Wilson Inlet was surveyed in December 2017, April 2018, December 2019, December 2020, December 2021 and December 2022 by underwater drop camera observations and/or observations through a viewing cone. Seagrass distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intevals) and epiphytic cover (as low, medium, high) was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles, photosynthetically active radiation (euphotic depth), and secchi depth were recorded. The datasets making up the seagrass survey data are: Wilson_Seagrass - point dataset Wilson_Seagrass_Extent - polygon showing presence/absence derived from points Wilson_Seagrass_Cover - polygon showing percentage cover derived from points Layers: Wilson_Seagrass_Dec_2017 Wilson_Seagrass where Year = '2017' Wilson_Seagrass_Apr_2018 Wilson_Seagrass where Year = '2018' Wilson_Seagrass_Dec_2019 Wilson_Seagrass where Year = '2019' Wilson_Seagrass_Dec_2020 Wilson_Seagrass where Year = '2020' Wilson_Seagrass_Dec_2021 Wilson_Seagrass where Year = '2021' Wilson_Seagrass_Dec_2022 Wilson_Seagrass where Year = '2022' Wilson_Seagrass_Extent_Dec_2017 Wilson_Seagrass_Extent where Year = '2017' Wilson_Seagrass_Extent_Apr_2018 Wilson_Seagrass_Extent where Year = '2018' Wilson_Seagrass_Extent_Dec_2019 Wilson_Seagrass_Extent where Year = '2019' Wilson_Seagrass_Extent_Dec_2020 Wilson_Seagrass_Extent where Year = '2020' Wilson_Seagrass_Extent_Dec_2021 Wilson_Seagrass_Extent where Year = '2021' Wilson_Seagrass_Extent_Dec_2022 Wilson_Seagrass_Extent where Year = '2022' Wilson_Seagrass_Cover_Dec_2017 Wilson_Seagrass_Cover where Year = '2017' Wilson_Seagrass_Cover_Apr_2018 Wilson_Seagrass_Cover where Year = '2018' Wilson_Seagrass_Cover_Dec_2019 Wilson_Seagrass_Cover where Year = '2019' Wilson_Seagrass_Cover_Dec_2020 Wilson_Seagrass_Cover where Year = '2020' Wilson_Seagrass_Cover_Dec_2021 Wilson_Seagrass_Cover where Year = '2021' Wilson_Seagrass_Cover_Dec_2022 Wilson_Seagrass_Cover where Year = '2022'

Wilson Inlet was surveyed in December 2017, April 2018, December 2019, December 2020, December 2021 and December 2022 by underwater drop camera observations and/or observations through a viewing cone. Seagrass distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intevals) and epiphytic cover (as low, medium, high) was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles, photosynthetically active radiation (euphotic depth), and secchi depth were recorded. The datasets making up the seagrass survey data are: Wilson_Seagrass - point dataset Wilson_Seagrass_Extent - polygon showing presence/absence derived from points Wilson_Seagrass_Cover - polygon showing percentage cover derived from points Layers: Wilson_Seagrass_Dec_2017 Wilson_Seagrass where Year = '2017' Wilson_Seagrass_Apr_2018 Wilson_Seagrass where Year = '2018' Wilson_Seagrass_Dec_2019 Wilson_Seagrass where Year = '2019' Wilson_Seagrass_Dec_2020 Wilson_Seagrass where Year = '2020' Wilson_Seagrass_Dec_2021 Wilson_Seagrass where Year = '2021' Wilson_Seagrass_Dec_2022 Wilson_Seagrass where Year = '2022' Wilson_Seagrass_Extent_Dec_2017 Wilson_Seagrass_Extent where Year = '2017' Wilson_Seagrass_Extent_Apr_2018 Wilson_Seagrass_Extent where Year = '2018' Wilson_Seagrass_Extent_Dec_2019 Wilson_Seagrass_Extent where Year = '2019' Wilson_Seagrass_Extent_Dec_2020 Wilson_Seagrass_Extent where Year = '2020' Wilson_Seagrass_Extent_Dec_2021 Wilson_Seagrass_Extent where Year = '2021' Wilson_Seagrass_Extent_Dec_2022 Wilson_Seagrass_Extent where Year = '2022' Wilson_Seagrass_Cover_Dec_2017 Wilson_Seagrass_Cover where Year = '2017' Wilson_Seagrass_Cover_Apr_2018 Wilson_Seagrass_Cover where Year = '2018' Wilson_Seagrass_Cover_Dec_2019 Wilson_Seagrass_Cover where Year = '2019' Wilson_Seagrass_Cover_Dec_2020 Wilson_Seagrass_Cover where Year = '2020' Wilson_Seagrass_Cover_Dec_2021 Wilson_Seagrass_Cover where Year = '2021' Wilson_Seagrass_Cover_Dec_2022 Wilson_Seagrass_Cover where Year = '2022'

Hardy Inlet was surveyed by underwater drop camera observations in December 2018 and January 2020. Seagrass species distribution and cover (as percentage cover in categories: 0, 1-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intervals) and epiphytic cover (as low, medium, high) of seagrass was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 1-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles and secchi depth were recorded. The datasets making up the Hardy Inlet Seagrass Survey data are: Hardy_Seagrass - point dataset Hardy_Seagass_Extent - polygon showing presence/absence derived from points Hardy_Seagrass_Cover - polygon showing percentage cover derived from points Layers: Hardy_Seagrass_Dec_2018 - Hardy_seagrass points where Year = '2018' Hardy_Seagrass_Jan_2020 - Hardy_seagrass points where Year = '2020' Hardy_Seagrass_Extent_2018 - Hardy_Seagrass_Extent where Year = '2018' Hardy_Seagrass_Extent_Jan_2020 - Hardy_Seagrass_Extent where Year = '2020' Hardy_Seagrass_Cover_2018 - Hardy_Seagrass_Cover where Year = '2018' Hardy_Seagrass_Cover_Jan_2020 - Hardy_Seagrass_Cover where Year = '2020'

Hardy Inlet was surveyed by underwater drop camera observations in December 2018 and January 2020. Seagrass species distribution and cover (as percentage cover in categories: 0, 1-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intervals) and epiphytic cover (as low, medium, high) of seagrass was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 1-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles and secchi depth were recorded. The datasets making up the Hardy Inlet Seagrass Survey data are: Hardy_Seagrass - point dataset Hardy_Seagass_Extent - polygon showing presence/absence derived from points Hardy_Seagrass_Cover - polygon showing percentage cover derived from points Layers: Hardy_Seagrass_Dec_2018 - Hardy_seagrass points where Year = '2018' Hardy_Seagrass_Jan_2020 - Hardy_seagrass points where Year = '2020' Hardy_Seagrass_Extent_2018 - Hardy_Seagrass_Extent where Year = '2018' Hardy_Seagrass_Extent_Jan_2020 - Hardy_Seagrass_Extent where Year = '2020' Hardy_Seagrass_Cover_2018 - Hardy_Seagrass_Cover where Year = '2018' Hardy_Seagrass_Cover_Jan_2020 - Hardy_Seagrass_Cover where Year = '2020'

The Peel-Harvey Estuary was surveyed in March and April 2021 by underwater drop camera observations and/or observations through a viewing cone. Seagrass species distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intervals) and epiphytic cover (as low, medium, high) of seagrass was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles, photosynthetically active radiation (euphotic depth) and secchi depth were recorded. The datasets making up the Peel-Harvey Estuary Seagrass Survey data are: PeelHarvey_Seagrass - point dataset PeelHarvey_Seagass_Extent - polygon showing presence/absence derived from points PeelHarvey_Seagrass_Cover - polygon showing percentage cover derived from points Layers: PeelHarvey_Seagrass_Mar_2021 - PeelHarvey_seagrass points where Year = '2021' PeelHarvey_Seagrass_Extent_2021 - Hardy_Seagrass_Extent where Year = '2021' PeelHarvey_Seagrass_Cover_2021 - Hardy_Seagrass_Cover where Year = '2021'

Hardy Inlet was surveyed by underwater drop camera observations in December 2018 and January 2020. Seagrass species distribution and cover (as percentage cover in categories: 0, 1-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intervals) and epiphytic cover (as low, medium, high) of seagrass was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 1-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles and secchi depth were recorded. The datasets making up the Hardy Inlet Seagrass Survey data are: Hardy_Seagrass - point dataset Hardy_Seagass_Extent - polygon showing presence/absence derived from points Hardy_Seagrass_Cover - polygon showing percentage cover derived from points Layers: Hardy_Seagrass_Dec_2018 - Hardy_seagrass points where Year = '2018' Hardy_Seagrass_Jan_2020 - Hardy_seagrass points where Year = '2020' Hardy_Seagrass_Extent_2018 - Hardy_Seagrass_Extent where Year = '2018' Hardy_Seagrass_Extent_Jan_2020 - Hardy_Seagrass_Extent where Year = '2020' Hardy_Seagrass_Cover_2018 - Hardy_Seagrass_Cover where Year = '2018' Hardy_Seagrass_Cover_Jan_2020 - Hardy_Seagrass_Cover where Year = '2020'

The Peel-Harvey Estuary was surveyed in March and April 2021 by underwater drop camera observations and/or observations through a viewing cone. Seagrass species distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intervals) and epiphytic cover (as low, medium, high) of seagrass was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles, photosynthetically active radiation (euphotic depth) and secchi depth were recorded. The datasets making up the Peel-Harvey Estuary Seagrass Survey data are: PeelHarvey_Seagrass - point dataset PeelHarvey_Seagass_Extent - polygon showing presence/absence derived from points PeelHarvey_Seagrass_Cover - polygon showing percentage cover derived from points Layers: PeelHarvey_Seagrass_Mar_2021 - PeelHarvey_seagrass points where Year = '2021' PeelHarvey_Seagrass_Extent_2021 - Hardy_Seagrass_Extent where Year = '2021' PeelHarvey_Seagrass_Cover_2021 - Hardy_Seagrass_Cover where Year = '2021'

The Peel-Harvey Estuary was surveyed in March and April 2021 by underwater drop camera observations and/or observations through a viewing cone. Seagrass species distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. The canopy height (in 10 cm intervals) and epiphytic cover (as low, medium, high) of seagrass was also estimated. Macroalgae distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded. At approximately a third of the sites, physical water profiles, photosynthetically active radiation (euphotic depth) and secchi depth were recorded. The datasets making up the Peel-Harvey Estuary Seagrass Survey data are: PeelHarvey_Seagrass - point dataset PeelHarvey_Seagass_Extent - polygon showing presence/absence derived from points PeelHarvey_Seagrass_Cover - polygon showing percentage cover derived from points Layers: PeelHarvey_Seagrass_Mar_2021 - PeelHarvey_seagrass points where Year = '2021' PeelHarvey_Seagrass_Extent_2021 - Hardy_Seagrass_Extent where Year = '2021' PeelHarvey_Seagrass_Cover_2021 - Hardy_Seagrass_Cover where Year = '2021'

Leschenault Estuary was surveyed in April 2009, February 2015, February and March 2016, February 2017, February and March 2018, February 2019, February and March 2020, February 2021, February and March 2022, and February and March 2023. Seagrass species distribution and cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%), epiphytic cover (as none, low, medium or high) and macroalgae cover (as percentage cover in categories: 0, 0-10%, 10-25%, 25-50%, 50-75%, 75-90%, 90-100%) were recorded at each site. At approximately a third of the sites, physical water profiles, secchi depth and photosynthetically active radiation (euphotic depth) were conducted from 2018 onwards. When observation locations were inaccessible by boat, sites were accessed from kayaks paired with drone imagery which was used to make observations. The datasets making up the Leschenault seagrass survey data are: Leschenault_Seagrass - point dataset Leschenault_Seagass_Extent - polygon showing presence/absence derived from points Leschenault_Seagrass_Cover -polygon showing percentage cover derived from points Layers: Leschenault_Seagrass_Apr_2009 - Leschenault_Seagrass points where Year = '2009' Leschenault_Seagrass_Feb_2015 - Leschenault_Seagrass points where Year = '2015' Leschenault_Seagrass_Feb_2016 - Leschenault_Seagrass points where Year = '2016' Leschenault_Seagrass_Feb_2017 - Leschenault_Seagrass points where Year = '2017' Leschenault_Seagrass_Feb_2018 - Leschenault_Seagrass points where Year = '2018' Leschenault_Seagrass_Feb_2019 - Leschenault_Seagrass points where Year = '2019' Leschenault_Seagrass_Feb_2020 - Leschenault_Seagrass points where Year = '2020' Leschenault_Seagrass_Feb_2021 - Leschenault_Seagrass points where Year = '2021' Leschenault_Seagrass_Feb_2022 - Leschenault_Seagrass points where Year = '2022' Leschenault_Seagrass_Feb_2023 - Leschenault_Seagrass points where Year = '2023' Leschenault_Seagrass_Extent_Apr_2009 - Leschenault_Seagrass_Extent where Year = '2009' Leschenault_Seagrass_Extent_Feb_2015 - Leschenault_Seagrass_Extent where Year = '2015' Leschenault_Seagrass_Extent_Feb_2016 - Leschenault_Seagrass_Extent where Year = '2016' Leschenault_Seagrass_Extent_Feb_2017 - Leschenault_Seagrass_Extent where Year = '2017' Leschenault_Seagrass_Extent_Feb_2018 - Leschenault_Seagrass_Extent where Year = '2018' Leschenault_Seagrass_Extent_Feb_2019 - Leschenault_Seagrass_Extent where Year = '2019' Leschenault_Seagrass_Extent_Feb_2020 - Leschenault_Seagrass_Extent where Year = '2020' Leschenault_Seagrass_Extent_Feb_2021 - Leschenault_Seagrass_Extent where Year = '2021' Leschenault_Seagrass_Extent_Feb_2022 - Leschenault_Seagrass_Extent where Year = '2022' Leschenault_Seagrass_Extent_Feb_2023 - Leschenault_Seagrass_Extent where Year = '2023' Leschenault_Seagrass_Cover_Apr_2009 - Leschenault_Seagrass_Cover where Year = '2009' Leschenault_Seagrass_Cover_Feb_2015 - Leschenault_Seagrass_Cover where Year = '2015' Leschenault_Seagrass_Cover_Feb_2016 - Leschenault_Seagrass_Cover where Year = '2016' Leschenault_Seagrass_Cover_Feb_2017 - Leschenault_Seagrass_Cover where Year = '2017' Leschenault_Seagrass_Cover_Feb_2018 - Leschenault_Seagrass_Cover where Year = '2018' Leschenault_Seagrass_Cover_Feb_2019 - Leschenault_Seagrass_Cover where Year = '2019' Leschenault_Seagrass_Cover_Feb_2020 - Leschenault_Seagrass_Cover where Year = '2020' Leschenault_Seagrass_Cover_Feb_2020 - Leschenault_Seagrass_Cover where Year = '2021' Leschenault_Seagrass_Cover_Feb_2020 - Leschenault_Seagrass_Cover where Year = '2022' Leschenault_Seagrass_Cover_Feb_2020 - Leschenault_Seagrass_Cover where Year = '2023'

Princess Royal Harbour was surveyed in January and March 2021. Seagrass species distribution (Posidonia australis, Posidonia sinuousa, Posidonia coriacea, Halophila sp., Ruppia sp., and Amphibolis sp.) and cover (as percentage cover classes: 0, <15%, 15-45%, 45-75%, >75%) was recorded across 263 observations points across the estuary. The type of meadow (continuous or patchy), epiphytic cover on seagrass (as none, very low, low, medium, high or very high), and macroalgae cover (as percentage cover in categories: 0, <15%, 15-45%, 45-75%, >75%) were recorded at each site. At approximately a third of the sites, physical water profiles, secchi depth and photosynthetically active radiation (euphotic depth) were recorded. When observation locations were inaccessible by boat, sites were accessed from kayaks to make observations. The datasets making up the seagrass survey data are: PrincessRoyal_Seagrass - point dataset PrincessRoyal_Seagrass_Extent - polygon showing presence/absence PrincessRoyal_Seagrass_Cover - polygon showing % cover Layers: PrincessRoyal_Seagrass_Jan_2021 - PrincessRoyal_seagrass points where Year = '2021' PrincessRoyal_Seagrass_Extent_Jan_2021 - PrincessRoyal_seagrass_Extent where Year = '2021' PrincessRoyal_Seagrass_Cover_Jan_2021 - PrincessRoyal_seagrass_cover points where Year = '2021'