SEAWORLD FACT CHECK:

SeaWorld claims its animals “do not appear to carry toxic burdens” as wild whales do. However, the fish SeaWorld whales eat are the same – as SeaWorld itself insists – as the fish humans (or wild whales) eat. Wild whales build up their contaminant loads through the food they eat, the most obvious route of uptake for mammals, in a process called bioaccumulation1. Even restaurant-quality fish carries the risk of exposing people to toxins such as mercury and persistent organic pollutants, which is why food safety agencies recommend limiting or regulating the consumption of oceanic fish, especially those known to carry high levels of contaminants such as mercury2 and especially during pregnancy. It is therefore highly likely that SeaWorld’s whales carry some measurable toxic burden (since they eat a solid diet of fish sourced from the ocean), although it may be lower than in some “urban” marine environments.

The industry has claimed that the calves of first-time mothers frequently die in the wild and therefore it shouldn’t be surprising when this same pattern occurs in captivity3. SeaWorld often points to patterns in the wild as justification for these patterns occurring in captivity (see, e.g., entry under TEETH). However, the reason first-time cetacean mothers in the wild frequently lose their calves is because they offload their toxic burdens (accumulated throughout their lives to that point) onto this calf through lactation. Many contaminants in cetacean habitat are “lipophilic” – they bond to fat, of which cetaceans have a great deal as blubber – and when females mobilize this fat to make milk, the toxins come with it, effectively poisoning their first calf with a lifetime’s load (Schwacke et al. 2002). Subsequent calves get a smaller dose (accumulated only since the previous birth) and survive it.

So SeaWorld argues on the one hand that its whales are kept safe from pollution hazards by carefully maintaining tank hygiene and careful food sourcing and handling, yet then suggests a pattern caused by pollution in the wild is to be expected in those same tanks.

In fact, it is likely that the high mortality of first-born calves in captivity is a result both of contaminant offload (however low toxic burdens may be in captivity, a first-time mother’s toxins would still challenge a newborn calf’s constitution) and poor motherhood skills in captive-raised females, who are not socialized by an experienced group of older female companions as in the wild.

Finally, while SeaWorld is generally correct about the risk contaminants pose to apex predators such as orcas, it refers to this risk as if it were uniform throughout the oceans. However, only some populations of orcas are threatened by pollution to the degree implied by SeaWorld’s response. In fact, many orca populations, particularly those in the southern hemisphere, are living in relatively healthy waters and carry toxic burdens that are relatively low (see, for example, Aguilar et al. 2002).

Finally, while research on captive orcas regarding contaminant transfer may contribute to conservation of free-ranging orcas, this research could have (and should have) been initiated (and much of it already published) years ago, as pollution has for decades been a recognized threat to free-ranging orca populations, including the endangered southern resident population (which was listed in 2005 under the Endangered Species Act). Yet no such research was conducted using SeaWorld’s captive orcas to help build impact models until now, coincident with SeaWorld’s recent public relations campaign post-“Blackfish.”

Aguilar, A., Borrell, A., and Reijnders, P.J.H. 2002. Geographical and temporal variation in levels of organochlorine contaminants in marine mammals. Marine Environmental Research 53: 425-452.

Schwacke, L.H., Voit, E.O., Hansen, L.J., Wells, R.S., Mitchum, G.B., Hohn, A.A. and Fair, P.A. 2002. Probabilistic risk assessment of reproductive effects of polychlorinated biphenyls on bottlenose dolphins (Tursiops truncatus) from the Southeast United States coast. Environmental Toxicology and Chemistry 21: 2752–2764.

1 Bioaccumulation is the process of an animal accumulating contaminants through ingesting food or directly from the water – see USGS' definition. SeaWorld’s definition – the “focusing of chemical pollutants as they are passed further up the food chain” – actually describes a different phenomenon, known as “biomagnification.”

2 See, for example, EPA fish advisories.

3 See, for example, Daytona Beach news on Marineland calf death.

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