Project 3 - Projecting Ross Sea Ecosystem Changes in a Warming World
The Ross Sea region contains one of the most productive marine ecosystems in the Southern Ocean, encompassing open ocean, pack ice, and coastal habitats, including much of the world’s largest marine protected area. It also harbours diverse land-based ecosystems ranging from iconic Antarctic lakes to ancient soils that house many unique biota.
Why this research project, and what do we plan to do?
There are wide gaps in understanding of the drivers of terrestrial and coastal marine biogeography, as well as pelagic food web variability. Filling these gaps is vital for determining the consequences of environmental change on the biodiversity, biogeography (spatial extent) and ecological processes of Antarctic communities in a +2°C (Paris Agreement), or warmer, world.
Research Questions
- How can we expect the distribution of organisms to change in a +2 world?
- How vulnerable are food webs to changes in sea ice dynamics and ocean circulation?
- What are the consequences of these changes for ecosystem integrity?
Research Hypotheses
- Shifts in terrestrial and coastal marine biogeography will be driven by changes in the distribution of suitable habitats in a warmer climate, moderated by constraints on productivity, connectivity, biotic interactions, and taxa flexibility in response to change.
- In a warming world, pelagic food webs in the Ross Sea will be fundamentally altered due to spatial and temporal changes in primary production and loss of habitat for sympagic organisms.
Research Activities
- use new and existing data to describe and model how key features of Ross Sea Region ecosystems (species distribution, habitat utilisation, primary productivity, food webs, connectivity) are driven by the environment
- link ocean and sea ice processes to primary productivity and the processes that deliver this production to silverfish and krill, which provide a critical link to fish, penguins, and whales in the Ross Sea food web
- allow projections of environmental change (such as changes in sea ice conditions, increased melting of glaciers, altered ocean dynamics, and warming of regional climate) to project risks to ecosystem integrity
- establish long-term ecological research sites at selected locations along the Victoria Land coast
Objective 1: Climate Effects on Terrestrial Habitats and Biogeography
Objective Leaders: Charles Lee & Marwan Katurji
Goal: to determine factors affecting the past and current productivity and performance of terrestrial species, as well as the distribution of habitats and connectivity among them
Research Activities
- compile data products of known terrestrial taxa distribution and synthesised knowledge of biological and ecological processes for the Ross Sea Region
- identify the relationships between taxa distribution and current environmental constraints, highlighting physical and genetic connectivity, inferring potential historic refugia, and understanding the impacts of previous dispersal barriers
- develop surface meltwater generation and hydrological routing model simulations that incorporate dynamically downscaled projections of regional climate in a warming world
- identify data-poor locations for targeted field research to iteratively enhance biogeographic models
- establish a network of “sentinel sites”, where the greatest change is expected, across the Ross Sea Region
Objective 2: Coastal Marine Biogeography and Ecosystem Processes
Objective Leaders: Miles Lamare & Vonda Cummings
Goal: to improve baseline knowledge of benthic (nearshore) biodiversity, biogeography and key processes underpinning distributional patterns and ecosystem function in Victoria Land coastal habitats
Research Activities
- compile existing information on species distribution, habitats, and environmental characteristics for coastal marine benthic communities (0-300 m depth)
- undertake targeted fieldwork (fast ice-based sampling techniques and ship-based sampling) to expand depth and spatial coverage, especially to include less well sampled locations in Northern Victoria Land
- investigate biological processes and key drivers on the interconnectedness of existing Ross Sea benthic populations
- develop a framework for projecting impacts of a warming world on coastal biogeography and biodiversity
- establish sentinel sites, species, and communities to form the foundation of a focused, long-term costal monitoring programme
Objective 3: Pelagic Productivity and Food Webs
Objective Leaders: Matt Pinkerton & Helen McDonald
Goal: to understand how changes to oceanographic and environmental conditions on the Ross Sea continental shelf will drive “bottom-up” spatial and temporal variability in the pelagic (open ocean) primary productivity, food web and the sympagic community.
Research Activities
- fill research gaps on sympagic-ocean ecological connectivity by investigating the physical environment of marginal sea ice and the biological components and ecological relationships that drive its productivity
- develop semi-automated methods (based on DNA and acoustic techniques) to measure zooplankton and mesopelagic communities from research vessels, moorings and ships of opportunity
- measure and characterise the highly diverse zooplankton and mesopelagic communities in the Ross Sea Region
- couple biogeochemical model to existing hydrodynamic models to enable investigation of the drivers underpinning spatial and temporal variation in primary production and pelagic food webs
- detect large-scale patterns of ecosystem change, with special focus on keystone species
Objective 4: Projection of Ecosystem Responses and Bioregionalisation
Objective Leaders: Fraser Morgan & Crid Fraser
Goal: to develop and validate models that better project the likely biodiversity, biogeography and ecosystem function responses to anticipated environmental change in the Ross Sea Region.
Research Activities
- employ a hybrid biogeographic modelling approach, accounting for process-based species distribution
- predict the biogeography of Ross Sea Region terrestrial and coastal marine ecosystems as the Ross Sea Region changes
- analyse spatial and temporal variability in primary production, food web structure and energetics across the Ross Sea Region
- identify the sensitivity and vulnerability of a top-predator example to projected climate change
- identify plausible dispersal mechanisms and pathways for key taxa, and determine how warming will impact biogeographic patterns across the Ross Sea Region
- develop a biology-driven and climate-responsible bioregionalisation framework to make informed decisions around environmental protection
