This is only anecdotal, but some long time divers I've spoken with say that the amount of sea and coral life they used to see has greatly diminished over the past decades. I'm sure that there are any number of reasons for this, but I also think it is safe to assume that the huge increase in diving and divers has contributed to this reduction. To the extent that is true, we are stressing the environment when we dive. If we want to respect and hopefully be able to pass it on to future generations, it just seems basic common sense to do all we can to minimize the stress.
Yes I am part of the problem, that does not undermine my point.
No ... there has been no huge increase in diving and divers for quite some time ... and the amount of area that divers affect is miniscule in relation to the damage that has been done to our oceans. The culprits are many ... we can start with stormwater runoff, which has affected coastal areas immensely. Every time we pave over another street or parking lot we remove some of nature's filters ... allowing more and more untreated water to drain into our waterways. And as Gil in "Finding Nemo" so astutely put it ... all drains lead to the ocean. For coastal areas, stormwater runoff from development is one of the most significant factors leading to polluted waterways. Add to that untreated wastewater ... which in many parts of the world is the only kind of wastewater there is. Even some significant cities in the world still just dump their untreated wastewater a mile or two offshore and take the attitude "the solution to pollution is dilution" ... that's been a mantra used around the world for way too many years, and the cumulative effects have been catastrophic. But wastewater treatment plants are expensive, and without the money and will, that problem will get worse. Head off to some of the undeveloped parts of the world and you'll find that, culturally, people just dump their trash in the water. Check out beaches in popular diving areas like Bunaken and Raja Ampat and it's enough to make you weep. Too many people worry about damaging marine life by touching it without giving a thought to the damage that comes from them eating plastics, or getting entangled in ghost nets ... or the ever-popular practice of "dynamite fishing".
And let's not forget what the demand for tuna, shark-fin soup, and other markets around the world do when they remove the top predators from the food chain ... or the catastrophic effects of invasive species like the Caribbean lionfish, which were the result of careless human interaction that had nothing at all to do with scuba diving.
Add to that water pollution, acidification, changing weather patterns and other cumulative human effects that change the water conditions these creatures are used to living in, and you get things like the massive sea star die-off that's affecting the whole west coast of North America right now ... whole species dying off and we don't even know why, or whether or not there's anything we can do to change it. What we do know is that in just a couple short years the whole life cycle has changed, and species that once were kept in check through predation are now becoming dominant ... to the detriment of many other species.
The effects of scuba diving interaction is nothing ... not even in the noise level ... compared to the effects that massive development and population have had on our oceans over the past 50 years. But as long as there's money to be made by destroying our oceans and wiping out entire species within it, there will be plenty of people who will rationalize why it's OK. And there will be far too little effort put into doing something about it ... particularly finding solutions that are easily within our grasp, but because they would cost money and increase taxes, won't be utilized. Far easier to focus on the little things that don't make a damn bit of difference, but give people a sense that they're actually doing something to address the problem ...
... Bob (Grateful Diver)