Effects of Physical Dimensions on Tide Pool Diversity

Jessica Allen, Celine Morais, Hilary Mann, Erika McLellan, and Sydney Bliss

Tide Pool - Community Structure

Species differ in diversity and abundance between the rocky intertidal and tide pools, largely due to the physical and biological regimes of each

Fluctuation of physical factors is smaller in tide pools that the general intertidal (allowing vertical ranges of species to extend higher)

Conversely, biological interactions (ex. grazing and predation) are intensified in tide pools

Communities are often patchy and somewhat unpredictable

Some species are residents, some and transients, some are accidental visitors

There are strong associations between a pool’s physical size and its community structure

Tide Pools – Physical Factors

Main factor dictating species diversity in a tide pool

Ex. temperature, salinity, wave and splash exposure, degree of shading, volume

The intensity of these is largely dictated by pool shape and depth

Fluctuate vertically, horizontally, diurnally and seasonally

Thus, each pool has a unique physical regime that largely determines community structure

Many studies have shown that the number of species present in a pool is associated with pool depth and volume

Ex. deeper pools may support more plant and invertebrate species

Our study attempted determine if the physical dimensions of a tide pool affect the diversity of organisms within it, as previous studies have

Null hypothesis = the physical dimensions of a tide pool have no affect on species diversity within them

Alternate hypothesis = the physical dimensions of a tide pool have an affect on species diversity within them

Methods

Measuring abiotic factors

Sampled and recorded species within quadrates or entire tide pool

Species were collected for identification

Results

Figure 1. The effect of tide pool size on diversity at a) Indian Point and b) Green’s Point.

Discussion

Ho: Physical dimensions of the tide pools would have no effect on the species diversity found within these pools

Metaxas and Scheibling, 1993; Mahon and Mahon, 1994 Area, volume, and species diversity

Factors that could explain discrepancies in the findings

Cold weather

Season

Sample size

Wave action and intertidal profile

Size of tide pools sampled

Omitted depths of tide pools from our calculations

Future Studies

Larger sample sizes More time needed

Greater range of tide pools

Sampling at more locations

Accurate methods of measurement Salinity and Oxygen

Gather information at different times of day and seasons Limited due to tides