Species for Sale: Hippopotamus
by Thomas Gomersall
It’s no secret that Hong Kong is a major hub for the illegal wildlife trade, both as a destination and transit point for the smuggling of wildlife products. And over the years, much has been made of its ties to the trade in ivory, pangolin scales, rhino horns and shark fins, as well as its largely ineffectual wildlife crime laws.
But alongside elephants and pangolins, plenty of less well-known, sometimes even rarer species and their parts are also smuggled through the city. Without greater awareness of their plight, public pressure on the Hong Kong government to tackle the illicit trade (the type that helped to secure the 2018 ivory ban) will not be great enough to save these species.
“Species for Sale” is a new WWF-Hong Kong blog series that aims to shed some light on these forgotten victims of the wildlife trade, exploring why they are targeted, the ecological consequences of their decline, and what can and is being done about it. We begin the series by taking a look at the trade in hippopotamus parts.
Species
The hippopotamus (Hippopotamus amphibius) — hippo for short — is a large mammal found in freshwater lakes and rivers in sub-Saharan Africa. It only comes on to land at night to graze, spending the day largely in water where it sleeps, mates, gives birth and defecates. Although herbivorous, it possesses long, sharp ivory canine and incisor teeth, which are used solely for battles over mates and territory.
Item on Sale
Although harder to carve than elephant ivory, hippo teeth are nonetheless a popular alternative for ivory traders due to them being cheaper and easier to smuggle (Andersson, 2020). Hong Kong is the single-biggest buyer of hippo teeth, importing over 90 per cent of the 771,000 kg that have been traded internationally since records began in 1975, with over 75 per cent of those imports coming from Tanzania and Uganda (Andersson & Gibson, 2017).
Uganda is a particularly significant exporter of hippo teeth to Hong Kong, supplying over 65 per cent of post-2001 imports. A cull of hippos there in the 1950s and ongoing hunting since have created a considerable stockpile of teeth, which has proven hard for a country struggling with poverty and civil instability to resist selling. Furthermore, while neighbouring countries like Rwanda were placed under review for hippo trade by the Convention on International Trade in Endangered Species (CITES) in 2007, Uganda was not, allowing for hunting to go unrestricted until 2014, when the country officially banned its hippo teeth trade. Despite this however, illegal killing has continued to increase (Andersson, 2020; Anderson & Gibson, 2017).
Price
Combined with the climate crisis and disease outbreaks, hunting has driven an estimated seven to 20 per cent decline in the global hippo population over the last decade, with a further 30 per cent decline predicted over the next three. At this rate, hippos could be extinct within 100 years (The University of Hong Kong, 2017).
Hong Kong’s hippo teeth trade in particular could be having even more devastating effects than once thought, as a 2017 study found that the declared volume of teeth imported since 1975 was higher than that exported from Tanzania and Uganda. The volume of teeth unaccounted for within this timeframe indicates that an estimated 2,700 more hippos — two per cent of the global population — were killed to supply the demand in Hong Kong than official trade records suggest. There are also concerns that the recent wave of elephant ivory bans could lead to a spike in hippo teeth trading, as was the case in the aftermath of the 1989 ivory moratorium (Andersson & Gibson, 2017).
The loss of hippos could potentially have disastrous consequences for African freshwater ecosystems. Because they graze on land but defecate in water, hippos play a key role in transporting nutrients between the two habitats, which directly affects the diversity and productivity of phytoplankton that form the basis of aquatic food chains (Schoelynck et al, 2019). Some fish even feed directly on hippo dung or on algae that grows on their skin (Oneyeanusi, 1999). Moreover, their wallowing creates new pools and channels that provide habitat for smaller species and tramples vegetation that would otherwise become overgrown and restrict other animals’ access to water (Olson, 2020).
How can Hong Kong help?
Despite Hong Kong’s disproportionately large role in the hippo teeth trade, it has, to date, made no moves to combat it. However, the passage of the 2018 ivory ban does create a legislative precedent for the government to take such action. Currently the ban only applies to elephant ivory, but it could be amended to include hippo teeth too, as the UK has recently done with its own ivory ban (Andersson, 2020; Horton, 2019).
“We have a really important and unique opportunity here to have a huge impact on hippo conservation,” says Astrid Andersson, a PhD student at the University of Hong Kong and co-author of the 2017 hippo teeth study. “If you’ve taken the first step of tackling the biggest of the ivory trades […], then why not, by the same token, include other species that are threatened by the exact same ornamental trade?”
Hong Kong could also potentially take things even further at the next CITES conference of parties, where signatory countries meet to decide on upgrading protections for certain species. Currently, hippos are listed under Appendix 2 of CITES, meaning that the trade of their parts is technically legal. But should a country that falls within their range propose upgrading protections, all the other members would then vote on that. And as the biggest international buyer of hippo teeth, Hong Kong’s vote would be more influential than most (Andersson, 2020).
“The CITES convention needs to re-assess the impact of the trade on hippo populations” says Dr David Olson, Conservation Director for WWF-Hong Kong. “It’s time to take stock and to afford more protection to this species.”
In the meantime, consumers must continue to avoid buying ivory and support efforts to pressure the government to protect hippos.
References
· Andersson, A., interviewed by Thomas Gomersall, 2020, The University of Hong Kong.
· Andersson, A. and L. Gibson. 2017. ‘Missing teeth: Discordances in the trade of hippo ivory between Africa and Hong Kong’. African Journal of Ecology, vol. 00: pp. 1–9.
· Horton, H. ‘Hippo ivory to be banned as Government set to close ‘loophole’ in poaching laws’. The Telegraph, 12 October 2019. https://www.telegraph.co.uk/news/2019/10/12/hippo-ivory-banned-government-set-close-loophole-poaching-laws/ (Accessed: 16 January 2020).
· Olson, D. (PhD), interviewed by Thomas Gomersall, 2020, The University of Hong Kong.
· Onyeanusi, A.E. ‘Some ecological roles of Hippopotamus (Hippopotamus amphibious Linn. 1758) in fish production: possibilities for integrated fish-cum Agric production system’. 13th Annual Conference of the Fisheries Society of Nigeria (FISON), New Bussa, Nigeria, 1999, pp. 282–285.
· Schoelynck, J., Subalusky, A.L., Struyf, E., Dutton, C.L., Unzué-Belmonte, D., Van de Vijver, B., Post, D.M., Rosi, E.J., Meire, P., Frings, P. 2019. ‘Hippos (Hippopotamus amphibius): The animal silicon pump’. Science Advances, vol. 5: eaav0395.
· The University of Hong Kong, Hong Kong’s rampant consumption of hippo teeth combined with incomplete trade records imperil threatened hippo populations in Africa, [website], 2017, https://hku.hk/press/news_detail_16672.html (Accessed: 17 January 2020).
