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The 1983-1984 die-off of the long-spined sea urchin Diadema antillarum stands out as a catastrophic marine event because of its detrimental effects on Caribbean coral reefs. Without the grazing activities of this key herbivore, turf and macroalgae became the dominant benthic group, inhibiting coral recruitment and compromising coral reef recovery from other disturbances. In the decades that followed, recovery of D. antillarum populations was slow to non-existent. In late January 2022, a new mass mortality of D. antillarum was first observed in the U.S. Virgin Islands. We documented the spread and extent of this new die-off using an online survey. Infected individuals were closely monitored in the lab to record signs of illness, while a large population on Saba, Dutch Caribbean, was surveyed weekly before and during mortality to determine the lethality of this event. Within four months the die-off was distributed over 1,300 km from north to south and 2,500 km east to west. Whereas the 1983-1984 die-off advanced mostly with the currents, the 2022 event has appeared far more quickly in geographically distant areas. First die-off observations in each jurisdiction were often close to harbor areas, which, together with their rapid appearance, suggests that anthropogenic factors may have contributed to the spread of the causative agent. The signs of illness in sick D. antillarum were very similar to those recorded during the 1983-1984 die-off: lack of tube feet control, slow spine reaction followed by their loss, and necrosis of the epidermis were observed in both lab and wild urchins. Affected populations succumbed fast; within a month of the first signs of illness, a closely monitored population at Saba, Dutch Caribbean, had decreased from 4.05 individuals per m2 to 0.05 individuals per m2. Lethality can therefore be as high as 99%. The full extent of the 2022 D. antillarum die-off event is not currently known. The slower spread in the summer of 2022 might indicate that the die-off is coming to a (temporary) standstill. If this is the case, some populations will remain unaffected and potentially supply larvae to downstream areas and augment natural recovery processes. In addition, several D. antillarum rehabilitation approaches have been developed in the past decade and some are ready for large scale implementation. However, active conservation and restoration should not distract from the primary goal of identifying a cause and, if possible, implementing actions to decrease the likelihood of future D. antillarum die-off events.

To combat the climate crisis, we need rapid, unprecedented social change. Scientists can play a lead role by signaling to society that we recognize the critical importance of redesigning our business-as-usual approach to research conferences. Traditional research conferences have high CO2 emissions as well as significant financial and travel time costs for participants. Using available technology, early career scientists Chelsie Counsell and Franziska Elmer created a global, virtual, coral reef research conference with live talks, recorded contributions, and networking events. Funding from The Company of Biologists allowed this event to be free, supporting attendance of 2700 subscribers and content contributions from 165 participants from diverse backgrounds and career stages. We provide metrics on content viewership and participation in networking activities, note the success of incorporating regionally focused sub-events, and discuss the emergence of a collaborative research project. We highlight the broad accessibility of virtual conferences as well as their increased flexibility in programming, health benefits, and cost savings. Our approach to organizing and hosting a global, low-carbon emission research conference is documented. Finally, we propose a hybrid approach to future conferences with virtually connected remote (sub-regional or local) hubs.

The Atlantic and Gulf Rapid Reef Assessment (AGRRA) Program, consisting of non-fixed, transect- based visual surveys, provides "snapshot" characterizations of a number of structurally or functionally important benthic and fish indicators on tropical northwestern Atlantic (TNWA) coral reefs and Brazil. To ameliorate the confounding factors inherent in multiyear temporal variation, a region-wide collaborative program for conducting rapid reef assessments at regular (five-year) intervals in sites that are representative of each sub-region of the TNWA is proposed. Member institutions of the Association of Marine Laboratories of the Caribbean (AMLC) and individual colleagues are invited to join in developing the vision. Rev. Biol. Trop. 54 (Suppl. 3): 23-29. Epub 2007 Jan. 15.El Programa de Evaluación Rápida del Atlántico y el Golfo (AGRRA, por sus siglas en inglés) consiste en sondeos visuales no-fijos, basados en transectos, que permiten caracterizaciones puntuales de un número de peces y organismos bénticos que sean estructural o funcionalmente importantes como indicadores en arrecifes del Atlántico tropical noroeste (ATNO) y de Brasil. Para disminuir los factores de confusión inherentes a variaciones temporales multianuales, se propone un programa de colaboración a nivel regional, que sirva para conducir evaluaciones rápidas de los arrecifes en intervalos regulares (cinco años), en los sitios que sean representativos de cada sub-región del ATNO. Se invita a las instituciones miembro de la Asociación de Laboratorios Marinos y del Caribe (ALMC), así cómo a colegas individuales para participar en el desarrollo de esta visión.

BACKGROUND: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.