Co-occurrence of dinoflagellate and cyanobacterial harmful algal blooms in southwest Florida coastal waters: dual nutrient (N and P) input controls

Abstract

During July 2006, 2 distinctly different harmful algal blooms (HABs), one dominated by the pelagic red tide dinoflagellates Karenia spp. and the other by the benthic cyanobacterium Lyngbya majuscula, occurred simultaneously in the coastal embayments surrounding Sanibel and Captiva Islands, Florida, USA. The co-occurring HABs were investigated using in situ bioassays with additions of nitrogen (N) and phosphorus (P) alone and in combination to assess nutrient controls of these 'dueling' toxin-producing species. Photosynthetic, biomass (chlorophyll a), and (in L. majuscula) nitrogen fixation responses to nutrient enrichment were examined over 4 d. Primary productivity in Karenia spp. was consistently stimulated by N additions, while P additions failed to show stimulation. When added in combination with N, P did not lead to additional stimulation above N alone. Similar patterns of chlorophyll a stimulation were observed. These patterns were observed at 2 d, after which the cells fell out of suspension. Nutrient stimulation of L. majuscula metabolic activities as well as biomass production was smaller and much slower, relative to controls, than responses observed in Karenia spp. After the demise of Karenia spp., L. majuscula was able to continue utilizing subsequent nutrient additions, and it responded most strongly to the N + P additions after 4 d. This study confirms previous estuarine and coastal studies that indicated that when non-N 2 -fixing HABs co-occur with N 2 -fixing cyanobacterial HAB species, both N and P inputs need to be carefully considered and, in all likelihood, controlled.KEY WORDS: Lyngbya · Karenia · Charlotte Harbor · Sanibel and Captiva Islands · Florida · Blooms · Nutrients Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 371: [143][144][145][146][147][148][149][150][151][152][153] 2008 species include the Florida red tide dinoflagellate Karenia brevis (Steidinger et al. 1998, Steidinger 2002, Vargo et al. 2008 and, among the cyanobacteria, the planktonic genus Trichodesmium and the benthic genus Lyngbya. While the origin of these bloomforming taxa (i.e. offshore, nearshore, estuarine) can vary substantially, there is good agreement that when these bloom species encounter nutrient-enriched conditions, growth and bloom intensity of many of these taxa may be enhanced (Paerl 1988, Lapointe 1997, Elmgren & Larsson 2001, Paerl & Fulton 2006. Accordingly, there is a great deal of concern about coastal nutrient enrichment associated with rapid rates of coastal development in Florida and elsewhere.During July 2006, 2 taxonomically and ecologically distinct harmful algal blooms (HABs), one comprised of planktonic Florida red tide dinoflagellates Karenia spp. and the other of the benthic filamentous cyanobacterium Lyngbya majuscula, co-occurred in the coastal embayments of Sanibel and Captiva Islands, on Florida's southwest coast (see Fig. 1). Both genera have been implicated in regional water quality, fisheries habitat, and human health probl...

Hurricanes, El Niño and harmful algal blooms in two sub-tropical Florida estuaries: Direct and indirect impacts

“…The exception to this trend in the St. Lucie Estuary is high rainfall periods associated with high discharges from Lake Okeechobee during intense freshwater HAB events in the lake, leading to freshwater HABs of allochthonous origin in the estuary 18,39 . Similar relationships have been observed in other estuaries 77 , such as the Caloosahatchee estuary in Florida 78 and San Francisco Bay 79 .…”

Uncovering cryptic diversity of Lyngbya: the new tropical marine cyanobacterial genus Dapis (Oscillatoriales)

“…Several studies have reported large blooms of Dapis pleousa (as Lyngbya majuscula ) in coastal locations around Florida, based on secondary metabolites analyses and/or limited molecular data (Capper and Paul , Paerl et al. , Capper et al. , Sneed et al.…”

“…The misidentification of these cryptic species is, however, understandable when a polyphasic molecular, chemical, and electron microscopy approach had not been applied until now. Several studies have reported large blooms of Dapis pleousa (as Lyngbya majuscula) in coastal locations around Florida, based on secondary metabolites analyses and/ or limited molecular data (Capper and Paul 2008, Paerl et al 2008, Capper et al 2016, Sneed et al 2017. Likewise, this species has also been reported from other locations in the Caribbean (e.g., Panama, Gutierrez et al 2010), Pacific (e.g., Hawaii, Cardellina et al 1979;Guam, Thacker et al 1997), and Indian Ocean (Madagascar, Singh et al 1999), suggesting that D. pleousa is an abundant, common, and widely distributed cyanobacterium in tropical marine environments as well as subtropical regions during warmer summer periods.…”

Interspecific Relationship and Ecological Requirements of Two Potentially Harmful Cyanobacteria in a Deep South-Alpine Lake (L. Iseo, I)

“…Regional and global warming, with an associated increase in temperature and variability in rainfall patterns, causes changes in nutrients, sediment delivery, sediment-water exchange and metabolism, water residence time, and vertical stratification [6,12]. Therefore, ecosystems are subjected to alterations that affect the biotic community, modifying the species composition with the invasion and the establishment of allochthonous populations of Cyanobacteria in freshwater ecosystems [4,15,16]. Lake Iseo should be classified as "warm monomictic", since winter water temperatures never drop below 4 °C.…”