Perturbations in a pelagic food web during the NE pacific large marine heatwave and persistent harmful diatom blooms.

Unprecedented warm ocean conditions, driven by the Large Marine Heatwave (LMH) and the 2015-16 El Niño in the Northeast Pacific favored pervasive toxigenic Pseudo-nitzschia spp. blooms that caused widespread ecological impacts, but little is known about the magnitude to which marine food webs were altered. Here, we assessed the trophic transfer of domoic acid (DA; a neurotoxin) and changes in trophic position from multiple key species during the peak of the LMH and El Niño in 2015 in comparison with 2018, a reference non-anomalous warm year.

Molecular forecasting of domoic acid during a pervasive toxic diatom bloom.

In 2015, the largest recorded harmful algal bloom (HAB) occurred in the Northeast Pacific, causing nearly 100 million dollars in damages to fisheries and killing many protected marine mammals. Dominated by the toxic diatom , this bloom produced high levels of the neurotoxin domoic acid (DA). Through molecular and transcriptional characterization of 52 near-weekly phytoplankton net-tow samples collected at a bloom hotspot in Monterey Bay, California, we identified active transcription of known DA biosynthesis () genes from the three identified toxigenic species, including as the primary origin of toxicity.

Molecular Forecasting of Domoic Acid during a Pervasive Toxic Diatom Bloom.

Unlabelled: In 2015, the largest recorded harmful algal bloom (HAB) occurred in the Northeast Pacific, causing nearly 100 million dollars in damages to fisheries and killing many protected marine mammals. Dominated by the toxic diatom , this bloom produced high levels of the neurotoxin domoic acid (DA). Through molecular and transcriptional characterization of 52 near-weekly phytoplankton net-tow samples collected at a bloom hotspot in Monterey Bay, California, we identified active transcription of known DA biosynthesis ( ) genes from the three identified toxigenic species, including as the primary origin of toxicity.

Dinoflagellate vertical migration fuels an intense red tide.

Harmful algal blooms (HABs) are increasing globally, causing economic, human health, and ecosystem harm. In spite of the frequent occurrence of HABs, the mechanisms responsible for their exceptionally high biomass remain imperfectly understood. A 50-y-old hypothesis posits that some dense blooms derive from dinoflagellate motility: organisms swim upward during the day to photosynthesize and downward at night to access deep nutrients.

A marine protected area network does not confer community structure resilience to a marine heatwave across coastal ecosystems.

Marine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014-2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States.

A cross-regional examination of patterns and environmental drivers of Pseudo-nitzschia harmful algal blooms along the California coast.

Pseudo-nitzschia species with the ability to produce the neurotoxin domoic acid (DA) are the main cause of harmful algal blooms (HABs) along the U.S. West Coast, with major impacts on ecosystems, fisheries, and human health.

Development, calibration, and evaluation of a model of Pseudo-nitzschia and domoic acid production for regional ocean modeling studies.

Pseudo-nitzschia species are one of the leading causes of harmful algal blooms (HABs) along the western coast of the United States. Approximately half of known Pseudo-nitzschia strains can produce domoic acid (DA), a neurotoxin that can negatively impact wildlife and fisheries and put human life at risk through amnesic shellfish poisoning. Production and accumulation of DA, a secondary metabolite synthesized during periods of low primary metabolism, is triggered by environmental stressors such as nutrient limitation.

Stable isotope analysis reveals differences in domoic acid accumulation and feeding strategies of key vectors in a California hotspot for outbreaks.

Given the effects of harmful algal blooms (HABs) on human and wildlife health, understanding how domoic acid (DA) is accumulated and transferred through food webs is critical for recognizing the most affected marine communities and predicting ecosystem effects. This study combines stable isotopes of carbon (δC) and nitrogen (δN) from bulk muscle tissue with DA measurements from viscera to identify the foraging strategies of important DA vectors and predators in Monterey Bay, CA. Tissue samples were collected from 27 species across three habitats in the summer of 2018 and 2019 (time periods without prominent HABs).

Reimagining the potential of Earth observations for ecosystem service assessments.

The benefits nature provides to people, called ecosystem services, are increasingly recognized and accounted for in assessments of infrastructure development, agricultural management, conservation prioritization, and sustainable sourcing. These assessments are often limited by data, however, a gap with tremendous potential to be filled through Earth observations (EO), which produce a variety of data across spatial and temporal extents and resolutions. Despite widespread recognition of this potential, in practice few ecosystem service studies use EO.

A Time Series of Water Column Distributions and Sinking Particle Flux of and Domoic Acid in the Santa Barbara Basin, California.

Water column bulk abundance and the dissolved and particulate domoic acid (DA) concentrations were measured in the Santa Barbara Basin (SBB), California from 2009⁻2013 and compared to bulk cell abundance and DA concentrations and fluxes in sediment traps moored at 147 m and 509 m. abundance throughout the study period was spatially and temporally heterogeneous (<200 cells L to 3.8 × 10⁶ cells L, avg.

Initial skill assessment of the California Harmful Algae Risk Mapping (C-HARM) system.

Toxic algal events are an annual burden on aquaculture and coastal ecosystems of California. The threat of domoic acid (DA) toxicity to human and wildlife health is the dominant harmful algal bloom (HAB) concern for the region, leading to a strong focus on prediction and mitigation of these blooms and their toxic effects. This paper describes the initial development of the California Harmful Algae Risk Mapping (C-HARM) system that predicts the spatial likelihood of blooms and dangerous levels of DA using a unique blend of numerical models, ecological forecast models of the target group, Pseudo-nitzschia, and satellite ocean color imagery.