Analysis of environmental variables and fouling organisms on an experimental artificial reef area of Daya Bay Chen haigang South China Sea Fisheries Institute, CAFS Guangzhou, China

Goals of the artificial reefs project? From a human standpoint, artificial reefs bring together two odd bedfellows. Environmentalists creating habitat to help save our oceans and capitalists putting $131 into the local economy for every $1 spent on artificial reefs 02/13/03 STATUS REPORT FWC DIVISION OF MARINE FISHERIES NORTHWEST FLORIDA ARTIFICIAL REEF UNPUBLISHED REEF PROJECT

How to affect habitat environment? Firm, stable substrate for attachment Currents can result in the concentration of nutrient and plankton, and additional food source is provided Increasing biomass for food chain

Case:Yangkeikeng in Daya Bay Artificial reefs deployment site in Yangmeikeng Control area ： 1 、 4 、 5 、 6 、 11 、 12 Reef area: 10 Experimental area:2 、 3 、 7 、 8 、 9 Three deployment types of artificial reefs

Changes of environmental factors From Apr-2007 to Nov-2008, the result of linear fitting showed the increasing tendency of water temperature was RA(0.502) ＞ EA(0.371) ＞ CA(0.294) 。 From Apr-2007 to Nov-2008, the result of linear fitting showed the decreasing tendency of water salinity was CA(-0.336) ＞ RA(-0.237) ＞ EA(-0.228) 。

From Apr-2007 to Nov-2008, the result of linear fitting showed the decreasing tendency of water pH value was similar( ) 。 From Apr-2007 to Nov-2008, the result of linear fitting showed the decreasing tendency of dissolved oxygen was CA( ) ＞ EA(-0.084) ＞ RA(-0.082) 。

From Apr-2007 to Nov-2008, the result of linear fitting showed the increasing tendency of ammonical nitrogen concentration was CA(6.092) ＞ EA(3.938) ＞ RA(2.048) 。 From Apr-2007 to Nov-2008, the result of linear fitting showed the increasing tendency of nitrate nitrogen concentration was CA(27.696) ＞ EA(21.851) ＞ RA(11.605) 。

From Apr-2007 to Nov-2008, the result of linear fitting showed the decreasing tendency of phosphate concentration was CA(-5.308) ＞ EA(-4.232) ＞ RA(-2.444) 。 From Apr-2007 to Nov-2008, the result of linear fitting showed the increasing tendency of chlorophyll a concentration was EA(0.156) ＞ CA(0.040) ＞ RA(0.014) 。

Scores of the first two principal components (PC1 and PC2), PC1 and PC2 explained 66.99% of the total variance. Sampling sites are classified in three different groups, zone 1 mainly comprised from sampling sites of EA and CA, the sampling stations included in zone 2 are from RA, and zone 3 included RA and EA. There is a relationship among Dissolved oxygen, Salinity and Chl-a for PC1 that is associated with upwelling.

Changes of fouling organisms Before deployment of reef After deployment of reef

Seasonal changes of fouling organisms species A total of 116 species were collected and identified during four seansonal investigation. Among them, the species of fouling organisms on steel reef biofouled more quickly than those on concrete reef. species of fouling organisms Spring Summer Autumn Winter Concrete reef Steel reef

Seasonal changes of fouling biomass During four seasonal investigation, the biomass of the communities on concrete reef were winter ﹥ autumn ﹥ spring ﹥ summer. Among them, Balanus trigonus, O. plicatula and Pema viridis were the absolute advantage species, the tendency of which varied as the following:

Seasonal changes of fouling biomass During four seasonal investigation, the biomass of the communities on steel were winter ﹥ spring ﹥ autumn ﹥ summer. Among them, Balanus trigonus, O. plicatula and Pema viridis were also the absolute advantage species as on concrete reef, the tendency of which varied as the following:

Seasonal changes of community diversity Diversity index Evenness value Abundance

Biomass of different reef materials Among of different reef materials, the average biomass of fouling organisms on wood reef reached kg/m2. By comparison of 6 reef materials, effect of biofouling was followed by wood, plastic, aluminum, steel, tyre and concrete.

Factors affecting the fouling organism The results of DCA indicated that each attaching organism had its own distribution region. The results of CCA indicated that temperature and salinity, depth, transparence and dissolved oxygen were the dominate factors in the distribution of attaching organisms, and CCA taxis fairly reflected the correlation between the distribution of attaching organisms and environmental factors. 附着生物 DCA 种类排序 CCA 分析结果用双序图