Closing the Coral Life Cycle: A service blueprint to overcome the coral recruitment crisis through research, restoration, and innovation

This is a Preprint and has not been peer reviewed. This is version 2 of this Preprint. You must log in to post a comment. There are no comments or no comments have been made public for this article. This is a Preprint and has not been peer reviewed. This is version 2 of this Preprint. Add a Comment You must log in to post a comment. Comments There are no comments or no comments have been made public for this article. Coral reefs underpin marine biodiversity and the functioning of oceanic ecosystems, yet since the 1970s they have experienced unprecedented degradation, with the Caribbean region exhibiting some of the most acute declines. Global climate change—through warming, acidification, and intensified storm activity—combined with local stressors such as sedimentation, eutrophication, and over‑exploitation, now impedes every stage of the coral life cycle and has precipitated a chronic failure of sexual recruitment in the region’s dominant reef‑building taxa. In this synthesis we (i) delineate the complete life cycle of Caribbean reef‑building corals, (ii) identify the known principal barriers that prevent successful transition from gamete to recruit, and (iii) evaluate the suite of mitigation and restoration strategies currently available. We highlight interventions that (a) curb greenhouse‑gas emissions, (b) protect habitats from sediment and pollutant influx, (c) enhance adult colony health through targeted feeding and probiotic applications, (d) preserve genetic diversity via assisted gene flow, and (e) increase adult density and improve settlement substrate quality. Our review also exposes critical knowledge gaps that hinder the development of effective strategies to overcome barriers to coral recruitment: (1) the historical trajectory of recruitment failure, (2) species‑specific, quantitative in‑situ recruitment data, (3) reliable, low‑cost methods for determining colony age, (4) robust tracking of larval dispersal and supply, (5) the dynamics of symbiont availability and uptake, (6) identity and fine‑scale measurements of pollutants, and (7) disentangling the interactive effects of multiple stressors on early‑life stages. To bridge these gaps we propose a research agenda that integrates (i) inexpensive age‑dating techniques, (ii) rapid diagnostic and standardized stress‑assay platforms, (iii) next‑generation sensors for contaminant detection, (iv) molecular tools for symbiont identification, and (v) coupled biophysical‑eRNA methods to quantify larval transport and settlement. Finally, we present a service‑blueprint that aligns reef managers, scientists, restoration practitioners, and funders around coordinated decision‑making pathways for research prioritisation, restoration design, and investment allocation. Implementing this blueprint will accelerate our mechanistic understanding of coral recruitment, enable evidence‑based mitigation of global change impacts, and ultimately safeguard the persistence of Caribbean coral reefs. https://doi.org/10.32942/X2B348 Life Sciences Coral life cycle, sexual recruitment, conservation, climate change, local factors, human activities, knowledge gaps, research directions. Published: 2025-09-07 16:10 Last Updated: 2025-09-07 16:11 CC-By Attribution-NonCommercial-NoDerivatives 4.0 International Conflict of interest statement: None Data and Code Availability Statement: Not applicable Language: English