A scuticociliate causes mass mortality of Diadema antillarum in the Caribbean Sea.

Echinoderm mass mortality events shape marine ecosystems by altering the dynamics among major benthic groups. The sea urchin Diadema antillarum, virtually extirpated in the Caribbean in the early 1980s by an unknown cause, recently experienced another mass mortality beginning in January 2022. We investigated the cause of this mass mortality event through combined molecular biological and veterinary pathologic approaches comparing grossly normal and abnormal animals collected from 23 sites, representing locations that were either affected or unaffected at the time of sampling. Here, we report that a scuticociliate most similar to Philaster apodigitiformis was consistently associated with abnormal urchins at affected sites but was absent from unaffected sites. Experimentally challenging naïve urchins with a Philaster culture isolated from an abnormal, field-collected specimen resulted in gross signs consistent with those of the mortality event. The same ciliate was recovered from treated specimens postmortem, thus fulfilling Koch's postulates for this microorganism. We term this condition D. antillarum scuticociliatosis.

Shifting away from the business-as-usual approach to research conferences.

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.

Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005.

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.

A vision for regular, rapid assessments of the tropical northwestern Atlantic's coral reefs / Una visión para evaluaciones periódicas y rápidas de los arrecifes de coral del Atlántico tropical noroccidental

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.