A rapid biodiversity assessment methodology tested on intertidal rocky shores

Abstract

ABSTRACT1. Conservation managers require biodiversity assessment tools to estimate the impact of human activities on biodiversity and to prioritize resources for habitat protection or restoration. Large-scale programs have been developed for freshwater ecosystems which grade sites by comparing measured versus expected species richness. These models have been applied successfully to habitats that suffer from systemic pressures, such as poor water quality. However, pressures in other habitats, such as rocky intertidal shores, are known to induce more subtle changes in community composition.2. This paper tests a biodiversity assessment methodology that uses the ANOSIM R statistic to quantify the biological dissimilarity between a site being assessed and a series of reference sites selected on the basis of their similar environmental profile. Sites with high R values for assemblage composition have an anomalous assemblage for their environmental profile and are potentially disturbed.3. This methodology successfully identified moderate to heavily perturbed sites in a pilot study on 65 rocky intertidal sites in south-eastern Australia. In general, measures based on percentage cover (flora and sessile invertebrates) were more sensitive than abundance (fauna).

Geodiversity inclusiveness in biodiversity assessment

“…Net methods were also varied and included sweep nets (Angélibert et al, 2010; Muelelwa et al, 2010), dip nets (Sewell et al, 2010), surber nets (Li et al, 2013) and others. Many scholars also adopted more traditional observation-based approaches (Ledo et al, 2012; Smith and Fisher, 2009; Tichit et al, 2010) and transect and quadrat methods (Geml et al, 2009; Gibson, 2011; Malik et al, 2019; O’hara et al, 2010). Infrequent approaches included snorkelling, scuba diving, Winkler bags and soil cores (Fig S1).…”

“…Marine (Arvanitidis et al, 2005; Zhan et al, 2014), forest (Lindqvist et al, 2016; Schulze et al, 2020) and aquatic environments (Alam et al, 2020; Hammer et al, 2014) were also frequently used (Figure 3). Coastal environments were one of the least common environment-types (Arvanitidis et al, 2005; Castro et al, 2021; O’hara et al, 2010).…”

Measures of taxonomic distinctness do not reliably assess anthropogenic impacts on intertidal mollusc communities

“…Gradients of temperature and exposure are known to occur along the Victorian coast (O'Hara 2001). We selected a number of environmental parameters across the coast including mean sea surface temperature, oceanographic variables (primary production, salinity, phosphate, nitrate and oxygen) wave power (a combined measure of wave height and wave period), rock hardness (measured on Moh's scale), surrounding rock area (within 1 and 10 km), aspect (perpendicular angle to the shoreline), reef type (boulder reef or flat rock platform), coastal type (bay or open coast) and latitude and longitude (Costa 2009, O'Hara et al 2010. Pearson correlation was used to examine the relationship between these environmental factors (hereafter macrofactors) and taxonomic distinctness at 60 sites along the coast (3 sewage sites were omitted).…”