Blame fishermen for the loss of fish?

Few seem to consider that there are at least 4 species that have been introduced since the 1950s, and are fierce competitors for space and food on Hawaii's reefs.

While tropical fish collectors go out for a few hours a few days a week, these voracious fish feed 24/7 and will hunt down anything that will fit into their mouths. Just so happens that aquarium fish are about that size. 

Let's look at some statistics for just one invasive species.

Roi consumes 99 tons annually per 3 square miles in Kona.
That's 33 tons of biomass per square mile.
West Hawaii Coastline: 147 miles. Reef might extend out 0.25 miles. That's 36.75 square miles. 
Roi therefore consumes about 1212.75 tons of fish per year, or 2.4 million pounds.

It's all right here.
http://data.nodc.noaa.gov/coris/library/NOAA/CRCP/other/grants/NA10NOS4100062/10_FISHTALK_Roi.pdf