Testing the most striking tropical marine biodiversity gradient on the planet: does it hold for sponges?

珊瑚礁是地球上物种最丰富的生态系统之一，仅占海底的1%左右，但拥有已知海洋生物多样性的四分之一以上。珊瑚礁有时被称为海洋的热带雨林，具有巨大的内在生物、文化和经济价值。地球上近10亿人依赖珊瑚礁生态系统作为其重要的饮食来源，珊瑚礁每年的经济效益估计约为9.9万亿美元。因此，自20世纪80年代以来，全球珊瑚礁的数量估计减少了30%-50%，这是一个相当令人担忧的问题，因为科学家们正在努力了解物种是否在被发现之前就已经消失了。虽然珊瑚礁的多样性令人惊叹，但大多数生物多样性实际上隐藏在珊瑚礁本身的三维框架中。对这种隐藏的(或神秘的)生物群落的研究严重不足，而且对珊瑚礁的持续存在至关重要。在珊瑚礁中的这些神秘生物中，海绵是占主导地位的一组生物，它们从食物链的底部提供食物，并帮助维持珊瑚礁的生物多样性。尽管海绵在珊瑚礁上发挥着重要的生态作用，但人们对其多样性、丰富性或整个印度-太平洋地区的物种范围知之甚少。例如，地球上最引人注目的海洋生物多样性梯度是由珊瑚礁上几个明显占优势的群体描述的，包括珊瑚和珊瑚鱼。从印度-太平洋珊瑚三角物种丰富的全球热点，物种数量向东急剧下降，转向中太平洋更偏远的海洋岛屿，如夏威夷群岛。然而，到目前为止，还没有一项调查评估过鲜为人知的神秘珊瑚礁物种的多样性，如海绵，是否表现出与主导珊瑚礁表面的可见物种相同的模式。夏季培训单元将面临风险的太平洋岛民青年介绍给珊瑚礁生物多样性，以招募和培训新一代海绵分类学家。正在编制识别指南，以帮助资源管理人员建立海绵多样性基线，使资源管理人员能够识别和保护本地物种，改进对外来物种引进的检测，并作为监测生态系统因应人类影响而发生变化的工具。这项工作正在通过科学文献、公开和专业演讲、受欢迎的新闻文章以及与WAIKīkī水族馆合作的关于海绵和珊瑚礁生物学的教育展示得到广泛传播。通过分析从整个太平洋收集的现有积压的标准化采样设备(ARM)来确定生活在珊瑚礁框架内的基本上看不到的海绵是否遵循以前报告的鱼类和珊瑚的多样性梯度，来弥补这一重要的知识差距。通过将分类学与多位点DNA条形码和元生物编码相结合，该项目正在记录跨越热带太平洋10,000公里的五个生态区的神秘海绵群落中的物种丰富度和生物多样性格局。这些收集包括许多新物种，并为现有的参考数据库提供有凭证的DNA条形码，这些参考数据库目前包括全球不到1%的海绵物种。海绵是药物开发的丰富来源，因此新物种的发现也为从海绵及其相关可培养微生物中探索天然产品提供了机会。通过检查每个生态区环境和人为梯度上的海绵物种出现情况和多样性，数据还说明珊瑚礁海绵是否可以作为人类影响的指标。总的来说，这些结果正在改变我们对热带太平洋海绵生物多样性、物种范围的知识，并为全球序列数据库提供急需的参考条形码。通过确定海绵是否表现出与鱼类和珊瑚报告的相同的印度洋-太平洋丰富度梯度，该项目正在测试从生活在珊瑚礁表面的可见物种子集得出的概括如何适用于珊瑚礁生物多样性的其他部分。这项研究极大地促进了我们对太平洋珊瑚礁海绵的了解，并最终将揭示这种未被研究的分类群在整个太平洋发挥的重要生态作用的规模，例如食物链底部的营养物质的生产。该奖项反映了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。

Coral reefs are among the most species-rich ecosystems on the planet, occupying only about 1% of the seafloor, but housing more than a quarter of known marine biodiversity. Sometimes called the rainforests of the sea, coral reefs have great intrinsic biological, cultural and economic value. Nearly a billion people across the planet rely on coral reef ecosystems as a significant source of their diet, and the annual economic benefits of coral reefs are estimated to be around $9.9 Trillion USD. Thus, the global decline of coral reefs by an estimated 30-50% since the 1980s is of considerable concern as scientists struggle to understand whether species are being lost before they are even discovered. While coral reefs are spectacularly diverse, the majority of this biodiversity actually lives hidden deep within the three-dimensional framework of the reef itself. This hidden (or cryptic) community of organisms are both dramatically understudied and fundamentally important for the persistence of coral reefs. Sponges are a dominant group among these cryptic organisms within the reef which provide food from the bottom of the food chain and help sustain coral reef biodiversity. Despite the vital ecological role of sponges on coral reefs, little is known about their diversity, abundance or species ranges across the Indo-Pacific. For example, the most striking marine biodiversity gradient on the planet is described from several of the visibly dominant groups on coral reefs, including corals and reef fishes. From the global hotspot of species richness in the Indo-Pacific Coral Triangle there is a sharp eastward decline in species numbers to more remote oceanic islands in the Central Pacific, such as the Hawaiian Archipelago. However, no survey to date has evaluated whether the diversity of poorly known cryptic coral reef species, such as sponges, show the same pattern as the visible species that dominate the surface of the reef. Summer training modules introduce at-risk Pacific Islander youth to coral reef biodiversity to recruit and train a new generation of sponge taxonomists. Identification guides are being produced to help resource managers in establishing a baseline of sponge diversity, which allows resource managers to identify and protect native species, improves detection of alien species introductions and serves as a tool for monitoring changes in the ecosystem in response to human impacts. The work is being disseminated widely through scientific literature, public and professional presentations, popular press articles, and an educational display about sponges and coral reef biology in collaboration with the Waikīkī Aquarium.This important knowledge gap is addressed by analyzing an existing backlog of standardized sampling devices (ARMS) collected from throughout the Pacific Ocean to determine whether sponges that live largely unseen within the reef framework follow the same diversity gradient as has been previously reported for fish and corals. By integrating taxonomy with multi-locus DNA barcoding and metabarcoding, this project is documenting species richness and biodiversity patterns among the cryptic sponge community across five ecoregions spanning over 10,000 km of the tropical Pacific. These collections include many new species and are providing vouchered DNA barcodes to existing reference databases that currently include fewer than 1% of sponge species across the planet. Sponges are a rich source for pharmaceutical development, so discovery of new species also provides opportunity for exploration of natural products from both the sponges and culturable microbes associated with them. By examining sponge species occurrence and diversity along both environmental and anthropogenic gradients in each ecoregion, the data also address whether coral reef sponges can serve as indicators of human impacts. Collectively, these results are transforming our knowledge of tropical Pacific sponge biodiversity, species ranges, and providing much-needed reference barcodes to global sequence databases. By determining whether sponges show the same Indo-Pacific richness gradient as reported in fishes and corals, this project is testing how well generalizations made from the visible subset of species that live on the surface of coral reefs apply to rest of coral reef biodiversity. This study is greatly advancing our knowledge of Pacific coral reef sponges and will ultimately inform the scale over which vital ecological roles performed by this understudied taxon, such as the production of nutrients at the bottom of the food chain, are acting across the Pacific.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.