The invasive kelp Undaria pinnatifida: a prominent Asian food source spreading in European waters

裙带菜（Undaria pinnatifida）是一种海带，在中国沿海水域被广泛种植作为食物来源，在中国和日本的人类营养中起着重要作用（日本称为裙带菜，中文称为“群菜”）。褐藻通常在海水养殖设施中养殖，那里的环境扰动和潜在的过度放养可能会降低年产量。与此同时，在其本土分布范围之外，裙带菜是一种迅速蔓延的入侵物种，具有超越各自本土海洋植物群的潜力。目前，它在欧洲水域的北部分布极限是荷兰海岸线，预计很快就会进一步扩散到德国海湾。中国和德国的研究团队在海藻生物学领域都享有盛名，通过合作，我们将获得对这种具有全球意义的物种的新见解：我们将通过实验探索Undaria对变化的环境参数（温度、辐射和营养）的反应，并利用这些信息预测其未来在欧洲水域的生物入侵能力。与此同时，将利用这一信息改进其原生地的水产养殖技术。我们将在青岛和不来梅的实验室进行协调实验，研究青岛和欧洲最北部的Undaria种群的标本的光合作用，生长，繁殖等日常生态生理过程。我们将研究环境变化对重要生理生化参数的影响，如色素和脂肪酸组成、抗氧化电位、绿单宁合成。在这项研究中，我们将包括Undaria的所有不同的生活史阶段。我们将进一步比较各自的群体在两个站点应用最先进的技术在群体遗传学。最后，我们将获得关于范围扩大机制的新见解，这同时将允许在欧洲水域对入侵者采取更好的保护措施，并有可能提高产量，并允许在中国沿海进行更可持续的种植（即通过减少肥料释放）。

The Asian kelp Undaria pinnatifida represents a seaweed species, which is extensively cultivated as food source in Chinese coastal waters and plays an important role in human nutrition in China and Japan ("wakame" in Japan, "qundaicai" in Chinese). Undaria is usually raised in mariculture facilities, where environmental perturbation and potentially overstocking might reduce the annual yield. At the same time, outside its native distributional range U. pinnatifida represents a rapidly spreading invasive species, with the potential to outcompete the respective native marine flora. It´s northern distributional limit in European waters is currently at the Dutch coastline and a further spread into the German Bight is to be expected soon. By the cooperation of a Chinese and German research team, which are both renowned in the field of seaweed biology, new insights will be gained on this species of global significance: We will experimentally explore Undaria´s responses to changing environmental parameters (temperature, radiation and nutrients) and use this information to predict its capacity for future bioinvasion in European waters. In parallel this information will be implemented to improve aquaculture techniques in its native range. We will conduct coordinated experiments in the laboratories in Qingdao and Bremen studying housekeeping ecophysiological processes like photosynthesis, growth, reproduction on specimens from the Qingdao and the northernmost European population of Undaria. We will study the effect of environmental changes on important physiological/biochemical parameters like pigment and fatty acid composition, antioxidative potential, phlorotannin synthesis. In this study we will include all different life-history stages of Undaria. We will furthermore compare the genetic identity of the respective population at both sites applying state-of-the-art techniques in population genetics. Conclusively we will gain new insights into the mechanisms of range expansion, which at the same time will allow for better protection measures against the invader in European waters and potentially improve yield and allow for a more sustainable cultivation (i.e. by less fertilizer release) along the coast of China.