In the complex and competitive world of oceans, different size of plants and animals exist. All of them compete for the limited resources; e.g., nutrients, sunlight, minerals etc. Size-specific and intraspecific predation is common among zooplankton. We design a model food chain and explore dynamics, and patterns of species abundance in ocean. The proposed mathematical model is based on a parameter; exponent of closure, $m$. A value of $m$ less than $1$ represents both size-specific and intraspecific predation among zooplankton. The mathematical model has been extended to include random movements of all the constituent populations by adding Fickian diffusion. Eigenvalues and amplitude equations are used to figure out relevant parameter spaces for numerical exploration. An analysis of the spatial system in the neighborhood of a critical parameter is performed using amplitude equation. Choosing appropriate control parameter from the Turing space, existence conditions for stable patterns are derived. Equal density contours were plotted for all the constituents of the model food chain. Epidemiological significance of these spatial patterns is provided.

在复杂而竞争激烈的海洋世界中，存在着各种大小的动植物。他们所有人都在争夺有限的资源；例如，养分，阳光，矿物质等。浮游动物中常见的有大小特异性捕食和种内捕食。我们设计了一个模型食物链，并探索了海洋中物种丰富度的动态和模式。所提出的数学模型是基于参数的。闭合指数，$米$。值$米$ 少于 $\mathrm{1个}$代表浮游动物之间特定大小的捕食和内部物种捕食。通过添加菲克扩散，该数学模型已扩展为包括所有组成种群的随机运动。特征值和振幅方程式被用来找出相关的参数空间，以进行数值探索。使用幅度方程对关键参数附近的空间系统进行分析。从图灵空间中选择适当的控制参数，得出稳定模式的存在条件。为模型食物链的所有组成部分绘制了等密度等高线。提供了这些空间格局的流行病学意义。