The assessment of carrying capacity of marine biology resources based on primary productivity method——A case study of coastal waters of Rizhao

Abstract

The technical bottlenecks of threshold determination and key parameter calibration in carrying capacity of resources and environment urgently need to be broken through, and then establish a standardized quantitative evaluation method. In the present study, several key parameters such as primary productivity, phytoplankton organic carbon content and trophic level were obtained through investigation and experimental analysis. The nutrition dynamic model and the Tait coastal energy flow model were used to estimate the total quantities of marine biological resources. Then, the threshold of carrying capacity of marine biological resources was calculated based on the “resource-consumption” model. For example, according to the survey results in 2016, the annual average primary productivity of sea area under Rizhao jurisdiction was 428.22 mg/(m2·d) and the annual production of phytoplankton was 9.19×106 t. Meanwhile, the average trophic levels of fishes, shrimps and crabs, and cephalopods were 3.85, 3.92 and 3.90, respectively. The annual production of fishery resources (fish, shrimp and crab, and cephalopod) in the sea area was 38.9 thousand tons calculated by the “nutritional dynamic model”. In addition, the shellfish resources in shallow sea within 10 m depth contour was 55 thousand tons calculated by the Tait coastal energy flow model. Thus, according to the annual per capita intake of aquatic products of 21 kg, the total carrying capacity of marine biological resources in Rizhao coastal waters was 1.928 6×106 people. Meanwhile, according to the annual per capita protein intake of 30 kg, the total carrying capacity of marine biological resources in Rizhao area was calculated to be 1.687×105 people. Taken together, this paper describes a quantitative assessment technique with wide applicability for carrying capacity of marine biological resources. This will contribute to substantial utilization of the marine biological resources and establishment of the monitoring and early warning of resources and environment carrying capacity in a way of overall planning of land and sea.