Analysis Of Ecosystem Structure And Function In The Yangtze Estuary Marine Ranch

The research was focused on Yangtze Estuary marine reach sea ecosystem as the research object.Taking the ecological system of the Yangtze River estuary in the north of the marine grazing area(hereinafter referred to as the contrast sea area)as the comparison object,based on the data of the biological resources of the two sea areas in March,August and November 2016,the Ecopath with Ecosim 6.5 software was used.The Ecopath model of the Yangtze Estuary Marine ranch demonstration area and the contrast sea area ecosystem was constructed.This study covers most of the energy flow in the two sea areas,studies the structure and function of the marine ecosystem of the Yangtze Estuary Marine ranch demonstration area and the contrast sea area,evaluates the Yangtze River estuary Marine ranch ecosystem,and proliferates the ocean pasture.And provide a theoretical basis for the direction of conservation.The main conclusions of the study were as follows:(1)The sea area of the Yangtze Estuary Marine ranch Demonstration Zone was divided into 14 functional groups according to the sampling organisms,and 15 functional groups were divided into the contrast sea creatures.The trophic level of the functional group of the Yangtze River estuary Marine ranching was 1—3.77,and the trophic level of the functional group of the contrast sea area was 1—3.80,among which the phytoplankton and the debris functional group had the lowest trophic level,and the middle and lower layer swims the biological feeding fish and the bottom swimming biological feeding fish.The highest level of nutrition.There were 6 functional groups with ecological nutrition efficiency greater than 0.9 in the two sea ecosystems.The ecological nutrition efficiency of the marine lands in the Yangtze River estuary was 0.97,and the ecological nutrition efficiency in the contrast sea area was 0.96.The energy efficiency of the ecosystem was not high.(2)The ecosystem trophic level in the sea area of the Yangtze Estuary Marine ranch demonstration area and the contrast sea area mainly existed in the first to fourth vegetative levels,in which the energy flow to the first vegetative level accounted for the largest proportion,and the flow to the fourth vegetative level accounted for the smallest proportion.The energy conversion efficiency of each trophic-grade primary producer and debris in the Yangtze Estuary Marine ranch demonstration area and the contrast sea area ecosystem was 7.505% and 6.06%.The energy conversion efficiencies of the two seas at the II and III trophic levels were at a lower level,but the energy conversion efficiency of the Yangtze estuary Marine ranch was higher than that of the contrast seas.(3)There were two main main energy flow pathways in the ecosystem: the food chain and the food chain of debris,and the proportion of the food chain was higher than that of the food chain.(4)By comparing the total consumption,total output,total respiration and total debris flow in the two sea areas,the marine ecosystem of the Yangtze Estuary Marine ranch demonstration area was small.The TRR/TR of the two sea areas was 1.244 and 1.886,both of which were greater than 1,and the ecosystems of both sea areas became immature.The joint index CI of the two sea areas was 0.55 and 0.52,and the omnivorous coefficient SOI of the two sea areas was 0.252 and 0.244,both of which were at a low level.By comparing the two sea areas TRR/TR,CI,SOI,the Yangtze Estuary Marine ranch ecosystem is more mature.(5)The pedigree index of the Ecopath model of both sea ecosystems is greater than 0.5,and the whole model had a certain degree of credibility,and the model quality is acceptable.Through the above analysis,it can be found that the construction of the Marine ranch in the Yangtze River estuary had a promoting effect on improving the ecosystem maturity of the sea area.The inter-biological connection was closer and the degree of connection was higher,but the ecosystem was not mature enough,the food network structure was simple,and energy utilization was utilized.The rate was low and the scale of reef construction is small.