I have multiple polygons that have zero to 4 points (sampling sites with a list of species) in them. I need all the information from these sampling sites ONCE per catchment. So instead of up to 4 times the same species I need ONE list of species per polygon. My only idea is to aggregate or merge the points per polygon (no idea how, the points dont have a common field I could use), then export it to Access, erase repetitive species and then import it back to GIS. Maybe there is an easier way.
I am using ArcGIS 10.4.
EDIT: With spatial join, I added a column to my points shape with the ID of the polygon. That means if 2 sampling sites (points) are in one polygon, they now have the same polygon-ID. In one column I have the species names, with one line per species. That means that for each polygon there are multiple lines (as many as different species) but for the ones where more than 1 sampling site are located, some species are double or three of four times in this list. That I have to change.