Question: Can we use an arduino to run a photodiode and interference filter to detect bioluminescence?

This is a fun idea. l assume the bioluminescence will be detected only at night since it will be swamped by sunlight during the day. At night, bioluminescence will be the only source of light underwater assuming that the sensor is shielded from lights from ships, etc. So it is not necessary to use a filter that passes only the wavelengths emitted by marine organisms. There will not be any other wavelengths to filter out. If there are other light sources, the signal from bioluminescence will probably be contaminated whether or not a filter is used.

Any light sensor that can detect visible light can be used as long as it is extremely sensitive. Although bioluminescence can be spectacular at night, it might not be bright enough to register on most sensors. For example, most photographs of marine bioluminescence are taken with some combination of high ISO, wide aperture, and long exposure (multiple seconds).

The TSL2561 is a common light sensor used with Arduino. It uses a silicon photodiode and is therefore more sensitive to light than an LED used as light sensor. It can register a signal in as little as 0.2 lux which is about the brightness of a full moon on a clear night. This sounds promising, but in practice I have found that the sensor barely registers when it is in my house near a window in the middle of a cloudy day.

As proof of concept you could plug in a TSL2561 to a Nano Data Logger and see if it registers anything when dunked in glowing water (put the whole thing in a mason jar).

Chris

@mimiss has marked @amallozzi as a co-author.

I am curious about how this will help make shipping safer. I have extensive experience in ship traffic management and this project sounds interesting along the lines of safety. What are your thoughts on how detecting bioluminescence can help ships' pilots avoid accidents? My own thought is that if bioluminescence is stimulated by the passing of a ship (which I think may be true, based on very limited observations), then a bioluminescence detector placed at the edge of a shoal area (near a ship channel) might send a signal to a ship-board receiver to let the ship's pilot/captain know that the vessel is getting close to the shoal.