It does look like most studies suggested small or no effects after less than 10 meters away, but I wonder how much they focused on eggs, larvae and zooplankton, which are plausibly more sensitive. For example, from this study (discussion):
Experimental air gun signal exposure decreased zooplankton abundance when compared with controls, as measured by sonar (~3β4βdB drop within 15β30 min) and net tows (median 64% decrease within 1 h), and caused a two- to threefold increase in dead adult and larval zooplankton. Impacts were observed out to the maximum 1.2βkm range sampled, which was more than two orders of magnitude greater than the previously assumed impact range of 10βm. Although no adult krill were present, all larval krill were killed after air gun passage.
This might be an outlier study, though. I had Perplexity attempt a systematic review here.
It does look like most studies suggested small or no effects after less than 10 meters away, but I wonder how much they focused on eggs, larvae and zooplankton, which are plausibly more sensitive. For example, from this study (discussion):
This might be an outlier study, though. I had Perplexity attempt a systematic review here.