Isotopic evidence for dead fish maintenance of Florida red tides, with implications for coastal fisheries over both source regions of the West Florida shelf and within downstream waters of the South Atlantic Bight

摘要: Abstract Toxic Florida red tides of the dinoflagellate Karenia brevis have downstream consequences 500–1000 km spatial extent. Fish stocks, shellfish beds, and harmful algal blooms similar species occupy same continental shelf waters southeastern United States, amounting to economic losses more than 25 million dollars in some years. Under aegis Center for Prediction Red tides, we are now developing coupled biophysical models conditions that lead impacted coastal fisheries, from Panhandle Cape Hatteras. Here, a nitrogen isotope budget food web West (WFS) South Atlantic Bight (SAB) reaffirms diazotrophs initial nutrient source onset identifies clupeid fish as major recycled their maintenance. The recent WFS SAB during 1998–2001 indicates since prehistoric times Timacua Indian settlements along Georgia coast 1075, ∼50% nutrients required large >1 μg chl l −1 K. been derived nitrogen-fixers, with other half decomposing dead sardines herrings. During 2001, >90% harvest clupeids was by ichthyotoxic >10 μg chl l , rather fishermen. After usual summer 2006 2007, simulated subsequent fall exports September 2007 North Carolina replicate observations just ∼1 μg chl l on year. In contrast, earlier left behind off 2006, less physical export, instead 10-fold larger those 2007. Earlier, 55 kills were associated these between Tampa Naples. Yet, only six reported there With little export prey former year, computed nutrient-sated, fish-fed growth rates model’s dinoflagellates also satellite-observed daily increments maintenance compared smaller fish-starved decanted last few decades, has remained “prudent predator” clupeids, i.e. Spanish sardine, whereas humans overfished stocks both thread herring shad. Thus, future operational forecasts land falls durations Louisiana Carolina, well prudent management regional fisheries require consideration negelected losses, at intermediate trophic levels, predators. Some harvested but separately supported longer parallel diatom-based chain calanoid copepods, feeding zooplanktivores thence piscivore predators, while intersecting shorter tide dinoflagellates, poorly grazed turn harpactacoid copepods. distinct phytoplankton functional groups, different herbivores, zoophagous fishes, must all be formulated explicit state variables next set complex ecological models, cued satellite data driven nested circulation within an ecosystem-based paradigm commercial sport harvests biotic marine resources higher levels SAB.