Current meter for larval and benthic ecology

在这项提案中，我们要求提供资金，以购买一种可以测量不同深度水流的仪器。Metaxas的研究重点是生活在海底的无脊椎生物种群，如海星，海胆，螃蟹，龙虾和贻贝，它们具有复杂的生命周期。作为成虫，它们在海底生活和觅食，但它们会产生幼虫，这些幼虫可能会在水中度过几个小时到几个月，被水流携带。幼体最终移动到海底附近，附着在海底，经过一系列形态和生理变化，变成幼体。这些幼鱼长成有生殖能力的成年鱼。返回成年种群的新补充数量将取决于在水柱中存活、迁移到海底并成功转变为幼鱼的幼鱼数量。拟议的研究将集中在影响幼虫和少年生存的因素，以及这些生活史阶段之间的过渡。了解在这些早期生命史阶段发生的过程对于成功管理无脊椎动物物种和渔业以及海洋保护区内种群的成功至关重要。目前的测量将被用来解释幼虫扩散的距离和方向。Scheibling的研究调查了海带床生态系统的周期性变化，这种变化是由海胆数量的波动引起的，海胆周期性地过度放牧海藻，创造了生物多样性和生产力低下的栖息地。在新斯科舍省，当浅水中的海胆因疾病而死亡时，海带床会恢复。在更深更冷的水域，海胆不受疾病的影响，并逐渐迁移到岸上，导致新的爆发。Scheibling的小组正在调查这些深海种群的范围，并将海胆丰度的模式与环境因素（如海底洋流）联系起来。这些生活在深海的海胆也可以是浅水海带床的重要幼虫来源，而浅水海带床又依赖于水流。海流和海洋条件也将决定海胆的水媒病原体的传播。

In this proposal, we request funds to purchase an instrument that can measure currents at different depths in the water. Metaxas's research focusses on populations of invertebrate organisms that live on the seafloor, such as sea stars, sea urchins, crabs, lobsters, and mussels, which have complex life cycles. As adults, they live and feed on the seafloor, but they produce larvae which may spend from a few hours to months in the water, being carried by currents. Larvae eventually move near the seafloor, attach to it and, following a sequence of morphological and physiological changes, turn into juveniles. These juveniles grow into reproductive adults. The number of new recruits that return to the adult populations will depend on the number of larvae that survive the period spent in the water column, migrate to the seafloor and transition successfully into juveniles. The proposed research will focus on factors that influence larval and juvenile survival, as well as the transition between these life history stages. Understanding the processes that occur at these early life history stages is important for the successful management of invertebrate species and fisheries, and the success of populations in marine protected areas. Current measurements will be used to interpret the distances and directions of larval dispersal. Scheibling's research investigates cyclical changes in kelp-bed ecosystems, arising from fluctuations in numbers of sea urchins that periodically overgraze seaweeds and create habitats with low biodiversity and productivity. In Nova Scotia, kelp beds recover when urchins in shallow water die-off due to disease. In deeper colder water, urchins are unaffected by disease and gradually migrate onshore resulting in renewed outbreaks. Scheibling's group is surveying the extent of these deep populations and relating patterns of urchin abundance to environmental factors, such as bottom currents. These deep-living urchins also can be an important larval source for shallow kelp beds, which in turn depends on water flow. Currents and oceanographic conditions will also determine the spread of the water-borne pathogen of urchins.