2022-04-12-P&E Agenda - Item 6 - Attachment 3- Appendix 2 - Current and Historical Distribution of Seagrass in the Noosa Estuary

                                                            Ecological Service Professionals
                                                                               Sustainable Science Solutions




2 Methods

2.1 Study Area
The Noosa River catchment has its headwaters in the Cooloola section of the Great Sandy
National Park. There are several main tributaries, and the main river flows through several
shallow lakes, and along a main river channel to the ocean.
The study area for this assessment covered a substantial section of the estuarine habitat in
the Noosa Estuary and lakes, including both intertidal and subtidal zones with the most
upstream extent in Lake Cooroibah (designated as the upper extend of seagrass distribution)
to the mouth of the estuary; and upstream in Weyba Creek to Lake Weyba (Figure 2.1). The
estuary was separated into seven reaches including:
1) Lake Cooroibah (and the main Noosa River channel upstream of the vehicle ferry);
2) Noosa River from Tewantin to the vehicle ferry;
3) Noosa River around Goat Island and downstream;
4) Noosa River mouth and Noosa Sound;
5) Lake Doonella;
6)Weyba Creek; and,
7) Lake Weyba (Figure 2.1).

2.2 Desktop Review and Initial Mapping
An initial desktop review and gap analysis of existing information available on the distribution
and condition of seagrass in the Noosa River Estuary, including spatial data sets, was
completed. Prior surveys and aerial imagery were used to complete an initial broadscale
seagrass and marine habitat map of the study area, based on experienced visual
interpretation of available aerial and satellite imagery and publicly available GIS spatial
layers. This map was used to prioritise specific focal areas for more detailed field validation
and seagrass characterisation (Section 2.3 below).

2.3 Field Surveys
The survey was completed over four days (3 to 5 November 2020 and 8 December 2020)
using a combination of remote techniques from a vessel (including ROV, tow camera and
drop cameras), and visual assessments on foot at low tide (where possible) to identify the
condition and presence of seagrass. Where visibility was low (due to turbidity of waters), spot
snorkel surveys and a small grapple hook were used to confirm the presence of seagrass,
where it was safe to do so and following a strict risk assessment protocol. Detailed methods
are described in Sections 2.3.1 to 2.3.3 below.
The work was completed under a QLD General Fisheries Permit (208641) issued to ESP and
an accepted development application (received 07/09/2020), for the collection and limited
disturbance of marine plants in a fish habitat area where voucher samples were required for
field verification and identification.

Assessing Distribution of Seagrass in the Noosa Estuary                                                   3