Centre for Fisheries Ecosystems Research, Fisheries and Marine Institute of Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
PLoS One. 2022 May 20;17(5):e0268440. doi: 10.1371/journal.pone.0268440. eCollection 2022.
Spatial heterogeneity in food web structure and interactions may reconcile spatial variation in population and community dynamics in large marine ecosystems. In order to assess food web contributions to the different community recovery dynamics along the Newfoundland and Labrador shelf ecosystem, we quantified species interactions using stable isotope mixing models and food web metrics within three sub-regions. Representative samples of each species caught in trawls and plankton tows were analyzed for stomach contents and stable isotope ratios (δ15N and δ13C) to parameterize isotope mixing models. Regional variation, highlighted by the diets of three economically important species, was observed such that the southern region demonstrated a variety of trophic pathways of nutrient flow into the higher food web while the diets of fish in the northern regions were typically dominated by one or two pathways via dominant prey species, specifically shrimp (Pandalus sp.) and hyperiids. Food web metrics indicated that the low-diversity northern regions had higher connectance and shorter food chain lengths. This observed regional variation contributes to our understanding of the role of specific forage species to the ecosystem which is an essential contribution towards ecosystem-based management decisions.
食物网结构和相互作用的空间异质性可能协调大海洋生态系统中种群和群落动态的空间变化。为了评估食物网对纽芬兰和拉布拉多大陆架生态系统不同群落恢复动态的贡献，我们在三个子区域内使用稳定同位素混合模型和食物网指标来量化物种相互作用。在拖网和浮游生物拖网中捕获的每个物种的代表性样本被分析胃内容物和稳定同位素比值（δ15N 和 δ13C），以参数化同位素混合模型。区域变化，由三种具有经济重要性的物种的饮食突出显示，观察到这样的情况，即南部区域表现出多种营养物质流入更高食物网的途径，而北部区域鱼类的饮食通常由一种或两种途径主导，通过主要的猎物物种，特别是虾（Pandalus sp.）和 hyperiids。食物网指标表明，低多样性的北部区域具有更高的连接度和更短的食物链长度。这种观察到的区域变化有助于我们理解特定饲料物种对生态系统的作用，这是基于生态系统的管理决策的重要贡献。
