Bring karka eggs to Owain.
This is still a problem. It seems the area around Owain’s Refuge seems to be home to a special kind of Ninja Karka.
There are extremely frequent instant or near-instant respanwns of defeated Young Karka, quite often in the form of multi-spawns of two or more Karka at once. Sometimes these additional Karka vanish after a couple of seconds (possibly to a location that should not be accessible to them from where they were standing) if they are not aggroed, but if they are aggroed – for example by spawning at point blank distance to the player – the whole beach turns into a vile deathtrap.
The difference between a safe run to a resource node and certain death is simply unpredictable.