Special Issue Survey of Cetaceans in Captive Care

334 Couquiaud• Partitions also can be made of concrete piles.Piles can be solid or hollow and filled with sand.This ensures a resistant and durable partitioning,but cannot be easily moved or modified.• Timber is frequently used as partitioning, fencing,walkways, and platforms in natural facilities. Avariety of wood types can be used for their durabilityand resistance to marine borers in marineenvironment such as teak, greenheart, and bakauwoods. Wood piles used in marine installations(e.g., wharves, jetties, breakwaters, etc.) usuallyreceive preservative and antifouling treatments toincrease their life span. Creosote oil is a mixtureobtained from the distillation of coal and tar andis a good preservative. CCA (Copper ChromeArsenate) is another widely used wood preservative.They both have excellent antifouling properties,but they are toxic. Creosote contains impuritiesthat are toxic, carcinogenic, and mutagenic.In some regions of Canada, its use is banned inprotected water supply areas or in swimmingareas whether protected or not (Anonymous,1995). Experiences have indicated that 3.5% ofarsenic from CCA is leached from the timberafter one month of exposure to running water,and arsenic contamination of potable water suppliesoccurred due to the leaking from a timbertreatment plant. The effect on marine mammalsis unknown; however, if toxins from these productsaffect humans, they potentially could affectcetaceans living permanently in their vicinity.Therefore, I recommend to look for alternativewood treatments, such as silicone and epoxy, oruse naturally resistant untreated woods. Woodshould always be carefully maintained to preventalgal and fungal growth. It also can become rapidlyslippery if not regularly scrubbed. I suggestthat the use of smooth-surfaced wood for walkingplatforms be avoided and that groove patterns beincorporated to increase foothold.• Nets (nylon fishing nets or rope nets, either looseor mounted on frames) should be banned for useas fences, partitions, or gates in dolphin enclosuresbecause they are extremely dangerous forthe animals. As reported by several facilities andby Myers & Overstrom (1978), they have beenused in the past, resulting in the death of animalsby suffocation because dolphins entangleda part of their body in the net and were unable towithdraw. They can only be used as a device torestrain an animal or push it toward a pool. Onlyin maternity pools can a special kind of net beused as a “baby cot” (see “Baby Cot” section).Artificial Environment• In pools, concrete walls are used to partitionspace between primary and secondary pools orthe medical pool. These do not allow physical,Figure 5.26. Net dangerously used as separator (Photographfrom Pr. Lam Khee Poh)acoustic, or visual communication between animals.Pools normally are connected by gates.If the water surface is level with the concreteplatforms, a concrete hump or a low stainlesssteel separator can be installed between pools toprevent dolphins from sliding over the partition.• Stainless steel bars and chain link fences alsocan be used as partitions, but pools should notbe subdivided if the original design did notinclude provisions of space for this purpose.Spacing between bars or meshes will either bewide enough or small enough according to thehoused species to prevent their rostrum fromgetting stuck between them.Pool and Enclosure Surroundings• Platforms and beaches used by dolphins toslide-out will be very smooth and nonabrasive,and edges will be rounded. Trainers shouldwear appropriate no-slip footwear.• Walkways around the pools are exposed towater and, therefore, will be made of or coveredwith no-slip and waterproof materials, and theyalso should be properly drained. Waterprooftreatedconcrete and concrete covered with noslipmaterials are recommended. Stone pavingis suitable for natural or semi-natural facilities.Sand and gravel are not recommended becausethey can easily be washed away and are too softand unstable for walking and pushing carts.Furthermore, according to several surveyedfacilities, they can be used by the public tothrow at the animals. Aggregated sand or gravelare preferred. Rubber and vinyls without nosliptreatment, metal, or wood are not recommended;they are slippery and difficult to maintain.Wood, with the exception of teak and a fewother types of wood that are resistant to marineenvironments, tends to rot quickly. Marinewoods are suitable for footpaths and fixed orfloating platforms, but should be kept clean and