A study was conducted to determine if the diversity of marine species varied between high and low tides in tide pools at Hazard Canyon Reef. Random sampling was performed at both high and low tides using quadrats. The results showed that more species, on average, were observed at low tide compared to high tide, with average species counts of 11 at high tide and 21 at low tide. This is likely because more organisms get trapped in tide pools as the water level decreases at low tide.

1. Diversity of Marine Species in Tide Pools at Hazard Canyon Reef Between High and Low Tides
Jamie Binns, Neeka Gorgani, Jordan Nunes, and Tasha Taylor
Background:
Background
• What is a tide pool?
• Tide pools are formed when the tide rises then falls,
leaving seawater trapped in depression in the
surrounding terrain.
• There are four tidal zones: upper intertidal, mid-
intertidal, low intertidal, and sub-tidal. Only the upper
and mid-intertidal zones were sampled in this
experiment.
• How are tides formed?
• The tides are caused by the moon’s gravitational pull on
the ocean which causes bulges in the water.
• There are two different high tides and two different low
tides each day.
Question: Does the diversity of coastal organisms vary between
high tide and low tide?
Hypothesis: There is a difference in the diversity of species in tide
pools during high tide and low tide.
Prediction: The observed number of species in tide pools will be
greater during high tide than low tide.
Discussion:
• Based on the data collected, the original prediction was
not supported.
• This is because as the tide continues to lower, more and
more organisms get trapped and build-up within the tide
pool. At low tide, this build-up of organisms is at a max
until the tide starts coming in again.
• There was some human error that occurred during the
data collection.
Methods:
• A coordinate of 35*17*22N 120*52*59W was placed at Hazard
Canyon Reef in Montana de Oro State Park
• This coordinate was the origin of an x-y axis which was
measured out 10 m in each direction
• Ten points were generated from a random numbers table and a
PVC pipe quadrat was placed at each point
• Species were counted at each point and recorded
• This process was repeated at both high tide and low tide
• High Tide: 5.5 feet
• Low Tide: 0.2 feet
Results:
• There was a significant difference in the species observed
during high and low tides such that there was a greater
average number of species observed within each quadrat
sample during low tide compared to high tide.
(t = -3, df = 13.235, p-value < 0.05)
• Alpha Diversity
• High Tide: 11
• Low Tide: 21
• Beta Diversity: 17
Literature Cited:
• “Tides.” Explained. N.p., n.d. Web. 28 Nov. 2015.
• “Tidal Zones.” Oregon Tidepools. Oregon State Parks, 2012-2014. Web.
• “Tides and Water Levels.” NOAA National Ocean Service Education: National
Oceanic and Atmospheric Administration, 6 Oct. 2015. Web.
• “What is a Tide Pool?” SeaWorld Parks & Entertainment. SeaWorld Parks &
Entertainment, 2015. Web.