Effects of tide pool volume on pool

diversityLindsay Grant, Anna Mairs, Charlotte Martin, Natalie Rideout and Gillian

Tetlow

The Rocky Intertidal – Tide Pools

• The coastal area that is exposed during low tide and submerged during high tide

• Contains a high biodiversity of species

• A receding tide leaves an accumulation of pools

Tide pools

• Allow organisms to escape high temperatures and desiccation

• Acts as breeding and nursing grounds, provides protection and a feeding habitat

• Can also be stressful environments • Changing ocean salinity, temperature and pH

Goal of Study

• To determine if the tide pool size affects the species diversity

• Hypothesis - Species abundance will increase with increased size and depth

of tide pools - However, species distribution will not be significantly different

between varying tide pool dimensions

Methods

• Sampled 10 random tide pools of different sizes• Measured dimensions

• Used a quadrat (1m x 1m) for larger pools

• Collected samples of all plants and animals present• Plant coverage estimated

• Identified all species in the lab http://vitalsignsme.org/sites/default/files/climatechange12012/049.jpg

Methods – Calculations

• Simpson’s Diversity Index: n = total number of organisms of a particular speciesN = total number of organisms of all species

Methods – Calculations

• Shannon-Wiener Diversity Index:

pi = proportion of total sample represented by species i

• H’max:

S = number of species

Results

• Plant average – 4.3

• 12 species total

• Animal average – 4.9

• 18 species total

Results

Results

Results

• No significant patterns found for plant or animal diversity

• More sparse species of animals found than plants

Discussion

Plants:

• 3 outliers

• Constant diversity irrespective of tide pool size

• Failed to support hypothesis

http://www.clarku.edu/departments/biology/biol201/2002/EMachala/Gallery.htm

Discussion

Animals:• Similar to plants, 2 outliers

• Richness vs Abundance

• Failed to support hypothesis

https://www.clarku.edu/departments/biology/biol201/2002/JDubois/Marine%20Gastropods.htm

Discussion

Confounding variables:

• Ambient conditions

• Elevation

• Uneven distribution of pool volumeshttp://www.acurite.com/7-5-thermometer-00338.html

Discussion

Supporting studies:• Cullity (2012)• Found no significant relationship

Biological relevance:• Metaxas and Scheibling (1993)• Refuge area from stressful conditions

Questions?