Sponge functional roles in a changing world.

Sponges are ecologically important benthic organisms with many important functional roles. However, despite increasing global interest in the functions that sponges perform, there has been limited focus on how such functions will be impacted by different anthropogenic stressors. In this review, we describe the progress that has been made in our understanding of the functional roles of sponges over the last 15 years and consider the impacts of anthropogenic stressors on these roles. We split sponge functional roles into interactions with the water column and associations with other organisms. We found evidence for an increasing focus on functional roles among sponge-focused research articles, with our understanding of sponge-mediated nutrient cycling increasing substantially in recent years. From the information available, many anthropogenic stressors have the potential to negatively impact sponge pumping, and therefore have the potential to cause ecosystem level impacts. While our understanding of the importance of sponges has increased in the last 15 years, much more experimental work is required to fully understand how sponges will contribute to reef ecosystem function in future changing oceans.

Global status, impacts, and management of rocky temperate mesophotic ecosystems.

The ecology and function of rocky temperate mesophotic ecosystems (TMEs) remain poorly understood globally despite their widespread distribution. They typically occur at 20-150 m (the limit of photosynthesis), and on rocky substratum they support rich benthic communities and mobile fauna. We determined the distribution of rocky TMEs, their conservation status, and their most characteristic biological groups. Rocky TMEs were dominated by algae, turf-invertebrate matrices (<50 m only), sponges, bryozoans, and cnidarians. The community composition of TMEs differed significantly from shallow (0-15 m) subtidal reefs. Data were geographically biased and variable, available only from the North and South Atlantic, Mediterranean, and Temperate Australasia. Degree of protection of rocky TMEs varied considerably across the world. The biggest threats to rocky TMEs were identified changes in temperature, sedimentation rates, nutrient concentrations, and certain fishing types. We propose a conservation framework to inform future rocky TME management and conservation, highlighting the need to recognize the importance of these biologically diverse and functionally important ecosystems.

Resumen La ecología y la función de los ecosistemas mesofóticos templados (TME) rocosos todavía no están muy comprendidas a nivel mundial a pesar de su amplia distribución. Comúnmente se encuentran entre los 20 y los 150 metros (el límite de la fotosíntesis) sobre sustratos rocosos que mantienen comunidades bénticas diversas y fauna móvil. Determinamos la distribución, estado de conservación y grupos biológicos más característicos de los TME rocosos. Estos ecosistemas estuvieron dominados por algas, matrices de invertebrados de pastos marinos (solamente a <50 m), esponjas marinas, briozoos y cnidarios. La composición comunitaria de los TME difirió significativamente de los arrecifes submareales someros (0-15 m). Los datos estuvieron sesgados geográficamente y fueron variables, pues sólo estaban disponibles para el Atlántico norte y sur, el Mediterráneo y la Australasia templada. El nivel de protección de los TME rocosos varió considerablemente en todo el mundo. Las principales amenazas que enfrenta este ecosistema son los cambios en la temperatura, las tasas de sedimentación, la concentración de nutrientes y ciertos tipos de pesca. Proponemos un encuadre de conservación para orientar a futuro la gestión y conservación de los TME, el cual destaque la necesidad de reconocer la importancia de estos ecosistemas biológicamente diversos y funcionalmente importantes.