Having just returned from a SCUBA diving trip to the Honduran Bay Island of Roatan I saw first hand what happens when we mess with natural systems. For those that don't know, the Lionfish, an Indo-Pacific native species, has somehow been introduced into the Caribbean, where as an invasive species with no natural predators, it is decimating fish populations and destroying reef ecosystems. The way this invasive species made it into the Caribbean are unknown although theories ranging from intentional personal aquarium releases to hurricanes destroying commercial aquariums and accidental releases abound.
Last year while diving in Bonair I also saw a lot of Lionfish and they have been found as far north as New England in the summer months. What I discovered this trip was what happens when we try to compensate for a problem and end up creating yet another problem. In Bonair the visiting SCUBA diver generally can not take Lionfish and only Divemasters take them. The result is that there are quite few Lionfish. In Roatan, any diver who takes a course and demonstrates a modicum of skill with a Lionfish spear is given a license. In our group of 27 dives a little over half took the course and got a license. For the remaining 5 days of diving we took 140 Lionfish. We had to travel significantly outside the normal diving sites to find that abundance of Lionfish as the most dived sites had few if any so an impact is clearly being made. The larger ones we kept for a party on Friday evening (and Lionfish are delicious) but the smaller ones were fed to the Moray eels and Groupers, just as the Divemasters in Bonair did/do in an effort to develop natural predators for the Lionfish.
What was interesting was that the Moray's, usually a very shy and reclusive fish, have now become very aggressive. When they see divers, instead of hiding as they naturally would do, they come along side and start looking for the free dinner. We never saw a Moray naturally attack a Lionfish, they only want the dead ones off the spear.
This leads me back into the the realm of process automation and control. When we as engineers develop a solution to a problem, we need to remember to think of the unintended consequences. In the "old days" when control loops were manually controlled with single loop controllers a human operator made a set point adjustment based on process performance trying to balance production volumes with product quality. As the process aged and equipment sufferred wear tha process became more difficult to control so the operator called in maintenance who made an adjustment or fixed a minor problem. WIth sophisticated computer control and measurement systems we can now run processes in a way that maintains production volumes and product quality as equipment wears to the point that when failures occur they no longer need just minor adjustment but we see catastrophic failure requiring massive replacement of equipment.
Likewise, in an effort to get ever more information from our processes automatically we have connected them to business systems introducing cyber security risks that never existed before. This is not to say we should not do these things but rather that as engineers we need to pay more attention to the unintended consequences any solution we propose may carry with it and try to minimize them.