High mortality rate by "Beached" with using the data the GLORYS12v1 CMEMS

[Motaeng]

Dear Ichthyop community,

I am using 3D data from CMEMS GLORYS12v1 for the South Atlantic Ocean region, in the coast of Brazil. I am simulating the larval dispersal of a fish species where its spawning area is close to the coast. For this study I am using vertical migration and Coastline Behavior: “Bouncing”. After the first simulations, I performed a mortality assessment and obtained a high mortality rate by “Beached”.

I would like know if this cause of mortality is common for this GLORYS12v1 data or is it possible to make some adjustment in ichthyop to adapt this mortality aspect?

Thank you for any possible guidance.

Best regards,

[barriern]

Hi Moateng

I am surprised because the bouncing behavior should lead only to marginal beaching mortality, in the case when the bouncing algorithm fails to bounce the particle.

Could you please send me, via WeTransfer or anything alike:

• Your configuration files (.xml files for parameters and areas)
• Eventually a sample of your Ichthyop output files
• And the link to the Glorys Dataset that you used?

So that I can try to see if I find some clue

Thanks

Nicolas

[Motaeng]

Thank you for your feedback @barriern,

link to access the data you requested: https://we.tl/t-fqIfL8zl1V

Link the Glorys Dataset: https://data.marine.copernicus.eu/product/GLOBAL_MULTIYEAR_PHY_001_030/download?dataset=cmems_mod_glo_phy_my_0.083deg_P1D-m_202311

Please tell me if it was possible to access the data, ok?

Thanks

Lucas

[barriern]

Hi @Motaeng

Sorry for the little delay. Good news, I was able to reproduce your error. Better news, I think I solved it. Could you please try the following .jar file?

https://filesender.renater.fr/?s=download&token=65e5b5f3-660b-4d02-9e2e-137aff398cc5

To make long story short, I believe the issue with bouncing was due to the fact that it was first developed for 2D applications and used the land-sea mask at the surface. But in your run, the particles hit land at depths. I have corrected the bouncing algorithm to include 3D mask when needed. It now seems to run and I don't have any bouncing mortality. Here is a figure showing one of the particles. The background colors is the bathymetry.

Nicolas

[Motaeng]

Dear @barriern,

Thank you very much for your help!

I performed some simulations on the file you sent, I still find some mortalities due to "Beached", but with a percentage below 20 to 30%, which is extremely acceptable for me, previously this mortality was 80 to 90%.

Thaks

Lucas