Lawrencetown Beach Case Study

Rocky intertidal zonation at Lawrencetown Beach

Introduction
Nova Scotia has an extensive coastline with varying degrees of exposure. The intertidal zone (littoral zone) is where the ocean meets land and around Nova Scotia’s coast this zone is highly diverse, from salt marshes to mudflats and rocky shores. The intertidal zone is the area that is exposed to air at low tide and submerged by water at high tide and the species that are located here need to tolerate various levels of exposure. The factors that affect the abundance of species present in an area vary with spatial scale. Abiotic factors include rockiness, temperature, tidal influences, salinity, while biotic factors impacting an area. Biotic factors such as predation and herbivory …show more content…
• The Shannon diversity index (H) was applied to the collected data (Equation 1 and Sample calculation 1).

Equation 1:

Shannon diversity index (H):

Results

Table 1: Collected species data at Lawrencetown Beach starting at highest tide point (Group 1)
Quadrant (m)
Distance from shore Species Percent Coverage (%) Heterogeneity Tidal zone
0 Chondrus crispus
Laminaria saccharina
Nucella lapillus
Scytosiphon lomentaria
Fucus disitichus
Orchestia agilis 0.75
0.60
0.50
0.50
0.25
0.25 0.746 Supralittoral
2 Fucus vesiculosus
Littorina littorea
Carcinus meanas
Balanus balanoides
Mytilus edilus
Nucella lapillus
Ulva intestinalis
Ulva lactuca
Chondrus crispus
Acmaea testudinalis Orchestia agilis 40
3
3
1
1
0.50
0.40
0.25
0.25
0.25
0.25 0.375 Supralittoral
4 Fucus vesiculosus
Littorina littorea
Balanus balanoides
Carcinus meanas
Nucella lapillus
Ulva intestinalis
Orchestia agilis
Chondrus crispus 50
8
6
2
1
0.40
0.25
0.25 0.404 Supralittoral
6 Fucus vesiculosus
Littorina littorea
Balanus balanoides
Ulva intestinalis
Orchestia agilis
Mytilus edilus
Carcinus meanas
Nucella lapillus
Chondrus crispus
Nematoda 25
10 …show more content…
Algal fucoid species such as bladderwrack (Fucus vesiculosus), brown algae (Fucus disitichus) were the most abundant species present, followed by animal species such as barnacles (Balanus balanoides), sand fleas (Orchestia agilis) and periwinkles (Littorina littorea).
Normally barnacles (Balanus balanoides) dominate the supra-littoral mussels dominate the mid-littoral and infra-littoral zone exposed to wave action (Pederson et al., 2000; Hunt and Scheibling, 1995). However, sheltered shores such as Lawrencetown Beach exhibit more algal fucoid growth in the supra-littoral zone followed by Irish moss (Chondrus crispus) in mid-littoral zone (Blaxter and Southward, 1987). There was less Irish moss observed at the site sampled than that mentioned in the