河北唐山曹妃甸-乐亭海域自然牡蛎礁分布及生态意义

牡蛎礁是生态系统服务价值最高的海洋生境之一，目前我国自然牡蛎礁分布和生态现状的基础信息仍然较缺乏。于2019年3月对河北唐山曹妃甸-乐亭海域自然牡蛎礁的空间分布、生态环境、牡蛎生物学和礁体动物群落开展了调查，并评估了该牡蛎礁的生态系统服务价值。该海域自然牡蛎礁分布于溯河(SR)、溯河口海域(SRE)和捞鱼尖海域(LYJ),总面积约15 km~2,是目前我国面积最大的自然牡蛎礁。基于96个牡蛎样品的16S rDNA检测，共识别出92个长牡蛎Crassostrea gigas、3个侏儒牡蛎Nanostrea fluctigera和1个巨蛎属未知种Crassostrea sp.。自然牡蛎礁中牡蛎平均密度介于104—3912个/m~2之间，不同礁区间牡蛎平均密度的大小排序为：SRE>SR>LYJ (P<0.05),平均生物量的大小排序为：SR>SRE>LYJ (P<0.05),平均壳高的大小排序为：SR>SRE=LYJ (P<0.05)。在该牡蛎礁内记录到49种礁体动物，其中软体动物16种、节肢动物16种、环节动物8种、棘皮动物5种、腔肠动物2种...

Distribution and ecological status of natural oyster reefs on the coast of Caofeidian-Leting, Tangshan, Hebei Province

Oyster reef is an important marine habitat that provides a variety of ecosystem services, including water filtration, nitrogen removal, carbon sink, habitat provision and erosion control. In the past decades, most of natural oyster reefs in the Chinese coasts were lost due to overfishing, pollution, sedimentation and habitat destruction. To date, little information was available on spatial distribution and ecological status of natural oyster reefs in China. This study investigated the spatial distribution, ecological environment, oysters and reef-associated resident benthic macroinvertebrate communities at the natural oyster reefs on the coast of Caofeidian-Leting, Tangshan, Hebei Province, and furthermore assessed the ecosystem service values of the natural oyster reefs on the coast. The natural oyster reefs, including three major distribution zones, namely Shouhe River (SR), Shouhe River estuary (SRE) and Laoyujian (LYJ), occupied the total area of about 15 km². To our knowledge it was recognized as the largest natural live oyster reefs in China. Ninety-two of 96 oyster specimens collected from the natural reefs were identified as pacific oyster Crassostrea gigas, 3 specimens for Nanostrea fluctigera and 1 specimen for unknown Crassostrea sp based on 16S rDNA gene sequence analysis. The mean live oyster densities ranged from 104 to 3912 ind./m² at the natural oyster reefs. The mean oyster metrics were ranked as follows (P<0.05):SRE > SR > LYJ for oyster densities, SR > SRE > LYJ for oyster biomass and SR > SRE=LYJ for oyster size (shell height). A total of 49 resident benthic macroinvertebrate species, belonging to 16 mollusks, 16 arthoropoda, 8 annelids, 5 echinodermata, 2 coelenterata, 1 sipuncula and 1 chordata, were recorded at the natural oyster reefs. The mean total densities of resident benthic macroinvertebrate communities varied between 28 and 552 ind./m² at the natural oyster reefs, with ranking as follows:SRE > SR > LYJ (P<0.05). The total densities and biomass of resident macroinvertebrate communities had significantly positive correlations with the oyster densities at the natural oyster reefs. The economic value of the full suite of ecosystem services derived from the natural oyster reefs was recently estimated to be as high as RMB 6.90×10⁸RMB/a. The discovery of the natural live oyster reefs contributed significantly to valuable information on the spatial distribution and ecological status of temperate coastal habitats in China. It was suggested that a national marine ranching demonstration zone should be built on the coast through the conservation and restoration of oyster reefs and seagrass beds.