you said you are an undergrad. have you taken ecology yet? not trying to be rude just asking.

you are missing a huge ecology problem with you example. if the bass truely are eating the goby (non-native) then the native speice that they normally eat has a reduction in predator pressure. this is going to casue an increas in this animal. this increase in this animal will, in turn, decrease the number of prey. and if the native fish and the non-native goby share the same prey item, this reduce the prey's numbers even faster, eventually colasping that part of the ecosystem. now they may start eating something else or they may die out which would then casue the bass to either search for a new prey item or die out. if a new or another prey item is selected, then the new prey items number will decrease rapidly due to the loss of the two other prey items. eventually, this ecosystem will crash especially if it is closed or partly closed.

this goby example shows that a top-down ecosystem and quickly turn to a bottom-up and crash. it may not happen today, towmorrow, or 5 years from now, but it can happen and will likely happen if nothing is done. i know you feel strong about his subject but there are many more things going on in an ecosystem other than just 2 or 3 fish. they are all connected and if the balance is shifed, bad things can happen. there is no such thing as a perfect world and no such thing as an ecosystem with only a 2 step chain. you have much, much to learn.