Much as I would love to know whether aviators jettisoning bombs after unsuccessful patrols ever conked a shark on the head...

My primary curiosity stems from how potentially disruptive events such as sinkings and the accompanying oil releases might have been, or perhaps the effects of battle. I don’t imagine there were many pressing concerns about wildlife at the time, and maybe the answer is simply “it’s too difficult to know.” So more broadly, what about the environmental toll the war took in other areas (climate change/CO2 aside)?