We wanted to see if the north side of the Waipuilani tide pool has more marine life than south side the Waipuilani tide pool. Waipuilani tide pool is located in a lower inter-tidal zone between the upper inter-tidal zone and the sub-tidal zone on the coast of South Maui in Hawaii. An intertidal zone is the area of a coast that is always submerged by water except during very low tides. It is a tropical coastal habitat not subject to erosion because it is all rocky. Both the areas we observed are close to each other but are very different. The south side has many shallow pools and slightly exposed rocks and is buffered from wave action. The north side has no pools and harsher waves that break on the rocks. We are doing this study because the inter-tidal zone plays an import role in both the land and sea food chains. Without the marine life in these tide pools, many of the unique species in Hawaii would not exist. Marine creatures in this zone would need to be able to adapt to the higher temperature of the water and a higher concentration of salinity, some would need to be able to breathe above water. Without marine life in this zone, many creatures we see today would not be able to survive. For example, when the tide is in fish feed in this area, when the tide is out seabirds feed in this area. The animals that remain in this zone do not have to leave and they feed on each other or algae that grows there. A study has been done by The Ecology and Evolutionary Biology Department of The University of California in Santa Cruz (Carolyn Kurle 2003). In this study, scientists studied marine life on Rat Island in the Aleutian Islands in Alaska. They found that the inter-tidal zone was damaged by rats who ate the herbivores that kept the algae under control. As a result, there was a huge over growth of algae in this area. Another study has been done by The Zoology Department and Hawaii institute of Marine Biology of the University of Hawaii (Jill P. Zamzow 2003). In this study researchers gathered fish from different areas of the inter-tidal zone to examine their mucus. They found that fish with thicker mucus were able to withstand a harsher environment and more solar radiation than the fish in other areas with less mucus.

Our question was what area has more marine life in the same inter-tidal zone?

Our hypothesis is that the south side of the inter-tidal zone will have more marine life than the north side because the north is more exposed to harsher waves and stronger tides. We predicted that both zones will be covered by water most of the time except for very low tides and for creatures to live there they would have to be able to either swim father out to sea or survive exposure to air.

The results for both the samples were taken on 9/12/07, the weather was partly cloudy, the air temperature (28ºC) the water temperature was 1 º C in difference (25º C and 26 º C). The salinity was also the same at 35 PPT. We found that there were 27 crabs in the north tide pool. We found that in the south tide pool there were 9 crabs. So there were 3 times as many crabs in the north tide pool than in the south tide pool. We also found that there was 1 snail in the north tide pool and none in the south tide pool. We found that in the north tide pool there were 0 fish and in the south tide pool there were 3 fish.

Our goal was to find out what side of the tide pools has more life, the north side or the south side. We did this study because the inter-tidal zone is an important area in the food web and we wanted to know how much marine life was in the tide pools and in which part. We found that there was more total marine life on the north side (zone 2) of the tide pools than on the south side (zone 1). This means that our hypothesis was wrong and that sea life survives better with harsher waves. Maybe this is because the shallow pools are exposed longer during low tide and some animals have trouble surviving. We also found that all the marine life on the north side were invertebrates with a protective shell. The current and harsh waves might have made it harder for fish live in this part of the lower inter- tidal zone while crabs and snails could get food easier. Our possible sources of error might have been that we did not turn over enough rocks to find what was beneath them so the actual amount was not counted correctly. Another possible source of error is that the temperature was not the same for each area so certain creatures might not have been there. Another study done by marine science writer Susan Scott in 2001 reported ghost crabs (Ocypode pallidula) are scavengers and often found in locations where there is a lot of wave activity that brings in food, perhaps we found more crabs on the north side because of the wave activity.
(Left to right from upper-left, Zone 1-South Side, Total Marine Life Counted, Zone 2-North side, Total Marine Life)