Localized beliefs, such as those described above by Anderson, can result in neighbors having profoundly different culinary cultures. These traditional preferences may, however, change over time as either environmental or social drivers change. For example, food item availability can alter, as can demand from a growing population and, likewise, trends in popular food culture. During the twentieth century, the hunting and harvesting of the oceans' animals increased dramatically with widespread and often indiscriminate industrial fishing practices being increasingly used. In addition, as human populations migrated to coastal areas, this also increased the need for aquatic resources (Jackson et al., 2001; O'Connor et al., 2011).

The increased hunting of terrestrial wildlife for food and other uses is of global concern and many studies have been conducted on the extent of consumption (e.g., Fa et al., 2002; Bowen-Jones et al., 2003; Lee et al., 2014) and the driving forces behind trade (e.g., Bowen-Jones and Pendry, 1999; Brashares et al., 2004; Rowcliffe et al., 2005; Lindsey et al., 2013). Similar concerns have emerged for the utilization of marine mammals, and other aquatic species, for consumption, bait, and traditional use (Alfaro-Shigueto and Van Waerebeek, 2001; Clapham and Van Waerebeek, 2007; Costello and Baker, 2011). In 2011, a thorough review of existing literature, media reports, and local knowledge documented the global extent of marine mammal consumption (Robards and Reeves, 2011) and compared this information with earlier datasets (i.e., Mitchell, 1975a,b; Brownell et al., 1978). This review highlighted several key points:

That marine mammals caught unintentionally in fishing gear had been increasingly utilized for consumption;

This paper builds on the excellent work of Robards and Reeves (2011) using published information and other information gleaned since 2010 and aims to evaluate what is known of all marine mammal consumption for food and other uses in Asia. We also consider the factors that motivate this consumption.

There is a long written and spoken history in Asian societies about marine mammals. The Chinese character for “whale” was first printed as early as 179 BC (Le Blanc, 1985) and there are myriad myths throughout Asia that are based on the belief that most marine mammals bring good fortune and that harming them can bring bad luck (Perrin et al., 1996). However, not all cetacean species elicit the same good will. For example, according to Chinese mythology, the Baiji (Lipotes vexillifer), which is now extinct, is the reincarnation of a young maiden who had been forced to leap into the Yangtze River to escape her evil stepfather. The stepfather is subsequently turned into a finless porpoise (Neophocaena phocaenoides). It is claimed that reverence for the Baiji stemmed from this legendary act of courage. The species was not eaten and only parts from stranded or by-caught individuals were used in Traditional Chinese Medicine (TCM). By contrast, the dislike of the stepfather is manifested in disregard for the finless porpoise, which, is both historically and currently hunted and consumed (Wang, 1965; Zhou, 1991). In southern China, marine mammal bones can sometimes be found in the temples dedicated to Tin Hau or Mā Zǔ (媽祖), the favored goddess of the fishermen (Andersen, 2009). In particular, some fishermen consider the “Chinese white dolphin” (Sousa chinensis) divine as this species is often perceived as “paying homage” to the goddess as groups of dolphins often occur near the shores upon which her temples are built (Andersen, 1971). Festivals in honor of Mā Zǔ in Fujian Province traditionally culminated with the consumption of dolphin meat, although this practice is now prohibited (Huang et al., 1997). In Vietnam, whale temples occur along the entire coastline and the religion that stems from the worship of whales is still very much practiced (Lantz, 2009). Vietnamese people mourn the death of marine mammals and bury those found floating or stranded. After some years, the bones are exhumed and then placed in dedicated temples (Nguyen and Ruddle, 2010). In India, fishermen also revere marine mammals and believe that the presence of dolphins enhances fishing catches (D'Lima et al., 2014) and that some dolphins even chase fish into fishermen's nets (Bijukumar and Smrithy, 2012).

There is anecdotal information about the use of marine mammal parts in traditional medicines and tinctures. For example, in both Cambodia and Malaysia, dugong (Dugong dugon) tears are used in love potions (Perrin et al., 1996) but only in TCM pharmacopeia is there a comprehensive list of the use made of specific marine mammal parts. TCM originated over 5,000 years ago (Xie and Huang, 1984) and modern pharmacopeia include over 11,500 ingredients originating from animals, plants, and minerals (Chen, 2011; Alves et al., 2013). Several studies have investigated the active components of TCM and some (non-marine mammal) ingredients are now regularly incorporated into both western and veterinary medicine (Nadkarni, 1976; Jiang et al., 1979; Hagey et al., 1993; Normile, 2003). Derivatives from at least 20 marine mammal species are detailed in Chinese pharmacopeia and are recommended for a variety of maladies (Read, 1982; Zhai, 1989; Zhao, 1990; Han, 1992; Li and Lin, 1992; Bensky and Gamble, 1993). The most commonly listed ingredients derived from cetaceans are oil, pancreas, and liver. These are prescribed for intestinal disorders, inflammation, and a variety of skin conditions. Dugong oil and ground bone are believed to have haemostatic properties. Pinnipeds and mustilids are generally used as either an enhancer or suppressor of various human appetites. There is little information on how prevalent the current use of marine mammal parts are in TCM but an agreement between Canada and China in 2011¹, allowing the import of Canadian seal parts to China, plus a proposal to increase trade in 2015², indicates that a market certainly exists.

Over 60% of the world's population live in Asia³ and, by its sheer mass and needs, the Asian population has a profound impact on global protein resources (Curran et al., 2002). The food needs of Asia puts extreme pressure on both agriculture and fisheries, exacerbated by the coastal location of most of Asia's mega cities (Hinrichsen, 1999; Tibbetts, 2002). Indeed, Asia's fishing fleet accounts for the majority of global fish landings (Watson and Pauly, 2013). Small-scale fishing in Asia is less well documented but certainly outweighs industrial fisheries (Kittinger, 2013). Global fish stocks are in rapid decline (Pauly et al., 2005; Pauly and Zeller, 2016) and studies outside Asia indicate that as fisheries resources become reduced, efforts can shift to other protein sources, including terrestrial bushmeat (Brashares et al., 2004; Rowcliffe et al., 2005). Marine mammal consumption has already featured in most Asian cultures, with 24 Asian countries having a history of consuming marine mammals (e.g., Prematunga et al., 1985; Leatherwood and Reeves, 1989; Andersen and Kinze, 1995; Perrin et al., 1996, 2005; Mills et al., 1997; Rudolph et al., 1997; Baker et al., 2010; Acebes, 2014). Robards and Reeves' (2011) review revealed several new trends in the consumption of marine mammals in Asia and they concluded that the pressure to feed human populations where hunger and poverty prevail, is increasing both the deliberate and opportunistic utilization of marine mammals as food.

Emerging studies indicate that some forests in Asia, unlike in Africa, are becoming devoid of wildlife as a consequence of over-hunting rather than deforestation (Harrison et al., 2016). In a region where the bulk of the human population occupies coastal areas and relies heavily on aquatic resources, it can be assumed that this loss is likely being mirrored in the marine environment. Terrestrial studies that have focused on understanding wildlife use provide useful tools and techniques that may well increase our understanding of this issue in the aquatic realm.

Terrestrial bushmeat studies generally rely upon a multi-disciplinary, socio-economic approach that can either collect novel data or use existing socio-demographic information to understand what drives use (Bowen-Jones and Pendry, 1999; Wilkie et al., 2005). Spatial models and the novel application of production/commodity analyses have successfully identified key areas of concern and likely consumers (Bowen-Jones et al., 2003; Schlesinger et al., 2015). Economic sustainability models have also been utilized to target potential markets (Fa et al., 2002). The illicit nature of illegal wildlife use has led to the successful adaptation of rapid assessment techniques that maintain the participant's confidentiality while still capturing key information (Conteh et al., 2015). Focused ethnological studies appear useful in both understanding the drivers of wildlife use and also in providing a foundation for future conservation and education activities that aim to establish sustainable use through changes in human practices (Nekaris et al., 2010; Scheffers et al., 2012).

Gavin et al. (2010) provide a comprehensive review of socio-economic methodology based on 100 studies. This provides useful guidelines for the improvement of study accuracy and may help to address the lack of data common to illegal wildlife trade and use activities (Gavin et al., 2010). In general, these modeling tools do not rely on quantitative data and may be applied without the need to collect primary data from market surveys and community interviews. Modeling and mapping exercises may, therefore, be most useful in discerning potential locations of concern for marine mammal species where future, focused studies may be directed.

There are also a wide variety of forensic tools available that allow better identification and analyses of wildlife parts (e.g., Ogden et al., 2009; Alacs et al., 2010; Linacre and Tobe, 2011). Some of these have already been utilized to reveal discrepancies in reported marine mammal bycatch, to determine the magnitude of trade and to develop kits that rapidly identify marine mammal species in situ in Asian markets (Baker et al., 2006, 2007; Lukoschek et al., 2009; Lo et al., 2013). These tools, designed specifically for non-specialists, will allow quantitative data collection both on type and volume of marine mammal parts in Asian markets. Such information will reveal the extent of marine mammal trade in key markets and, thus, allow identification of populations that may be unsustainably impacted. The use of social and online media has also been remarkably successful as a tool in identifying and, by working with law enforcement agencies, obstructing illegal trade (Krishnasamy and Stoner, 2016). In addition, short online searches conducted for this mini-review resulted in new information on marine mammals for sale in markets. Comprehensive searches may reveal which markets or locations persistently trade marine mammal parts and help to focus on site studies.

In many countries, the use of marine mammals for any purpose is illegal but legislation appears inconsistent and a lack of public awareness of the relevant laws has likely contributed to the continued illegal use of some aquatic species. A clearer integration of old and new laws has been shown to reduce marine megafauna use (Humber et al., 2015). In the many developing countries of Asia, limited government resources are often focused on laws that relate more directly to humans than to wildlife. In some countries, however, and Malaysia in particular, wildlife task forces have been established that investigate wildlife trade chains and have already reduced the level of open trading, as well as making progress in uncovering illegal trade routes⁵. Empowerment of management authorities and clear guidance and education on wildlife law may also assist in the reduction of marine mammal trade and use.

Investigative tools and methods, ranging from on-site market testing to online data mining, will be useful in discerning the scope of marine mammal use and trade and the factors that drive it. What will be more challenging for the marine realm is establishing a better understanding of trade or exchange of marine mammals at sea rather than through centralized markets, which is thought to be a common practice in some areas.

Finally, and in conclusion, the available information indicates that social, economic, cultural, and ecological aspects of marine mammal use are intimately linked and should be considered together if a pathway is to be mapped toward sustainability in Asia. Lessons and tools developed for terrestrial bushmeat studies will assist in making progress in investigating marine mammal use for consumption, bait and other purposes and can help to direct studies and activities to areas where impact is likely to be unsustainable.

LP reviewed and summarized all reference material and wrote the manuscript. HL conducted the literature search and the Chinese language online media review.

LP and HL are supported by the University of St. Andrews via the university's office in Hong Kong SAR.