Benthic connections of high Southern Latitudes: BECOOL

• Grant number: 19/12551-8
• Support type: Research Program on Global Climate Change - Thematic Grants
• Duration: August 01, 2021 - July 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal researcher: Paulo Yukio Gomes Sumida
• Grantee: Paulo Yukio Gomes Sumida
• Home Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Pesquisadores principais: Vivian Helena Pellizari
• Assoc. researchers: Andres Omar Mansilla Muoz ; Christian Millo ; Craig Randalll Smith ; Kenneth M. Halanych ; Márcia Caruso Bícego ; Mônica Angélica Varella Petti ; Paulo Simionatto Polito ; Ricardo Rozzi ; Stefan Sievert

Abstract

Global changes are inducing significant alterations in the biosphere, such as changing animal migration behavior or expanding/reducing habitat size. Forecast changes to future ocean conditions are expected to follow similar patterns to those induced by present-day atmospheric phenomena, albeit at a slower rate. These cause significant alterations in organism distribution and consequent ecosystem function. Essentially, such changes will have global implications, significantly altering ocean currents, including those off the South American margin; and local effects, such as retracting glaciers. Differences in the biological complexity and evolutionary history between polar regions and other areas of the planet suggest stresses may distinctively affect ecosystem function in polar areas. Likewise, distinct taxa will probably have contrasting levels of resilience at different latitudes. It is expected that a series of biochemical, physiological and population stresses related to climate change will affect communities from the shelf to the deep sea. The Antarctic Peninsula is one of the most affected places on Earth undergoing unprecedented warming that is causing exaggerated ice shelf breakage and loss. Existing polar-related adaptations may restrain organismal responses to the rapid change occurring in the oceans. Antarctic communities are the reflection of a series of macro-evolutionary events, invasions, extinctions, tectonic processes and climatic changes that took place over a long geological time-scale. These time scales are the extremes of a continuum that shape fauna through the relative roles of ecological and evolutionary factors. This proposal aims to examine the existing benthic faunal links between the Antarctic and South America and the role of climate change (e.g., Polar Front shift and ice shelf loss) in current and future scenarios for high latitude marine benthic communities. To address these questions, we will study the benthic fauna from an intercontinental (Antarctica and South America) and local (Admiralty Bay) perspective, investigating its succession, structure and phylogeography. Using a global perspective, we will study the generalist and specialized fauna associated with organic falls by deploying (and retrieving) benthic "landers" containing organic substrata for colonization over time, placing them at strategic locations near and within the Drake Passage deployed in both shallow (~100 m) and deep waters (~1500 m) for a 1-year period. We will focus on the biota associated with organic falls (whale bones and wood parcels) on the continental margins of South America and Antarctica on the route of whale migratory paths and next to the extensive Magellanic subpolar forests. Locally, we will investigate the Martel inlet within the Admiralty Bay (King George Island), located in one of the most sensitive areas to climate change (ca. 10% of the area of glaciers were lost between 1979 and 2011) and where there is a wealth of meteorological, biological and environmental data available. We will investigate how benthic fauna recolonized these areas and compare with previous data available to understand the colonization and succession processes after glacier removal. Priority areas will be those where larger retractions were observed. Ecological, molecular and genetic approaches will establish regional and local diversity patterns, and the connectivity between the Antarctic and Magellanic populations and the role of the Polar Front and Circumpolar Antarctic Current as biogeographical barriers for organic fall fauna between these regions over the last 30 million years. Simultaneously, we will examine the trophic and ecosystem functions of these communities on the degradation of organic falls on the deep sea. These approaches will rely on a robust international partnership and on preterit data from the SW Atlantic, NE Pacific and Antarctica. (AU)