Environmental consequences of expanded recruitment of an ecosystem engineer on a hypoxia-influenced continental shelf

高产的美国西海岸渔业物种和海洋哺乳动物依靠底栖无脊椎动物群落作为食物。然而，这些社区正在发生变化。该项目探讨了一个新成员对这些底栖群落的潜在生态后果，即幽灵虾新锥虫。在河口，新台虫通过它们的洞穴活动不断地对沉积物进行再加工。高丰度的虾和穴居的影响相结合，减轻了营养流失(自然和人为造成的)的影响，这可能会加剧低氧条件。然而，新锥虫也被认为是对牡蛎产业的威胁，因为它们的沉积物挖掘活动。它们的分布范围扩大到河口以外，可能会对敦刻尼斯蟹渔业产生额外的意想不到的后果(区域价值为每年3300万-7400万美元)，因为新锥虫既是幼蟹的竞争对手，也是更大的敦刻尼斯蟹的猎物。因此，需要新的数据来确定近海底栖动物群落是如何因新台虫重新进入新的栖息地而改变的。这项研究比较了虾丰度高和低的群落，以了解它们对近海底栖生物群落的影响。这种虾对氧气和碳循环的贡献是通过实地测量来估计的。底栖群落评估正在量化这些相对较大的虾的存在对海底食物资源造成的变化。俄勒冈州-华盛顿州大陆架沿岸水域具有商业价值，但它们也受到越来越多与人类有关的影响。可持续管理要求优化采掘、文化和娱乐活动。这项研究的更广泛影响包括管理者、商业渔业利益攸关方和牡蛎养殖者的关键数据，这些数据为有关海洋利用规划和洞穴虾管理的决策提供了信息。该项目为三名研究生和两名暑期本科生提供研究性培训。小学生课程开发的重点是软底栖动物的生态。西海岸的K-12年级学生通常更熟悉潮间带和海藻森林系统，他们通常对海洋沙质/泥泞的底栖生物一无所知。俄勒冈州、华盛顿州海岸和其他地方陆架水域不断变化的环境条件包括日益频繁和严重的缺氧事件、海洋酸化和变暖。这些变化影响了生物群落，改变了物种分布。洞穴幽灵虾(Neotrypaea sp.)的丰富中架种群在2015年海洋热浪之后的大陆架水域被记录下来。Neotrypaea是生态系统工程师，以前已知它们在潮间带河口泥滩中大量存在，而在开阔海洋中的存在微不足道。在河口，新台虫通过它们的洞穴活动不断地对沉积物进行再加工。由于洞穴灌溉，对虾可以增加氧气循环，并减少营养负荷的影响，如低氧条件。然而，与新锥虫相关的底栖生物耗氧量增加。床可能会加剧局部缺氧，从而对大陆架产生相反的影响。这项研究用生境适宜性模型方法描述了与新台虫扩大分布相关的环境条件。通过盒子取心和视频着陆器观测，模型预测正在通过广泛的现场采样得到验证。此外，底栖生物样本记录了新台胞菌床内底栖无脊椎动物群落的变化，以及这如何潜在地影响生物相互作用。对有和没有大量虾的大陆架区域的水生涡动协方差和岩心孵化的分析正在提供对虾对底栖氧通量和有机碳循环的贡献的估计。这些数据正被用来量化虾及其洞穴对相对于参考区的陆架中底栖动物总体生产力的影响。NeoTrypaea如何改变海底结构和生物地球化学需要进行表征，以预测这些生态系统工程师对较高营养水平和渔业的食物供应的影响。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Highly productive US West Coast fishery species and marine mammals rely on benthic invertebrate communities for food. However, these communities are changing. This project addresses the potential ecological consequences of a new member to these benthic communities, the ghost shrimp Neotrypaea. In estuaries, Neotrypaea continuously rework the sediment via their burrowing activities. The combination of high shrimp abundances and the effects of burrowing mitigate the impacts of nutrient run-off (natural and human-induced) that can exacerbate low oxygen conditions. However, Neotrypaea are also considered threats to the oyster industry because of their sediment-excavating activities. An expansion of their distribution beyond estuaries may have additional unforeseen consequences for the Dungeness crab fishery (regionally valued at $33-74M/y) as Neotrypaea are both competitors with juveniles and prey for larger Dungeness crab. Thus, new data are needed to determine how offshore benthic communities are being altered by the recruitment of Neotrypaea into new habitats. This study is comparing communities with high and low shrimp abundances to understand their impact on offshore benthic communities. The shrimp’s contributions to oxygen and carbon cycling are being estimated through field measurements. Benthic community assessments are quantifying changes to food resources on the seafloor caused by the presence of these relatively large shrimp. The coastal waters along the Oregon-Washington shelf are commercially valuable, yet they are also subject to growing human-related impacts. Sustainable management requires optimizing extractive, cultural, and recreational activities. The broader impacts of this research include key data for managers, commercial fisheries’ stakeholders and oyster growers that inform decisions regarding ocean-use planning and management of burrowing shrimp. This project is providing research training for three graduate students and two summer undergraduate students. Curriculum development for elementary school students is focused on the ecology of soft-bottom benthos. The ocean sandy/muddy benthos are often unknown to K-12 students on the West Coast who are usually more familiar with intertidal and kelp forest systems.Changing environmental conditions in shelf waters along the Oregon and Washington coasts and elsewhere have included increasingly frequent and severe hypoxia events, ocean acidification, and warming. These changes have affected biological communities and altered species distributions. An abundant mid-shelf population of the burrowing ghost shrimp, Neotrypaea sp. was documented in shelf waters following the Marine Heat Wave of 2015. Neotrypaea are ecosystem engineers that were previously known to be abundant in intertidal estuary mudflats with an insignificant presence in the open ocean. In estuaries Neotrypaea continuously rework the sediment via their burrowing activities. The shrimp can increase oxygen cycling due to burrow irrigation and reduce impacts of nutrient loading such as low-oxygen conditions. However, enhanced benthic oxygen consumption linked to Neotrypaea sp. beds could have the opposite effect on the shelf by intensifying regional hypoxia. This study is characterizing the environmental conditions associated with the expanded distribution of Neotrypaea using a habitat-suitability modeling approach. Model predictions are being validated through extensive field sampling via box coring and video lander observations. In addition, the benthic samples are documenting changes in the benthic invertebrate communities within the Neotrypaea beds and how this is potentially affecting biological interactions. Analyses of aquatic eddy covariance and of core incubations in shelf areas with and without abundant shrimp are providing estimates of the shrimp’s contribution to benthic oxygen fluxes and organic carbon cycling. These data are being used to quantify the shrimp’s and their burrows’ effects on the overall productivity of the mid-shelf benthos relative to reference areas. How Neotrypaea alter seafloor structure and biogeochemistry need to be characterized to predict the impact of these ecosystem engineers on the food supply for higher trophic levels and fisheries.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.