High density and secondary production but variable recruitment of a sea urchin in subtidal barren areas of Hong Kong

Autor: Juan Diego Urriago Suarez, Jian-Wen Qiu, Jane C. Y. Wong, Clement P. Dumont
Rok vydání: 2021
Předmět:
Zdroj: Regional Studies in Marine Science. 48:102027
ISSN: 2352-4855
Popis: Sea urchins can cause a state shift from algal beds to barrens through grazing, but little is known how management measures may affect their population dynamics. We compared four populations of Heliocidaris crassispina inhabiting the subtropical shores of Hong Kong with different levels of protection: a no-take reserve, a marine park, and two sites with no restriction to fishing. Bi-monthly surveys revealed 1% to 36% juveniles ( − 1 in the second year. These values are high when compared with available sea urchin production data in the literature (0.001–8.44 g AFDW m−2 year −1). The no-take reserve population had the highest sea urchin density and biomass, but its production was not the highest in the second year of study due to low recruitment. The results were discussed with respect to the dilemma of spillover effects of marine protected areas and losing macroalgae to urchin grazing.
Databáze: OpenAIRE