|Scientific Name:||Phyllospadix japonicus|
|Red List Category & Criteria:||Endangered B2ab(i,ii,iii) ver 3.1|
|Assessor(s):||Short, F.T. & Waycott, M.|
|Reviewer(s):||Livingstone, S., Harwell, H. & Carpenter, K.E.|
Phyllospadix japonicus has a small distribution in Korea and a very limited range in Japan. There have been declines recorded in Korea. Major threats to this species are localized coastal development and shoreline hardening. In northern China this species was previously widespread over vast rocky shallow subtidal areas, but since the establishment of extensive kelp (algal) aquaculture nearly all the P. japonicus has been eliminated. The recruitment rate of this species is low as it inhabits a high energy environment, where conditions need to be right for seeds to be successful. The population of P. japonicus is naturally fragmented due to a lack of suitable substrate. Overall declines are estimated to be in the region of between 30 and 50 % over the three generation lengths (18 years) which meets the threshold for Vulnerable under criterion A. However, given the shallow depth range and patchy occurrence, the current area of occupancy of this species is estimated to be less than 500 km² and therefore this species also meets the threshold for Endangered under criterion B2, with a continuing decline in area and a fragmented population.
|Range Description:||Phyllospadix japonicus occurs in the northwestern Pacific from the northeast coast of China to South Korea and northwestern Honshu, Japan. Its distribution is very limited. However, in northern China this species has been eliminated from the region due to the establishment of extensive kelp (algal) aquaculture. Given its shallow depth range, patchy occurrence, and current distribution, this species has an area of occupancy estimated to be less than 500 km2.|
Native:China; Japan; Korea, Democratic People's Republic of; Korea, Republic of
|FAO Marine Fishing Areas:||
Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The range size of Phyllospandix japonicus is declining in Korea (K.S. Lee pers. comm. 2008). In northern China this species was previously widespread over vast rocky shallow subtidal areas, but since the establishment of extensive kelp algal aquaculture virtually all the P. japonicus has been eliminated (approximately 90% decline) (F.T. Short pers. comm. 2008). The distribution in Japan is very limited. This species is naturally fragmented due to a lack of suitable substrate. Overall declines are estimated to be in the region of between 30 and 50 % over the three generation lengths (18 years).|
|Habitat and Ecology:||Phyllospadix japonicus inhabits the intertidal and subtidal rocky bottoms of temperate regions of Japan and China. In South Korea, it occurs mainly on rocky substrata along the east coast. This species has been observed in both sheltered and open shores, but usually grows in high-energy environments. This species lives at depths from 0-8 m.|
|Use and Trade:||This species is used as roofing for fishers' houses in North China (F.T. Short pers. comm. 2008)|
Major threats to P. japonicus include coastal development, shoreline hardening and kelp aquaculture.
The recruitment rate of this species is low as it inhabits a high energy environment, where conditions need to be right for seeds to be successful.
|Conservation Actions:||The distribution of Phyllospadix japonicus falls into protected areas in South Korea (Environmental Conservation Areas or Special Coastal Management Areas) and is protected by 'The Marine Ecosystem Conservation and Management Act' in Korea.|
Green, E.P. and Short, F.T. 2003. World Atlas of Seagrasses. University of California Press, Berkeley.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.3). Available at: http://www.iucnredlist.org. (Accessed: 2 September 2010).
Kuo, J., Aioi, K. and IilzumiI, H. 1988. Comparative leaf structure and its functional significance in Phyllospadix iwatensis Makino and Phyllospadix japonicus Makino (Zosteraceae). Aquatic Botany 30(3): 169-187.
|Citation:||Short, F.T. & Waycott, M. 2010. Phyllospadix japonicus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 18 April 2015.|
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