I agree that it may not be necessary to get research experience specifically in Marine Biology. My son is currently a PhD student in Aerospace Engineering at Michigan. He did a summer research program in Germany after his junior year, which was more materials engineering oriented (carbon fiber aerospace applications).
Germany has a lot of affordable summer research opportunities. They do not require German language skills.
My son attended Aachen University’s ten-week summer UROP program. Tuition is free. It includes basic German-language instruction and travel allowances. Here’s the UCLA link to the program. https://germanic.ucla.edu/study-abroad/urop-rwth-aachen/ Here’s the UROP website: https://www.rwth-aachen.de/go/id/wmy/lidx/1