The sharks and rays at Singapore’s fishery ports
Introduction
Globally, one-quarter of sharks, rays and chimaeras are threatened with extinction due to targeted and incidental overfishing (Dulvy et al., 2014). Many species have life histories that make them vulnerable to extinction, i.e, slow growth rates, late sexual maturity, small litters and long inter-birth interval (García et al., 2008). This has led some to contend that the catch, sale, trade and consumption of all sharks and their parts should be banned (Dent and Clark, 2015; Dulvy et al., 2017; National Geographic, 2019). Others suggest, however, that while such bans may control some mortality, they will not completely solve the issue as most sharks are not a target species but are incidental bycatch of fishing operations (Simpfendorfer and Dulvy, 2017). This is particularly the case in Southeast Asia, where many marine species, including sharks, are not always targeted by fisheries but are caught alongside commercially valuable species in non-selective fishing gear such as trawls and drift gill nets (Arai and Azri, 2019; Arunrugstichai et al., 2018; Ariadno, 2011; SEAFDEC, 2017a). Therefore, even if sharks cannot be sold or traded, many will still be caught. An analysis by Simfendorfer and Dulvy (2017) reveals that 9% of current global catch of sharks is biologically sustainable, out of which 4% is managed for sustainability, and efforts to increase this percentage would be a more feasible solution to protecting shark populations than blanket bans. Moreover, some species of shark with high fecundity may be resilient to fishing pressure (Dulvy et al., 2017; Pinhal et al., 2012; Arunrugstichai et al., 2018).
As Singapore has a small Exclusive Economic Zone (EEZ) of up to 19 nautical miles (Ministry of Foreign Affairs Singapore, 2008) and a small fishing fleet consisting of four off-shore and 35 in-shore vessels consisting of trawlers (Singapore Food Agency, 2019), it largely relies upon imports from the region to meet its seafood needs (USDA, 2017). The majority (about 95%) of Singapore’s seafood comes from neighbouring countries in Asia, with Indonesia and Malaysia dominating the supply of warm water fish and other types of seafood including large volumes of ray meat (USDA, 2017; Boon, 2017). An area described as the ‘Indo-Pacific Biodiversity Triangle’ which encompasses parts of Southeast Asia, has been highlighted as one of two main hotspots where shark and ray biodiversity is particularly threatened (Dulvy et al., 2014). Indonesia and Malaysia are also ranked number one and nine respectively in terms of global shark and ray production (Dent and Clark, 2015). However, with little available species-specific and biological data from the fisheries of these countries (Jaiteh et al., 2017; White, 2007) it is challenging to understand the impact fisheries are having on elasmobranch populations (Hoggarth, 2006). Data collected on imported sharks and rays from Southeast Asia to trade hubs such as Singapore can help to fill these data gaps.
Sharks have arguably received the most conservation attention within the elasmobranchs (IUCN, 2014). There is, however, growing recognition that the overshadowed rays (Superorder Batoidea: shovelnose rays, electric rays, skates and stingrays) are in peril (Dulvy et al., 2014). Rays are increasingly dominating the elasmobranch catches (Dulvy et al., 2014), while wedgefishes (Rhinidae) and giant guitarfishes (Glaucostegidae) are considered the most imperilled marine fish families globally (Kyne et al., 2020). Wedgefishes and giant guitarfishes were recently listed on CITES Appendix II (CITES, 2019), which will impact their supply into Singapore if international trade is monitored and CITES guidelines enforced.
This study aims to better understand regional and local elasmobranch fisheries by collecting data on Singapore’s imports and landings of fresh, whole sharks, rays, wedgefishes and giant guitarfishes specifically: 1) numbers of individuals; 2) species composition; 3) biological characteristics including length and sex and 4) information about the supply chain. We then interpret these data to identify possible conservation concerns relating to these fisheries and the regional trade of elasmobranchs.
Section snippets
Data collection
Surveys in Singapore were conducted at Senoko Fishery Port (SFP) in the north and Jurong Fishery Port (JFP) in the south from September 2017 to September 2018, and January 2019 to January 2020. Senoko Fishery Port has 25 licensed fish merchants and Jurong Fishery Port has 103 licensed fish merchants (Singapore Food Agency, 2019). These ports receive whole, fresh products and are separate from ports in Singapore that receive dried goods such as dried shark fin. Surveys were conducted twice per
Numbers of rays, sharks and wedgefishes (incl. giant guitarfishes)
From the 51 surveys at both JFP and SFP (102 surveys total), data were collected on 13,817 rays, 2,480 sharks, and 1,297 wedgefishes (incl. giant guitarfishes). There were more elasmobranchs at JFP compared to SFP consistent with it being the larger port (Fig. 1).
Country of origin
According to the Singapore fish merchants, the majority of elasmobranchs sampled (58.1% of rays, 67.1% of sharks, 69.8% of wedgefishes and giant guitarfishes) were imported from Indonesia (Fig. 2). Malaysia was the second most cited
Discussion
The 43 elasmobranch species identified at Singapore’s fishery ports are known to live in coastal waters throughout their life or during various life stages such as for breeding and as juveniles (Ebert et al., 2013; Duncan and Holland, 2006). Coastal waters throughout Southeast Asia are biologically diverse but experience high fishing pressure (Pomeroy, 2012), particularly in Indonesia which is the second highest producer of capture fisheries globally (FAO, 2020a). Within Indonesia and
Conclusion
Southeast Asia has been identified as one of the highest priority regions in the world for improved fisheries management and data reporting (Dulvy et al., 2017). While the impact of fisheries on elasmobranchs in the region are somewhat understood, impacts from other coastal threats including pollution (Todd et al., 2010), habitat conversion (Van Oudenhoven et al., 2015) and the expansion of coastal aquaculture (Akber et al., 2020), should be explored. Admittedly, it is challenging for some
Funding
This project was supported by Wildlife Reserves Singapore Conservation Fund (WRSCF) and the National Geographic Society Exploration Grant, both of which funded the entirety of the project from data collection to the stipend of the lead author and research assistants. Shannon Cosentino-Roush’s involvement was supported by the Shark Conservation Fund and Madhu Rao’s involvement was supported by a Shark Conservation Fund grant to the Wildlife Conservation Society (WCS).
Declaration of Competing Interest
The authors report no declarations of interest.
Acknowledgements
This project would not have been possible without the support of; the kind fish merchants at Singapore’s fishery ports who were welcoming of our presence and research; the Singapore Food Agency for allowing us to conduct research at the fishery ports and giving us important insights to the industry; Karenne Tunn of The National Parks Board (NParks) Singapore for supporting the establishment and continuation of the project; Jeffrey Low and Anna Wong of The National Parks Board (NParks) and Neil
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Cited by (5)
Unraveling the trade in wedgefishes and giant guitarfishes in Singapore
2022, Marine PolicyCitation Excerpt :Clark-Shen et al. (2021) reported that some fish merchants, economically dependent on the trade in wedgefishes, have continued to import them between November 2019 and January 2020 even after CITES listings had entered into force [28]. Engaging these stakeholders for CITES compliance and fostering greater stewardship towards the conservation of these species is central to achieving legal, sustainable, and traceable trade [28,61,62]. The CITES management authority in Singapore has issued advisories to merchants at the fishery ports and informed them of the penalties, but our study highlighted the need to address knowledge gaps related to legislation and policies concerning shark and ray conservation and CITES listings.
Status of Southeast Asia's marine sharks and rays
2023, Conservation BiologyUntangling the Indonesian tangle net fishery: Describing a data-poor fishery targeting large, threatened rays (Superorder Batoidea)
2022, Aquatic Conservation: Marine and Freshwater Ecosystems
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This project was made brighter thanks to our dedicated researcher, co-author and friend Raj, who worked tirelessly to make this world better for all creatures, but sadly passed away October 2020.