"Numa" the first purposed acquired captive killer whale being moved in the sea-pen in 1966.
Perhaps one of the most irksome comments that come from the animal-rights community and self-styled marine mammals expert is that of the use of sea pens.
This has again been muted with the fanciful idea that 'Lolita' - the killer whale at Miami's Seaquarium - will be given over to animal-rights activists to be moved to a proposed but yet unbuilt sea pen in Washington State - due to her possible listing as an 'endangered' species.
Of course, it is not the case that marine mammals have not been successfully house in sea pens, as many facilities of this nature exist worldwide. Nevertheless, the misguided view that these facilities are promoted as the panacea to alleged welfare problems in facilities with closed life-support systems (LSS) is erroneous. In addition, and as is so often the case in these matters, this subject is more complicated than it appears.
Some years ago in 1988, the UK Government published an independent scientific report they commissioned into the welfare of cetaceans by Dr Margaret Klinowska assisted by Dr Susanne Brown. This report: A Review of Dolphinaria, still remains one of the most comprehensive research documents published and it led to the codification of new standards in cetacean care in the UK. Moreover, despite some reports, the review and subsequent Steering Committee Report did not recommend a ban on cetacean keeping in the UK.
In the report, Klinowska addressed the issue of sea pens and highlighted some of the problems with this system of accommodation.
"...Some groups and individuals believe that cetaceans should only be kept in open sea pens, with water changed by tidal flow. There are practical problems with sea pens, relating to ensuring the provision of good quality water at all times, to the prevention of the build-up of pathogens and parasites and to the safety of animals in extreme weather conditions. These can only be solved by having provision for water treatment if necessary, by constructing pens so that they can be easily cleaned and by having alternative accommodation available to which animals can be moved, when required. It therefore appears that all the facilities of a conventional establishment would be required to provide the back-up necessary to ensure the welfare of animals at all times, making the use of sea pens a very expensive option..."In the United States, their Animal Welfare Act (Subpart E—Specifications for the Humane Handling, Care, Treatment, and Transportation of Marine Mammals) makes clear statements as regards sea pens and water quality for marine mammals:
"...Ws (27) Any plans to keep cetaceans in sea pens need to include provisions to ensure the health and safety of the animals at all times.
(b) Water and power supply. Reliable and adequate sources of water and electric power must be provided by the facility housing marine mammals. Written contingency plans must be submitted to and approved by the Deputy Administrator regarding emergency sources of water and electric power in the event of failure of the primary sources, when such failure could reasonably be expected to be detrimental to the good health and well-being of the marine mammals housed in the facility. Contingency plans must include, but not be limited to, specific animal evacuation plans in the event of a disaster and should describe back-up systems and/or arrangements for relocating marine mammals requiring artificially cooled or heated water. If the emergency contingency plan includes release of marine mammals, the plan must include provision for recall training and retrieval of such animals..."The UK regulations for zoo and aquariums is also very clear that facilities must be able to control standards in aquatic exhibits so as not to work to the detriment of the animals.
This is a major issue for sea pens, if there is a serious environmental problem such as a pollution incident, there is little that can be done to intervene to addressing problem other than sealing the environment and supplement water treatment and flow by artificial means, e.g., a water treatment systems. Or removing the animals from the facility; which in many cases may be impossible. Unlike a closed systems used by zoos like SeaWorld's which has a module pool design which can allow isolation of pool units and water treatment systems that can be precisely adjusted and controlled.
Another pressing issue would be how would animals be rescued and removed from such environments. In the case of small cetaceans like bottlenose dolphins, this may not be a major problem but with large mammals such as killer whales, this certainly would be problematic without adequate holding areas and heavy-duty mechanical lifting equipment with access to safe alternate facilities.
Therefore, it can be seen that once again those protesting against the care of marine mammals in human care and demanding their release to coastal sea-pens are at least misguided and they have not fully considered the animal welfare implications of such schemes.
Blackfish: Please Release Me Let Me Go
Principles Of Water Treatment In Aquatic Mammal Pools