The Effect of Temperature and Salinity on Abundance and Biodiversity at Tidepools of Puako, Hawaii

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1 Kojima 1 Caylin Kojima The Effect of Temperature and Salinity on Abundance and Biodiversity at Tidepools of Puako, Hawaii Background: The gravitational pull of the moon, sun, and Earth interact. The oceans, being fluid, can actually be pulled toward the moon. This creates the tide. The Earth itself is also pulled toward the moon. The ocean is stretched thin by this pull. High tides are in line with the moon while low tides are perpendicular to it. When the sun and moon are in alignment, the sun enhances the moon s gravitational pull, creating higher than normal tides (spring tides). When at a right angle to the moon, the sun diminishes the moon s pull, creating lower than normal tides (neap tides). Because of the movement of both the moon and Earth, there is a constant movement from high tide to low tide. Tidepools are puddles of area left when the tide recedes, typically found on rocky coastlines. They vary in shape and size. The environment in tidepools constantly changes due to being cut off from ocean water. Salinity is the saltiness or dissolved content of a body of water. It is an important parameter for living systems due to its effect on the chemistry of natural waters and the biological processes within it. This both limits and defines the ecosystem in which specific organisms can live. Temperature is also an important parameter for living systems as it, like salinity, limits and defines which organisms can and cannot survive in the affected ecosystem. Additionally, temperature impacts the availability of dissolved materials for living systems. Methods: Materials Hach multimeter Hawai`i's Sea Creatures: A Guide to Hawai`i's Marine Invertebrates by John P. Hoover Rope (1 m length) Cameras Sample bottles Distilled water Procedure 1) Select 3 tidepools of varying distance from the shore 2) Estimate & record number of strides from tidepool to shore 3) Use sample bottle to collect water from tidepool 4) Using multimeter to measure & record temperature and salinity (rinse with distilled water between samples) 5) Tie rope into hoop

2 Results: Kojima 2 6) Place gently onto surface of water 7) Count and identify (with guide) organisms within sample size/parameters of rope 8) Repeat with number of trials allowed by tidepool size Table 1. Tidepool Data Tidepool Location (strides from shore) Salinity (ppt) Temperature (F) A B C Table 2. Number of critters per unit area (abundance) Tidepool Sample One Sample Two A B 97 - C 64 - Table 3. Number of types of critters per unit area (biodiversity) Tidepool Sample One Sample Two A 6 B 4 C 3 Tripeneustes gratilla Echinometra lucunter Ophiocoma erinaceus Calcinus laevimanus Calcinus seurati Gobiidae Calcinus laevimanus Brachidontes crebristriatus Nerita polita Grapsus tenuicrustatus 6 Calcinus laevimanus Tripeneustes gratilla Echinometra lucunter Purse scallop (?) Haumea juddi - -

3 Kojima Salinity (ppt) 1 5 Tidepool C Figure 1. Average salinity for all tidepools Temperature (F) Tidepool C (5.5 ppt) Figure 2. Average temperature for all tidepools

4 Kojima Number of organisms per unit area 2 Tidepool C (5.5 ppt) Figure 3. Average abundance in all tidepools Number of types of organisms per unit area 1 Tidepool C (5.5 ppt) Figure 4. Average biodiversity in all tidepools

5 Kojima 5 Discussion The further from shore the tidepool was, the smaller it was in dimension and volume. was closest to the ocean and by far the largest (15x15 strides), was smaller in size (1x1 strides), and Tidepool C, furthest from the shore, was the smallest (4x4 strides). was closest to shore and therefore higher in salinity. Because of its proximity to the ocean, the ecosystem was relatively similar to that of the ocean, much more than those of B and C (5.5 ppt), which were greater distances away. Further from the ocean, tidepools receive water from a freshwater source. With greater exposure to the sun and no source of cold seawater at low-tide, tidepool temperature increases as you get further from shore., while having the highest salinity, had an average abundance of critters and 6 types of critters per unit area. with a lower salinity hosted 4 types of organisms with an abundance of 97. Lastly, Tidepool C had an extremely low level of salinity (5.5 ppt) with an abundance of 64 and a biodiversity count of 3 types of organisms. As distance from shore increases, salinity decreases and temperature increases. Higher salinity and lower temperatures allows for higher abundance and biodiversity in the tidepool.