Biology subjects

Iwanaga, T.

Publications and source records attributed to Iwanaga, T..

5 recordsLinked to original sources

bioRxiv2026

CoralBlox: A computationally efficient coral model for decision support

Coral reef management under climate change is challenging due to data sparsity and high uncertainty, yet it is essential for informing conservation strategies. We present CoralBlox, a mechanistic discrete time coral ecology model with the explicit aim of supporting rapid scenario exploration and decision making. The model represents discretized distributions of five coral functional groups across configurable spatial scales while incorporating key ecological processes, including coral growth, reproduction, thermal adaptation, and responses to disturbances. Validation against observed data demonstrates that CoralBlox effectively captures major trends in coral cover dynamics across the Great Barrier Reef, particularly for bleaching-driven mortality and recovery patterns. While simplifying ecological complexities, the model maintains sufficient ecological realism to evaluate and compare the result of distinct management strategies. CoralBlox enables comprehensive assessment of potential management interventions with high computational efficiency and interoperability. The model's flexible architecture makes it extensible to coral ecosystems worldwide, providing valuable exploratory capability for reef management.

ecology↗

bioRxiv2026

Importance of depth refugia for reef resilience and intervention on the Great Barrier Reef under future climate change

Coral reefs globally face unprecedented threats from climate change, with the Great Barrier Reef (GBR) experiencing cumulative stressors and increasingly severe declines in coral cover from thermal stress events. Understanding drivers behind reef resilience to climate impacts is critical for conservation planning and intervention strategies. A scenario-based population modelling approach was adopted with larval connectivity dynamics and environmental factors to assess coral reef resilience across the GBR using projected conditions under five Global Climate Models (GCMs). Projected coral cover was analysed for each reefs ability to maintain positive carbonate production budgets under future conditions, using coral cover as a proxy. Larval connectivity patterns did not correlate with increases in maintenance of positive carbonate budgets. Instead, reef depth emerged as the primary predictor, with deeper reefs (>10m) benefitting from reduced thermal exposure. These findings suggest that depth is a tangible and pragmatic reef characteristic to consider in future intervention practices for coral reef restoration. These results have important implications for reef management, indicating that depth should be considered as a key variable in conservation planning to maximize coral survival under continuing climate change.

ecology↗

bioRxiv2025

Pathway diversity: a resilience metric sensitive to agency applied to a lake eutrophication problem

Measuring resilience has been a longstanding challenge in social-ecological research. While there are established resilience metrics, they often do not account for agency, which is crucial in social-ecological systems. Pathway diversity is a recent approach to measuring resilience that integrates systems thinking with individual-based elements, such as agency. According to this approach, resilience is larger if actors have more decision pathways and can maintain them over time. Here we measure resilience using pathway diversity within a lake eutrophication model to analyse (a) the extent to which it is sensitive to changes in agency and (b) its compatibility with more established resilience metrics. Our findings reveal that pathway diversity is sensitive to regime shifts and can provide early warnings of them. Through five policy decision-making scenarios, we then show how pathway diversity can capture constraints on decision makers capability and agency that affect the systems resilience. We find that higher pathway diversity is associated with greater capability of decision-makers to influence the system. Pathway diversity addresses a critical gap by incorporating agency into a resilience metric while remaining compatible with established metrics. This work shows the potential of pathway diversity to identify resilience-based policy implications.

ecology↗

bioRxiv2025

A rapidly closing window for coral persistence under global warming

Summary paragraphCoral reefs around the world are threatened by recurrent marine heatwaves causing mass coral bleaching and mortality1. Mitigating future warming impacts requires strategic management2 that adopts a long-term lens. Global analyses of projected heatwaves3,4 are critical for decision-making but how disturbance refugia, coral life-histories and adaptation interact with warming is unknown. Here, we simulate coral eco-evolutionary dynamics across >3,800 individual reefs of Australias iconic Great Barrier Reef under the current suite of climate projections5. We forecast a rapid coral decline before mid-century regardless of emissions scenario. Under the most likely warming6, corals may continue to decline throughout the century. However, corals may recover after mid-century provided that warming is sufficiently slow, allowing thermal adaptation to keep pace with temperature changes - as projected if warming does not exceed 2{degrees}C. Higher emission scenarios would drive most reefs to a near collapse. Future resilient reefs were mostly found in bleaching refugia, which also possessed a greater diversity of thermal phenotypes. Although cool-adapted corals disperse to thermal hotspots, there was no evidence of gene swamping undermining thermal adaptation. While opportunities exist to build management strategies that promote adaptation in thermal refugia and warm spots, curbing the rate of warming by 2050 is crucial for coral persistence.

ecology↗

bioRxiv2018

mitoNEET Regulates Mitochondrial Iron Homeostasis Interacting with Transferrin Receptor

Iron is an essential trace element for regulation of redox and mitochondrial function, and then mitochondrial iron content is tightly regulated in mammals. We focused on a novel protein localized at the outer mitochondrial membrane. Immunoelectron microscopy revealed transferrin receptor (TfR) displayed an intimate relationship with the mitochondria, and mass spectrometry analysis also revealed mitoNEET interacted with TfR in vitro. Moreover, mitoNEET was endogenously coprecipitated with TfR in the heart, which indicates that mitoNEET also interacts with TfR in vivo. We generated mice with cardiac-specific deletion of mitoNEET (mitoNEET-knockout). Iron contents in isolated mitochondria were significantly increased in mitoNEET-knockout mice compared to control mice. Mitochondrial reactive oxygen species (ROS) were higher, and mitochondrial maximal capacity and reserve capacity were significantly decreased in mitoNEET-knockout mice, which was consistent with cardiac dysfunction evaluated by echocardiography. The complex formation of mitoNEET with TfR may regulate mitochondrial iron contents via an influx of iron. A disruption of mitoNEET could thus be involved in mitochondrial ROS production by iron overload in the heart.

cell biology↗