CLIOTOP task teams are formed to address specific research topics. Task teams are networks of researchers and are by nature open to collaboration and membership.
Proposals for new task teams can be submitted at any time to the CLIOTOP SSC, with calls and assessment of nomination being made at the end of each calendar year. Each proposal must address the following 6 questions:
- Who will be involved in the task team?
- What is being proposed by the task team and over what time period?
- What outputs or outcomes will be produced by the task team?
- How will outputs from the task team address CLIOTOP’s science questions?
- What resources are the task team expecting from CLIOTOP?
- How will those resources be used by the task team in achieving the expected outputs?
Task teams will be expected to provide a short report to CLIOTOP on their activities which can be posted on the CLIOTOP website and included in regular activity reports to IMBeR. Task teams are expected to identify their alignment with CLIOTOP in any publications arising from their activities and to provide copies of any publications for listing on the CLIOTOP and IMBeR websites.
Task Team 2023-2024: Exploring New Horizons, Barriers and Bottlenecks in Marine Ecological Forecasting for Oceanic Top Predators
Ecological forecasting seeks to predict ecological or ecosystem responses to physical variability and change over timescales relevant to the management of living resources. Applications of marine ecological forecasting are increasing in number, scope, geographic and taxonomic coverage, and management uptake. However, important challenges remain in addressing the barriers and bottlenecks in the process of developing and operationalising forecasts.
For example, producing skilful forecasts over seasonal-to-decadal forecast horizons, and accounting for the regionally varying limits of predictability are current challenges. Recent advances in physical and biogeochemical prediction systems have enabled skilful forecasts of ocean temperature, primary productivity, and chlorophyll-a up to 9 years into the future in some regions, providing new opportunities for the field of ecological forecasting.
In marine fisheries, much of the ecological forecasting effort to date has focused on predicting changes in the distributions of target species such as tuna and billfish, but less so on the potential of forecasting for mitigating fisheries-wildlife interactions with non-target species such as sharks, turtles, seabirds and marine mammals.
This Task Team aims to:
- share best practice to identify pathways for enhancing marine ecological forecasting capacity globally;
- explore the potential of ecological forecasting for mitigating fisheries-wildlife interactions with non-target species;
- scope the co-development of new regional forecasting applications.
Task Team 2023-2024: Global Analyses of White Shark Trophic Role
Task team leaders: C. Huveneers (Flinders University, Australia), L. Meyer (Flinders University, Australia), C. Lowe (California State University Long Beach, USA), G. Skomal (Massachusetts Division of Marine Fisheries, USA), O. Sosa-Nishizaki (Center for Scientific Research and Higher Education in Ensenada, Mexico), A. Towner (Rhodes University, South Africa)
White sharks, Carcharodon carcharias, have life history traits that result in the species having a low reproductive potential and unlikely to withstand extensive unnatural mortality. Therefore, anthropogenic impacts from targeted recreational fishing, bycatch in commercial fisheries, and catches in shark control program have led to global concerns about white shark population status, which prompted their protection across several national jurisdictions and international treaties. The predictable seasonal aggregations of white sharks in proximity to seal colonies, various shark mitigation programs (e.g. beach meshing), and iconic nature of the species has enable the collection of tissue samples at various locations around the globe from which biochemical tracers can be used to determine the ecological role and feeding ecology of white sharks.
Moving from regional-based trophic studies of top marine predators to a global-scaled comparative study of oceanic food web dynamics improves understanding of the trophic pathways that underlie the production of some pelagic predators in the open ocean, the movements of these predators, and the natural variability forced by the environment. Yet, no global analysis has been undertaken on the white shark, that occurs throughout the globe and across a broad range of ecosystems.
This task team will form an inclusive task team of trophic ecologists to undertake a global analysis of the trophic role and diet of white sharks by collating the existing fatty acid and stable isotope data from location-specific studies. The collated data will be analysed during a one-day trophic ecology workshop at the upcoming White Shark Global conference in Port Lincoln, South Australia. The specific analyses will depend on the dataset collated, but the task team will aim to address the following key ecological questions:
(a) consistency of ontogenetic changes in the ecological role of white shark across its distribution;
(b) comparison of isotope and fatty acid niche metrics (e.g. width and overlap) across white shark aggregation areas;
(c) multi-disciplinary approach to investigate spatio-temporal dynamics of white shark movements through the combination of tagging and biochemical tracer data (i.e., habitat use and coastal vs. pelagic feeding in relation to movements); and
(d) improve our understanding of what is driving the carbon production of white sharks.
Awareness of, and access to the large-scale global dataset will catalyse and facilitate new research to improve understanding of marine biology, food web ecology, and human impacts (such as fishing and climate change) on the environment.
Task Team 2023-2024: Investigating Global Micronekton Trophic Linkages in the Mesopelagic Zone
This task team continues in the international and collaborative tradition of previous Task Team 2017/01 (and CLIOTOP WG3), by examining the biogeochemical variability and trophic linkages of micronekton organisms in the global mesopelagic zone. Micronekton are small (~2-20 cm) swimming animals that span a diverse assemblage of fishes, crustaceans (mysids, amphipods, decapods), molluscs (cephalopods), and gelatinous taxa (ctenophores, siphonophores, medusae). Micronekton are a key ecosystem compartment in global pelagic ecosystems as they are the prey of numerous marine predators and are major actors in biogeochemical nutrient cycling, through the export and sequestration of carbon from diel vertical migrations that connect the surface ocean with depths down to 1,000 m and below.
We will use predictive models to conduct an inter-oceanic comparison of the biogeochemical tracers of abundant mesopelagic biota. We will use global coupled ocean circulation-biogeochemical models to account for known regional differences in food web baselines, to conduct large scale comparisons of micronekton isotopic trophic niche metrics (e.g., trophic positions, habitat usage patterns). Accounting for environmental parameters will aid in the examination of relationships between micronekton species and the environment at various spatial scales, better characterizing the global distribution of food web processes originating in the mesopelagic.
The primary outputs from this task team will consist of a global database of biogeochemical tracers (nitrogen and carbon stable isotopes, total mercury concentrations) from micronekton sampled in nearly all major ocean basins, alongside a scientific manuscript examining the global trophodynamics of this understudied community. As is feasible, we plan to examine these data alongside available top predator (tuna) data compiled from previous CLIOTOP efforts. We anticipate that the database will build on other existing databases (e.g., Mesoptroph, Myctobase), identify data gaps, and standardize data collection for diverse micronekton species. This work will facilitate future comparative analysis and research into mesopelagic food web structure and function, which is especially timely given the widely acknowledged impacts of global change that are underway (e.g., industrialized fishing, climate variability). Those interested in contributing data and participating in the work of this task team should contact Anaïs Mediéu and Anela Choy.
Task team 2023/01: The Climatic Impacts of Marine Heatwaves (MHWs) on Top Predators in the Tropical Oceans
Sustainable fishery industries are underlain by the principle of understanding the climatic impact on the fishery ecosystem. Top predators such as yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus), and skipjack (Katsuwonus pelamis) are critically important to the world’s fishing industry. However, those resources are threatened by oceanic biophysical drivers and global climate change. As a curial indicator of climate change, MHWs have key ecological effects on tuna distribution. MHWs and subsurface MHWs profoundly influence tuna fisheries. And we also want to know how it affects tuna communities and where would tuna go under the circumstance of high-frequency MHWs in the future. In order to figure out the impacts of MHWs on top predators and the way to improve the predictions of their spatial distribution, we set up a task team which will try to bring a better understanding of tuna. Our research is a deep interdisciplinary study with a new AI method. Our research will not only answer the key questions about top predators’ habitats, but also contribute to the United Nations’ Sustainable Development Goals (SDGs). We gather together with the same faith: bring a better understanding of the ocean’s living to life.
The task team will investigate the following broad areas:
- The biophysical effect of MHWs on tunas in tropical oceans.
- The effects of MHWs on the spatial habitat distribution of tuna species.
- Statistical and AI models that can identify key drivers and progresses of MHWs to tuna species.
- Indicators for tuna forecasting from the surface and subsurface MHWs signals.
Outputs will include:
- Research findings: clarified impacts of Marine Heatwaves (MHWs) and subsurface MHWs on top predators (especially tunas) in the tropical oceans under global climate change; prediction of fisheries distribution in new scenarios.
- Academic sharing: In order to let more scientists pay attention to some potential risks of tuna fisheries, we plan to share our research findings and tools in our publications.
- Data acquisition: Open access integrated dataset for tuna among followers and researchers will be established.
- International communication: organizing two to three international Zoom meetings, which are accessible to everyone interested in tuna and MHWs; providing an interdisciplinary platform for early career scientists.
- Public engagement: we will try to release news about our new findings and story posters in traditional and new media. And we will set up TEDx activities offline to tell our stories.