Native Oyster - Unsuitable habitat (Depth)

A raster file of the extent of areas in the National study region that are predicted to have an unsuitable environment for native oyster restoration based on refined thresholds.

There are six bands:
1. depth
2. upperTemp
3. spawning15
4. spawning13
5. speed
6. mud

These are binary layers with 0 representing areas that are potentially suitable based on the refined threshold value for that variable, and 1 representing areas that are unsuitable. Cells with a value of NA were not in the extent of the study area or were beyond the extent of the source data. 

The binary layers were created by applying a threshold to the original environmental layers which were resampled to a 1 km resolution with EPSG 3035.
Sources for the depth layer were bathymetry layers of lowest astronomical tide in metres.
Attribution: EMODnet Bathymetry Consortium (2020).EMODnet Digital Bathymetry (DTM 2020).EMODnet Bathymetry Consortium 
https://doi.org/10.12770/bb6a87dd-e579-4036-abe1-e649cea9881a 
Accessed March 2023.
The data are available under Creative Commons Attribution 4.0 International
Original resolution is approximately 0.001 degrees. 
The relevant tiles were merged. The raster was then re-projected onto a raster with the same extent as the study area with 1 km resolution and coordinate reference EPSG:3035.

Sources for the current speed, temperature and salinity data is the Scottish Shelf Re-analysis 3.01. 
The Scottish Shelf Re-analysis Model is available under Open Government Licence for public sector information https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.
Attribution: Barton, B., De Dominicis, M., O'Hara Murray, R., Campbell, L. 2022. Scottish Shelf Model 3.02 - 27 Year Reanalysis. doi: https://doi.org/10.7489/12423-1
The model is run on an irregular triangluar grid. Daily average salinity values (practical salinity units PSU) and temperature are available every day from 1993 to 2019 on the nodes of the grid. Daily average velocities in the u and v (m/s) direction are available every day from 1993 to 2019 at the centre of the triangular grid cells. 
There are 20 depth layers in the model, the values at the deepest layer were extracted.
The daily average speed was calculated as the magnitude of the two velocities.
Minimum and maximum daily value, and mean and variance were calculated for each quarter.
For each variable the data were converted to a raster with the same extent as the study area with 1 km resolution and coordinate reference EPSG:3035. For any raster cell that contained at least one node/centre, the mean of the points were assigned to that cell. For raster cells that did not contain a node/centre, the cell value was calculated using inverse distance weighting of the four nearest points with an inverse power weighting of 2 using the "gstat" package.
The raster was clipped to the inshore boundary of the Scottish Shelf Model extent which was determined using a concave hull around the nodes with a ratio of 0.003.

Source data for the salinity layer are point locations of Particle Size Analysis (PSA) results from
1. British Geological Survey (BGS) Geoindex Offshore: Seabed Sediment Data, Sediment folk classification. http://mapapps2.bgs.ac.uk/geoindex_offshore/home.html
Available under Open government Licence. Contains British Geological Survey materials (c) NERC [2023]; Contains Department of Energy and climate change data (c) DECC; contains Joint Nature Conservation Committee materials (c) JNCC [2023]; contains Department of Environment, Food and rRural Affairs material (c) Defra [2023]
Accessed: September 2023
2. JNCC Marine Recorder Public UK snapshot - v20220124 https://hub.jncc.gov.uk/assets/b9934e31-39b6-41f9-9364-d1e93db68307
Available under Open government Licence. Contains material from: Centre for Environmental Data and Recording (CEDaR, Northern Ireland); Data Archive for Seabed Species and Habitats (DASSH); Joint Nature Conservation Committee; Natural England; Natural Resources Wales (formerly Countryside Council for Wales and referred to as such or CCW in this version); Porcupine Marine Natural History Society; Scottish Natural Heritage; Seasearch (Marine Conservation Society); Shoresearch Kent Wildlife Trust; The Wildlife Trusts
Accessed: June 2023
3. INFOMAR. Geological Survey Ireland. INFOMAR Seabed Sediment Samples
Available under Creative Commons. CC BY 4.0 the following is granted: Rights Share — copy and redistribute the material in any medium or format; Adapt — remix, transform, and build upon the material for any purpose, even commercially. The licensor cannot revoke these freedoms as long as you follow the license terms. Requirements Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
Accessed: August 2023

Any points on land and any points that had a percentage mud, sand and gravel totalling >101% were removed.
Inverse distance weighting was conducted on each sediment fraction to create three rasters at 1 km resolution and ESPG: 3035.
The outer boundary of the final extent was the outer limits of the PSA records based on a concalve hull with a ratio of 0.1. The coastal extent was 500 m inland or within 1 km of a PSA record on land.