Special Issue Survey of Cetaceans in Captive Care

344 Couquiaudlevel changes need to be as gentle as possible.Ramps of proper dimensions, made of no-slipmaterials, will provide access for wheelchairs,carts, and trolleys carrying fish or equipment.Every part of the enclosure should be easilyaccessible to the staff at all times. Avoid havingtrap doors, ladders, and catwalks as the access thefiltration plant room, power switchboards, andfood storage.The food preparation and storage rooms preferablywill be at the same level as the pool. Roadaccess to the main freezer allows unloading offrozen fish directly from the truck.All areas accessible to visitors should complywith regulations for the disabled.Figure 5.51. Acrylic tunnelFigure 5.52. Hemispherical acrylic windowleakage. The surface exposed to seawater will haveto be cleaned frequently to remove algae. It can becleaned by divers or a mechanical cleaning device.If a portion of the window is above water level,traces of salt can be removed regularly with softbrushes or sponges.A large majority of facilities have expressedthe wish to have an observation chamberwith viewing windows, off-limits to thepublic, which allows 24-h observations ofthe animals. This room can be equipped withhydrophones and an audio-video recording system.It is especially useful for monitoring pregnant andparturient females, and newborn calves.Levels and AccessTo achieve easy and efficient circulation aroundthe pools and enclosures for trainers and guests,LightingUnderwater and aerial lighting will be designedto prevent the exposure of animals to excessiveor insufficient illumination, which could disturbtheir behaviour and physiology.Underwater lighting in pools is optional, butit can be useful for training and observation, inemergency situations, and especially in facilitieslocated in high latitudes during the winter’searly nightfall. It can be installed on dimmers toprogressively reduce the light intensity. It will beused only occasionally and will be switched offearly in the evening. In no case should it be left onall night as it might disturb the animals’ diel cycle.The survey recommended that banquets and socialevents requiring bright illumination and generatingloud noise be avoided near the pools becausethey may disturb and stress the animals. At notime should the lighting be such that it causes theanimals discomfort or trauma (Anonymous, 1979-1984, 1995).In both natural and artificial facilities, aeriallighting is important to ensure the safety of trainersand keepers at nighttime around the pools. Polelights, bollards, or spotlights will provide uniformand minimal lighting. Mercury vapours and metalhalide lamps provide cold spectrum light; sodiumor incandescent lamps provide warm colour light.Lights should not be located directly over thepools because they are difficult to access and canshatter in the water.AcousticsDolphins and whales in the wild live in a fairly noisyenvironment. Creatures like snapping shrimps producea broadband background noise, and mysticetewhales can produce low-frequency sounds as loudas 195 dB (dB re 1µPa at 1 m) under water. In addition,the sounds of crashing waves, precipitation,and seismic rumblings also produce loud, low-frequency,background noise. The auditory system ofcetaceans is adapted to these natural sounds. Even