Horseshoe Crabs in Hong Kong: Current Population Status and Human Exploitation

  • Paul K.S. Shin
  • HiuYan Li
  • Siu Gin Cheung


An updated survey, using both random transect and walk-through search methods, at 17 shores in Hong Kong in summer and winter showed that juvenile horseshoe crabs (Tachypleus tridentatus and Carcinoscorpius rotundicauda) were significantly reduced by over 90% in density since 2002. Of the shores where juveniles were found, the highest density of T. tridenatus was 0.31 and lowest 0.08 ind 100 m–2. Juvenile C. rotundicauda was only found using the walk-through search method, with the highest record of 1.17 and lowest 0.17 ind hr–1 person–1. The mean prosomal width of juvenile T. tridentatus obtained from the walk-through survey varied from 2.6 to 5.5 cm, which corresponded to an age of 4–8 years old. A larger size range for C. rotundicauda was, however, noted, from 2.5 to 9.0 cm.

The degree of human exploitation of adult horseshoe crabs (T. tridentatus) in Hong Kong was estimated through interviewing 34 seafood restaurants, 150 fish sellers and fish handlers, and fishermen in two local fish wholesale markets over a 13-month study period. A total of 1,023 horseshoe crabs were caught in 2004–2005, with 72% from mainland Chinese waters. Apart from releasing back to sea, an average sale of 17 horseshoe crabs per month was estimated. While the sale of horseshoe crabs was low by comparison with other marine species of economic importance, human exploitation still contributes a potential threat and puts further pressure on the mature population of horseshoe crabs in Hong Kong due to their long maturity period and declining densities of the juveniles.


Tidal Level Horseshoe Crab Horizontal Transect Prosomal Width Horseshoe Crab Population 
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We would like to thank funding support from the Environment and Conservation Fund from the Hong Kong Special Administrative Region Government and Woo Wheelock Green Fund, Hong Kong. The presentation of this paper at the International Symposium on Science and Conservation of Horseshoe Crabs was supported by a travel grant from the Scientific Committee on Ocean Research, International Council of Science, USA.


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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Department of Biology and Chemistry, Centre for Coastal Pollution and ConservationCity University of Hong KongHong KongChina
  2. 2.Department of Biology and ChemistryCity University of Hong KongHong KongChina

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