Investigation into the effects of high versus low wave exposure on species diversity and community structure in the rocky intertidal coast of the Passamaquoddy Bay BIOL-3361 Emily Byrne, Quentin Heffell, Kevin Isherwood, Leah McCredie, Jonathan O’Keefe

Introduction What are wave exposed coastlines?

Introduction Impact of wave exposure on species size Age as a function of wave exposure Wave exposure and competition

Kelp forest macrofauna Kjeil Magnus Noderhaug et al. 2012 Disturbance from wave surge is important for faunal diversity and community structure.

Balentine Scale

Hypothesis Areas of low wave exposure, species richness and diversity will suffer relative to high wave exposure sites Related to reduction in competition as a result of increased mechanical stress

Passamaquoddy Bay

Indian Point

Green’s Point Low wave exposure site High wave exposure site

Methods Sampling of 10 quadrats along a line transect Species counts recorded Unknown species collected for identification

Data Analysis Data from across quadrats were pooled Indian Point Marine Gastropods Cirripedia Statistical tests Simpson’s Diversity Index Shannon- Weiner Diversity Index T-test Sorrenson’s Similarity Index

Results 37 species identified 11 found at all 4 sub-sites

Results

Indian Point 19 species identified

Green Point 29 species identified

Discussion Sub sites are not statistically different in terms of diversity at both locations Results consistent with Balantine scale Sampling error Future investigations? Reiterate hypothesis: assumed that due to the intermediate disturbance hypothesis higher species diversity would be found in areas of higher wave exposure when compared to low wave exposure as monocultures of overbearing species could not be established HAS BEEN FOUND BEFORE :(Gibbons, 1988). It was found that Gelidium populations occupying exposed shores were flushed away easier than those in sheltered habitats. Water turbulence and the battering effects of wave action are contributors to species mortality, lowering richness in exposed areas (Vadas et al., 1990). Results, however, did not support this hypothesis in that no statistically significant differences were noted between the sub-sites Community structure was, however, in accordance with previous literature - Ascophyllum found more abundantly in low wave exposed sites - Cirripedia found more abundantly in exposed sites (algal turn not established) - Littorena obtusa, Littorena littoria, and Balanous balanous, were all found to be more abundant in low wave exposed sites, also consistent with Balletine’s results Error: - taxonomic classification (better knowledge would have allowed for the individual classification of barnacles and marine gastropods initially) - statistical analysis - sampling process (transects and quadrats may not be an accurate representation of species diversity in the sites) Future Investigations: - Effects of seasonality on species diversity and richness - Entirely possible that some species may only occupy the Pass. Bay during certain times of the year, of that species present may be in different abundances based on their individual breeding/life cycles - Having prior knowledge of this would have potentially explained the abundances of the species sampled - Would be interesting to sample in the same locations throughout the year to examine the effects of seasonal environmental variation - Exclusion cages of various grating sizes to examine establishment, competition, and successional patterns (destroy area and then examine how it is repopulated in areas of high wave exposure vs. low wave exposure)

Questions?