks. When we got there the tide was low, but as time went on, it began to rise.

Coconut Island. April 2, 2004. Very rainy and cloudy. Because of the rainy weather, the trip was cut short, and we didn’t find as many species as last year.

Sandy Beach. April 6, 2004. Very hot and sticky. It was very sandy with lots of rocks. It was windy, and there were small waves (non-affected). The water was about knee-deep. There were a lot of boulders covered with algae.

Ewa Beach. April 22, 2004. When we arrived it was sunny, but then it got cloudy. There were not many rocks. It was mostly reef, coral rock and sand, and a lot of algae. The tide went up at the end of the trip. There were lots of tidepools and one area where it looked like someone made a fishpond.

Shark’s Cove. May 8, 2004. It was very rocky. The water was clear and it was windy. It was like a big tidepool with a drop-off close to the middle. Close to the rock wall was a lot of sand. Crabs were most commonly found.

Threats to the Intertidal:

Some threats to the Intertidal include pollution. If people throw trash and it gets into the intertidal, it dirties the water and kills plants and animals. Things like sewage spills and oil spills damage the habitat of the intertidal animals. Invasive species are also threats to the intertidal because they endanger native and endemic species. They compete for food and space and they could kill off the native species. Habitat destruction is harmful because people could break off coral and shells, which could be home for animals. Sometimes these animals may not be able to find other homes.

Pollution is a threat to the intertidal because it can make many of the animals that live in the intertidal sick. What if some of the species that had gotten sick and died out was a food resource for another animal? Then it will start a chain reaction and many animals might die out. Global warming is a threat to the intertidal because the temperature around us will rise so that the water temperature might rise and some organisms can’t live in certain water temperatures so they will die out. That will probably change the food chain so other species’ populations will either increase or decrease. There will also be more rain because of the temperature increase, so the water level could rise and the salinity of the water drop. If the water level rises on shore will drown and others will start growing higher up shore. Some organisms can’t survive if the water gets less salty and fresher so it will kill them if the salinity decreases.

The threats to the intertidal are things like pollution. Pollution affects the intertidal because the pollution in streams and rivers empty directly into the intertidal. Every thing that is put into a stream up in the mountains eventually runs down into the ocean. The first place it hits is the intertidal. Another thing that is a threat to the intertidal is invasive species. Invasive species can kill all of the native species. The native species might also form a symbiosis with the invasive species. This could result in a stronger bond between the two species or it could result in the creation of a hybrid species if the native and invasive species were to mate. Invasive species could affect the population and the amount of different species in the intertidal. The third thing that is a threat to the intertidal is global warming. Global warming causes either the rising or the evaporation of the water in the intertidal. The species that need little water will die when the water level rises. When the water level lowers, the species that need a lot of water will die. There are many things that affect the intertidal. We all need to be aware of our surroundings and what do. We need to know where we put our garbage and what we put into the atmosphere.

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