WHAT WILL YOU HEAR?
Some places are very quiet; some a sonically 'alive'. You will have to experiment to find the best places. While listening to whales and dolphins is lots fo fun, there are many other creatures which make sounds underwater. Remember also, that before Dolphin Phone came along, listening to underwater sounds was an expensive and time consuming proposition. You may discover underwater sounds that have never been heard! You may also find links between sounds and various habitats. For example, we wonder why 'snapping shrimp' seem to prefer boat marinas where pollution and toxic bottom paints abound, over cleaner waters just outside the entrance. If you want to explore our last earthly frontier, dolphin phone will open up a whole new dimension.
- Dolphins.Whales:
You will often hear dolphins when you cannot see them. They are easily identified by their high pitched squeeks. They also emit a 'clicking' sound used to locate fish. Sometimes they are very quiet and even though they are close to your boat you won't hear much. Other times, you can hear them through the boats' hull! Whales are generally identified by lower pitched grunts and moans.You will probably hear more than you will see with whales. Listen to whales as they dive and search for food. Different whale specied tend to emit different noises and scientists are trying to determine the exact meaning of the different sounds. This is an area where 'amateur scientists' using a Dolphin Phone can contribute greatly to the general knowledge about the meaning of these 'vocalizations'.
- Boat Sounds:
Listen for the crackling and popping of 'Snapping Shrimp'. They seem to thrive in most marinas and in many bays and anchorages. They create a snapping noise with their large claw. Scientists disagree as to the purpose of the snapping. Some say it's a warning to other shrimp nearby. Others say the shrimp shoot out a jet of water from their claw to stun prey. Whatever the reason the snapping goes on day and night. You will also hear a lot of boats. Listen for the different sounds made by sailboats, power boats, Jet Skis, and different outboard motors on dinghys. With practice you can pick out whether a boat uses a diesel or petrol power engine, hear pumps, and bubbles from outboard exhausts. Some boats are very quiet and you can only hear them at a range of 30-50 metres. Some are lounder and you can har them out to 1/2 kilometre or more. - SEALS and Dugongs (Manatees):
Both make underwater sounds but not much has been recorded or described in scientific literature. A Dugong nursing pups will call them over distances of a few hundred metres. There is much work to be done recording and cataloging these 'vocalizations'. - FISH SOUNDS:
Many fish can make sounds. There are 'Croaker Fish' which as the name implies make 'croaking' sounds. There are species of coral dwelling fish that make sounds by gnawing on coral - perhaps to scare preditors or attract mates. Large Groupers make 'grunts' to signal theiir displeasure at your presence. There may be many more if we start looking for them. Again, this is an excellent place for the amateur scientist to make meaningful contributions to marine science. - SHIPS:
Large ships generate very low frequency sounds and vibrations which can sometimes be picked up several miles away. Many factors are involved including speed and direction of the boat. If you are near a port, try listening to a ship as it maneuvers into its berth. Getting within 200 - 300 metres should allow you to have a good listen as tug boats grind their engines and the ship thrusts forward and backwards to position itself at the wharf.When you get out from the shore on a boat, many of the interfering sounds found close to shore disappear and you are able to hear sounds much further away.