Temporal and spatial comparison of food web structure in marine pastures in the Pearl River Estuary: Implications for sustainable fisheries management

Peng Xu; Weiguo Zhou; Mujiao Xie; Dewen Ding; Anning Suo

doi:10.1002/ece3.8903

Temporal and spatial comparison of food web structure in marine pastures in the Pearl River Estuary: Implications for sustainable fisheries management

Ecol Evol. 2022 May 13;12(5):e8903. doi: 10.1002/ece3.8903. eCollection 2022 May.

Authors

Peng Xu^{1

2}, Weiguo Zhou^{1

3}, Mujiao Xie^{1

2}, Dewen Ding^{1

3}, Anning Suo^{1

3}

Affiliations

¹ CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou China.
² University of Chinese Academy of Sciences Beijing China.
³ Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) Guangzhou China.

Abstract

The biological and ecological integrity of marine ecosystems in the Pearl River Estuary (PRE) has been compromised due to overfishing and water pollution. Fishing moratorium and artificial reef construction have been implemented in Wanshan and Miaowan for resource protection and restoration. Therefore, food web structure and trophic pathways of Wanshan, Miaowan, and Wailingding in different temporal and spatial situation will be determined using the Ecopath model, as well as the keystone species affecting these ecosystems, which can provide a basis for fishery management. The results showed that the energy transfer efficiency of IV and V trophic levels (TL) was higher than that of II and III-TL before and after fishing moratorium, and the energy transfer efficiency of artificial reefs II and III-TL was only slightly higher than that of nonartificial reefs in Wanshan. In addition, the mean values of ecosystem property indicators (consumption, respiration flow, total system throughput, and total biomass) after the fishing moratorium were significantly higher than those before the fishing moratorium. The average value of the ecosystem attribute indicators (consumption, respiration flow, total system throughput, and total biomass) of artificial reefs is lower than those of nonartificial reef areas, which may be related to the differences in community composition between artificial reefs and non-artificial reefs. Finally, Nemipterus japonicus and Gastrophysus spadiceus are keystone species that distinguish the Wanshan and Miaowan artificial reefs from other areas. Overall, the fishing moratorium has a positive effect on the short-term restoration of fishery resources, mainly restoring short-life cycle organisms. However, the construction of artificial reefs will be more conducive to the persistence of ecosystem restoration. In addition, reasonable proliferation, release and fishing of N. japonicus and G. spadiceus will be beneficial to the sustainable utilization of fishery resources.

Keywords: artificial reefs; ecosystems; fishing moratorium; food webs; keystone groups.