Human pressures on ecosystems from landscape transformation and harvesting can result in changes to body size and functional traits of affected species. However, these effects remain very poorly understood in many settings. Here we examine whether and how fishing and the attributes of coastal seascapes can operate in concert to change the body size and functional traits of the giant mud crab, Scylla serrata; a prized fisheries species. We captured 65 legal sized (> 15 cm carapace width) male giant mud crabs from 13 estuaries in southeast Queensland, Australia. These estuaries span a wide range of fishing and catchment landscape transformation intensity. We made a total of 9000 external morphometric measurements in the study. There was a distinct effect of estuarine landscape context on body size, with the largest individuals captured from systems with bigger inlets and lower extent of intertidal flats. Variation in functional traits was most often associated with variation in fishing pressure and human population size in the catchment. Crabs from areas with less commercial fishing pressure and lower human populations in the catchment had the largest chelipeds. We also found effects of urbanisation (negative correlations), intertidal flats (inconsistent effects) and mangrove extent (positive correlations) on the size of some functional traits. Our results show that human pressures can have sublethal effects on animals in estuaries that alter body size and functional traits. These phenotypic responses might have consequences for the fitness and ecological roles of targeted species, and the yields of fisheries catches.

景观转换和收获对人类生态系统造成的压力可能导致受影响物种的体型和功能特征发生变化。但是，在许多情况下，对这些影响的了解仍然很少。在这里，我们研究了捕鱼以及沿海海景的属性是否以及如何协同作用，以改变巨型泥蟹Scylla serrata的体型和功能特征; 珍贵的渔业物种。我们从澳大利亚昆士兰州东南部的13个河口捕获了65个合法尺寸（> 15厘米甲壳宽度）的雄性巨蟹。这些河口涵盖了广泛的捕鱼和流域景观转换强度。在这项研究中，我们总共进行了9000次外部形态测量。河口景观背景对人体大小有明显影响，最大的个体是从入口较大，潮间带程度较低的系统中捕获的。功能性状的变化通常与流域内捕鱼压力和人口规模的变化有关。来自商业捕鱼压力较小且流域人口较少的地区的螃蟹中螯虾的数量最多。我们还发现了城市化的影响（负相关），潮间带（不一致的影响）和红树林的程度（正相关）对某些功能性状的大小。我们的结果表明，人的压力可能会对河口的动物造成致命性影响，从而改变其体型和功能特征。这些表型反应可能会对目标物种的适应性和生态作用以及渔业产量产生影响。