The Philippines is the center of marine biodiversity, and a lot of foreigners have flocked to our country because of that fact. In the past years, this recreational activity which was largely a tourist activity is being embraced by more and more Filipinos as well.
Sad truth of the matter though is that while this has helped bring in income to locals living around dive spots and helped make more individuals appreciate and protect our seas, a lot of divers remain unaware to the long term damage they cause in their relatively brief dives. Many times we worry about our own safety in open water, when in fact, we can sometimes be the most dangerous creature out there.
In my short albeit no less life-changing experience with diving thus far, I’ve picked up a few things here and there that I think every diver should know.
1) Check your sunscreen
Researchers estimate that some 4,000 to 6,000 metric tons of sunscreen wash off swimmers annually in oceans worldwide, and that up to 10% of coral reefs are threatened by sunscreen-induced bleaching. Look out for these:
- Paraben, cinnamate, benzophenone, and a camphor derivative, can trigger a viral epidemic that affects the zooxanthellae inside reef-building coral species. Without zooxanthellae, corals “bleach” and die. 
- Zinc oxide and titanium dioxide are ingredients that aren’t biodegradable and pose harm corals and sea life. Some also contain mineral oil (petroleum), which has a low solubility rate in water. 
And it doesn’t matter how little or how much of these types of sunscreen you use because coral’s exposure to a very small dose of sunscreen is enough to trigger the virus that causes coral bleaching. Choose to buy sunscreen made with natural or eco-friendly ingredients instead.
2) Master your buoyancy
By mastering your buoyancy, you get to conserve your air and minimize your impact on coral reefs. Studies show that areas frequented by divers have more damage to their coral reefs than non-dived areas close by due to divers touching, kicking or even sitting on the reef. 
A good practice therefore is to stay a meter away from corals to avoid hitting them, especially so if you still have to work on your buoyancy.
3) Mind your finning
Gary Cases of Divelink Cebu shared with me how irresponsible finning can affect corals. And it’s not just about your fins hitting corals either; it’s about the sediment you cause to stir. As little as 2mm of sediment build up on corals is enough for the algae to stop photosynthesis as sunlight is blocked.
Best practices would then be to minimize finning and to practice frog kicks vs. flutter kicks as this lessens disturbance on corals and sandy substrate.
4) Be a good house guest
Remember that you’re a visitor and that you’ve got to respect the hosts and their habitat. Avoid chasing marine species such as dolphins, whale sharks, and turtles as this can cause a great deal of stress and lead to transmission of diseases or death. Avoid feeding the fish as this interrupts their natural nutrient balance, which then disrupts healthy marine habitats. 
And remember the scene from Finding Nemo where he gets traumatized by divers taking one blinding, ear-piercing, dizzying photo after another just inches away? That’s a case where the “take nothing but photos” rule still doesn’t quite work out for the fish. So take it easy in shooting and using your flash.
5) Have a responsible diver’s mindset (even on land)
It is important for us to raise awareness and action to change how diving is done. And yet what may cause the greatest harm to underwater life are the things we do on land. What we do on land, in our everyday lives can have a bigger impact than diving.
So it’s best to think of eco-friendly habits, as the water temperature is changing due to greenhouse gas emissions and the sea is usually where most of world’s waste ends up.
What other things do you think divers should practice?
(All photos c/o Bo Mancao of Divelocal.net)