The role of glass sponge reefs in nutrient cycling: inputs, outputs, and evidence of population changes through the millennia

在不列颠哥伦比亚省的浅沃茨，玻璃海绵形成了覆盖数百公里海底的密集珊瑚礁。海绵提供了一个独特的栖息地，商业上重要的岩鱼，但他们在当地的生态地球化学循环的作用尚未被探讨。目前正在考虑保护珊瑚礁免受拖网和其他捕鱼作业的影响，但它们作为附近其他生产力较低的栖息地的碳（食物）和硅（骨骼材料）来源的作用可能同等重要，如果不是更重要的话。 在拟议的工作中，将利用沉积物捕集器、岩心、水样和海绵样品中的脂肪酸和稳定同位素分析，追踪珊瑚礁下游的海绵“碳特征”。 这个特征将被用来追踪进入珊瑚礁的碳输入以及这些碳在被海绵处理后的命运。 硅的吸收率，这在历史上一直低于目前的方法的检测限，将整合随着时间的推移，使用一种新的方法，涉及染料PDMPO标记生长轮骨针。 最后，将利用综合大洋钻探计划在不列颠哥伦比亚省周围收集的沉积物岩心来检查这些珊瑚礁的坚固性和范围。 将本文提出的不同方法和新方法结合起来，将清楚地了解海绵礁在碳和硅循环中的作用，并有助于决策者就未来的海洋保护区作出决定。

Glass sponges form dense reefs covering hundreds of kilometers of seafloor in the shallow waters of British Columbia. The sponges provide a unique habitat for commercially important rockfishes, but their role in local biogeochemical cycling has not yet been explored. The reefs are under consideration for protection from trawling and other fishing operations, but their role as sources of carbon (food) and silicon (skeletal material) for other less productive habitats nearby may be of equal if not greater importance. In the proposed work, a sponge "carbon signature" will be traced downstream of the reefs using fatty acid and stable isotope analyses from sediment traps, cores, water samples, and sponge samples. This signature will be used to trace carbon inputs into the reefs and the fate of that carbon once it is processed by the sponges. Rates of silicon uptake, which have historically been below detection limits of current methods, will be integrated over time using a novel method involving the dye PDMPO to mark growth rings in spicules. Finally, the robustness and extent of these reefs will be examined using sediment cores collected around British Columbia by the Integrated Ocean Drilling Program. Combining the different approaches and novel methods proposed here will provide a clear picture of the role sponge reefs play in carbon and silicon cycling and will help inform policymakers for decisions on future marine protected areas.