In the past, research on horseshoe crabs has mainly focused on medical and ecological aspects. In the early years of horseshoe crab research, horseshoe crabs used for experiments or blood harvesting were mainly caught in the wild because horseshoe crabs are not easy to breed in captivity. More recently, as the number of horseshoe crabs has been greatly reduced, many scholars and conservationists have begun to discuss and study the economic value of horseshoe crabs. In the past, horseshoe crab conservation policy was mainly discussed from aspects such as public education, habitat maintenance, government policy, permit issuance, and ecological funds.
Regarding the “public education” aspect, previous scholars found that long-term and local public education is key to the conservation of horseshoe crabs, and public education programs were also used to attract local interest in horseshoe crabs (Chen, Yeh et al. 2004, Kwan, Cheung et al. 2017). Public education helps people know more about these animals, their importance and the necessity of their conservation. For example, Kwan, Cheung et al. (2017) discuss the horseshoe crab conservation program strategy in Hong Kong, where the aim is to enhance the community’s understanding of horseshoe crabs through the program and to promote public participation in activities with horseshoe crabs (Kwan, Cheung et al. 2017). According to Kwan, Cheung et al. (2017), the public education promotion of horseshoe crabs from 2009 to 2016 not only increased students’ and the public’s understanding of the ecology and conservation of horseshoe crabs but also promoted a positive attitude toward related conservation issues. Public education promotes students’ understanding of the ecology and conservation of horseshoe crabs, and it also promotes a positive attitude among members of the public and students toward related conservation issues. In addition to the above promotional activities, Chen, Hsieh et al. (2009) proposed that the concept of conservation could be strengthened through the establishment of a network of volunteers who are involved in the public education efforts. These active groups of individuals can contribute significantly to conservation by helping with promotional programs, education, training, etc., which are of considerable benefit to conservation.
Chen, Yeh et al. (2004) discussed the strategy and implementation plan for horseshoe crab conservation on the islands of Kinmen, Taiwan. Their plan mainly aimed to help residents understand basic information about horseshoe crabs, the importance of their ecology and the necessity of protecting them through the implementation of public education and participation programs, so that people will actively carry out horseshoe crab conservation. In addition, the study also found that the horseshoe crab conservation program has been integrated with the local ecotourism industry, which can be applied not only to the biotechnology industry but also to enhancing the economic value of the local tourism industry. Kwan, Cheung et al. (2017) conclude that long-term public education is helpful in protecting the horseshoe crab population because the animal is widely used in food and biomedicine in Asia, and they also state that the educational efforts improved the public’s awareness of the conservation of Asian horseshoe crabs. For example, the aforementioned case of conservation education efforts in Hong Kong from 2009 to 2016 showed that the cultivation of horseshoe crab knowledge in local middle schools not only increased students’ understanding of horseshoe crabs but also promoted student enthusiasm toward horseshoe crab conservation. In the past, a series of horseshoe crab conservation public education programs, such as seminars, publications and television programs, were carried out on the islands of Kinmen. The core educational efforts targeted primary school students and residents, as well as Kinmen National Park and local government employees. Some postgraduate students have designed special courses on horseshoe crabs for middle school students so that these students can understand horseshoe crabs and to increase their willingness to support conservation of horseshoe crabs (Chen, Yeh et al. 2004, Yang, Chen et al. 2007).
Regarding “habitat maintenance” attribute there is an interesting phenomenon that can be seen in some studies on animal habitats. For example, MacMillan and Leader-Williams (2008) discussed the economic perspective of conserving wild geese. It was found that if habitat management is changed to allow for some hunting of geese, the WTP was reduced by £0.74 for residents and by £6.74 for tourists. This is quite an interesting result, indicating that the conservation awareness among tourists and residents in the area is becoming stronger than expected. Horseshoe crabs are a suitable indicator for monitoring environmental changes in coastal areas because they are large, easy to observe, and highly dependent on their habitat over the course of their life cycle (Rudloe 1979, Jegla 1982, Cohen and Brockmann 1983, Penn and Brockmann 1994, Chen, Yeh et al. 2004). However, various anthropogenic activities have caused serious damage to the habitat of horseshoe crabs, which has also led to the loss of a suitable environment for egg laying and nesting, especially in Southeast Asia (John, Jalal et al. 2011, John, Kamaruzzaman et al. 2011, John, Sihin et al. 2012, Lee and Morton 2016, Nelson, Satyanarayana et al. 2016, John, Nelson et al. 2018). Therefore, habitat maintenance is an important aspect of wildlife conservation.
As for the “government policy” component, securing the conservation status of horseshoe crabs in Japan and Hong Kong has been challenging, and their conservation status in Taiwan is even more precarious. The coastal areas near the Taiwan Strait used to have quite rich populations of horseshoe crabs, but due to problems such as overfishing, land reclamation and water pollution, it has become difficult to find horseshoe crab larvae on the western coast of Taiwan and in swamps on the islands of Kinmen (Chen, Yeh et al. 2004). Because horseshoe crabs can be used for food and biomedical research, there are no strict regulations or good catch management policies for the conservation of horseshoe crabs in Asian countries. Take Japan as an example. Due to the lack of special conservation, the horseshoe crabs in the coastal areas of Japan have been pushed from endangered to critically endangered due to overfishing (John, Nelson et al. 2018). It can be seen that the intervention of government policy is a very important factor in wildlife conservation. For example, MacMillan and Leader-Williams (2008) studied the economic value of wild geese and found that based on the different considerations of species conservation, if protected species of geese are classified by policy as endangered species for conservation purposes, the WTP would increase by £12.26 for residents and by £16.50 for tourists. John, Nelson et al. (2018) concluded that limiting coastal development, prohibiting illegal export and strictly implementing the law in restricted regions are very important for the sustainable conservation of horseshoe crabs. As mentioned above, the public has a greater sense of urgency for endangered species, so this concept can be applied to the conservation of horseshoe crabs. If the laws include more regulations concerning the conservation of horseshoe crabs, the public may pay more attention to their conservation. Chen, Hsieh et al. (2009) argued that Taiwan should further designate T. tridentatus as an endangered species through legislation or should use the Wildlife Conservation Law to conserve horseshoe crabs in Taiwan. According to Hwey-Lian Hsieh, a researcher at the Biodiversity Research Center of Academia Sinica, “All of the west coast of Kinmen is suitable habitat for horseshoe crab growth and should be preserved.” Hwey-Lian Hsieh proposed that the “Hou Protection Zone (Jinning)” be established according to the Fisheries Law. However, since horseshoe crabs are not a protected species, they are not protected outside the protection zone. Therefore, Hwey-Lian Hsieh suggested that the west coast of Kinmen be designated as a protected area1.
When it comes to “licensing requirements,” the Delaware Bay along the United States Atlantic coast has been an example site for quite successful rebreeding of horseshoe crabs due to the requirement of permits to catch horseshoe crabs (Hata and Hallerman 2008, Michels, Smith et al. 2008, Kreamer and Michels 2009). Kreamer and Michels (2009) concluded that such a successful example comes from an appropriate management mode, which is governed by strict laws and regulations. The catching of horseshoe crabs is not allowed in any other regions except for in the Delaware Bay, and only with a permit. Therefore, based on the successful example of the Delaware Bay, Kreamer and Michels (2009) concluded that in Asia, in addition to strict legal restrictions, quotas for catching horseshoe crabs should be implemented and fishermen should be required to have licenses so that fishery development and conservation can coexist and so that economic and conservation development can achieve a balance.
Regarding the “horseshoe crab conservation fund,” Lee and Yoo (2009) stated that the trade-offs involved have become a topic of considerable interest and have been used as an example for evaluating the relationship between economic benefits and environmental costs in nonmarket goods. Juutinen, Mitani et al. (2011) also concluded that the trade-off relationship could be used to understand tourists’ preferences between economic and conservation concerns. Mulatu, van der Veen et al. (2014) argued that price information and MWTP (marginal willingness to pay) can be used to evaluate the calculation of the trade-off relationship. Since any change must be made through payment to ensure improvement in different components of conservation, user pay was one of the most important concepts. The concept of user-pay can be used to understand the trade-off relationship. Therefore, user pay is also a very important component to consider in the evaluation of nonmarket goods (Chaminuka, Groeneveld et al. 2012, Cerda, Ponce et al. 2013).