About the Biounit
The Fowlers Biounit is located in the Murat bioregion and is the western most biounit monitored in the EPA’s nearshore marine program. The biounit spans from Cape Adieu in the West to Point James near Davenport creek west of Ceduna.
Fowlers’ experiences high wave energy along the rocky limestone coast with headlands jutting into the sea and isolated sandy beaches. In the lee of the rocky headlands there are small relatively sheltered bays. The rocky headlands and reefs support diverse brown and red macroalgal communities, while in the lee of the rocky headlands, seagrasses can thrive particularly Posidonia spp. and Amphibolis spp.
The adjacent land use is primarily cereal and modified pasture crops and there are areas of coastal conservation park. There are few permanent residents in Fowlers, but what dwellings there are, would treat sewage via on-site septic tanks. There is a large saltfield near Penong, at Lake McDonnell, which evaporates seawater to harvest salt. The evaporation encompasses the bitterns waste, which results in no discharge to the marine environment.
In summary
There was only 1 site monitored in 2019. This site showed that seagrass habitat was dense and intact with very little epiphytes and the reef parts of the site was comprised of large dense brown canopy algae with diverse communities of red algae. This suggested the reef was in very good condition and has not changed since the 2014 survey.
Findings
The condition of habitats in waters between 2–15 m deep throughout the Fowlers biounit was assessed based on monitoring data collected during autumn 2019. The score classifies sites on the ecological condition based on habitat integrity outlined in the methods report.
Site
|
2019
|
Condition
|
Trend
|
m0449, East of Pt. Bell
|
Very Good
|
 |
East of Pt. Bell (m0449) is in a high energy environment where waves and currents shift sand around the base of the reef. The reef and seagrass habitats are taken into account when determining condition. The seagrass parts of the site were typically dense Posidonia seagrass with some Amphibolis sp. interspersed with the reef, there was typically very low epiphytes over the seagrass. The reef sections of the site were typified by the canopy algal species Sargassum, Phyllospora and Ecklonia, with understorey of large red algae such as Osmundaria porifera suggesting the reef was in good condition. It is likely that the apparent increase in reef cover, and reduction in seagrass cover from 2014 to 2019 are a result of the sand movement across the site and do not represent a change in condition. Amphibolis sp. seagrass can settle and grow on reef habitats where there is sufficient overlying sand allowing root establishment. Seagrasses trap sand allowing for further growth and cover of the benthos. Future monitoring of m0449 may show further changes due to the oceanic conditions.
Pressures and management responses
There are no known pressures acting on the Fowlers Nearshore Marine Biounit. This area of marine environment is considered to be unimpacted by human activities. As such, management responses have also not been established for this biounit.
Further information
- Download the Methods Report for the nearshore marine ecosystems monitoring, evaluation and reporting program.
Detailed statistical analysis
These pages outline the statistical analysis undertaken for the Fowlers Biounit. It should be read in conjunction with the AECR for that biounit. The methods used for the collection of the information can be found detailed in marine methods.
There were insufficient sites to undertake a principal coordinate analysis (PCO) so analysis has been limited to site based comparisons. The habitat variables; total seagrass cover, bare sand, epiphyte and opportunistic algae were used to compare the site over the years it was monitored using Primer v7 and PERMANOVA add-on[1]. The data was square root transformed and all transects in a site were used in the analysis. Pairwise comparisons were used to determine whether the site was different between years (Table 1).
East of Pt. Bell (m0449) is in a high energy environment where waves and currents shift sand around the base of the reef. The seagrass parts of the site were typically dense Posidonia seagrass with some Amphibolis sp. interspersed with the reef, there was typically very low epiphytes over the seagrass. The reef sections of the site were typified by the canopy algal species Sargassum, Phyllospora and Ecklonia, with understorey of large red algae such as Osmundaria porifera suggesting the reef was in good condition. It is likely that the apparent increase in reef cover, and reduction in seagrass cover from 2014 to 2019 are a result of the sand movement across the site and do not represent a change in condition. Amphibolis sp. seagrass can settle and grow on reef habitats where there is sufficient overlying sand allowing root establishment[2]. The low Fp ratio and the size class of phytoplankton are consistent with a low nutrient environment (Figures 2 and 3).
Table 1 Pairwise comparisons for the site was performed using fixed effects on sqrt transformed 2014 and 2019 habitat data for all sites in Fowlers after generating resemblances using Bray–Curtis similarities. In order to be conservative p values of less than 0.01 were considered significant.
Site
|
Pairwise tests
|
m0449
|
Groups
|
t
|
P(perm)
|
2014, 2019
|
2.0758
|
0.0207
|
|

Figure 1 Benthic habitat composition at m0449 in the Fowlers Biounit in 2019.

Figure 2 Fp ratios for the site in Fowlers in 2019. Oligotrophic conditions are considered to have an Fp ratio less than 0.3, mesotrophic conditions are above 0.3 and less than 0.7, and eutrophic conditions are signified by an Fp ratio above 0.7.

Figure 3 Size class categories of phytoplankton communities in Fowlers Biounit in 2019.
While the AECR score is developed from a set of metrics outlined in the Methods document. This document outlines the key information used and additional statistical analysis undertaken to interpret the results of the AECR for these sites. It provides the confidence that the AECR score is consistent with the scientific interpretation and attempts to understand the pressures acting on the system.
This document does not outline all data collected for this program, additional data (eg: water chemistry) can be downloaded on the download data tab on the website or by contacting the EPA.
[1] Anderson, M., Gorley, R. and Clarke, R. (2008) Permanova+ for Primer: Guide to Software and Statistical Methods. Plymouth, UK.: Primer-E Ltd.
[2] Pocklington, J. (2012). Amphibolis antarctica. Sea Nymph in Museums Victoria Collections, accessed 11 May 2020.