Unprecedented Bloom of the Cyano Bacteria Aphanizomenon in A
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Unprecedented bloom of the cyano sources (MARN) offshore from La Pir- raya island was also available for analy- bacteria Aphanizomenon in a coastal sis. Samples from February 18th re- bay of El Salvador vealed the presence of a high density population (127 x 103 colonies L-1) of Cyanobacteria bloom in marine, fresh- larly around La Pirraya island (Fig. 1A- the cyanobacteria Aphanizomenon (Fig. water and estuarine ecosystems [1]. B; Supplementary material 1). Accord- 2). Colonies were counted since cells It is widely recognized that increased ing to the locals, this potential bloom were moderately disintegrated and nutrient inputs in waterbodies may en- had started on February 16th and dead difficult to indentify individually. This hance cyanobacterial growth, resulting clams belonging to the genus Anadara species of Aphanizomenon presented in harmful algal blooms [2-3]. In estua- were found along the coast of La Pir- filaments forming fascicle-like colonies rine systems, blooms are enhanced by raya Island during the bloom period that ranged from 99 to 698 µm in length factors such as excessive nutrient load- (Supplementary material 2). Concern and 46 to 257 µm in width. ing, increased surface water tempera- about the impacts from this bloom in- Water temperature ranged from ture, persistent water column stratifica- creased when four piglets, less than one 30.4 to 31.1°C, pH from 7.0 to 8.1 and tion, long water residence time, organic year old, showed signs of dizziness, Secchi disk depth from 2.0 to 2.3m. matter enrichment, and hydrodynamic disorientation and pupil dilation after Aphanizomenon is one of the most and salinity anomalies [4]. eating these dead clams washed ashore common bloom-forming cyanobacte- Several cyanobacterial species pro- La Pirraya island at low tide. These pig- ria reported to form blooms in brack- duce toxins, such as microcystins, nodu- lets subsequently died as they were not ish environments [3]and more recently larins, cylindrospermopsin, anatoxin-a, able to walk or swim when the tide rose anthropogenic modifications of aquatic saxitoxins, LPS, aplysiatoxins, and lyng- (Supplementary material 3). environments. However, this genus has byatoxins, which can affect humans and In response to this event, five sites not been previously reported in the animals. [5]. In El Salvador, cyanobacte- in Bahía de Jiquilisco (Fig. 1A) were brackish environments of El Salvador. rial blooms have only been reported in sampled on 19th by LABTOX-UES staff The genera Dolichospermum, Pseudana- freshwater ecosystems, and blooms in using a Van Dorn bottle and 20 µm phy- baena, Lyngbya, and Oscillatoria have estuarine environments are more com- toplankton net. Phytoplankton species been recorded in Bahía de Jiquilisco, monly caused by diatoms or dinoflagel- were quantified using the Utermöhl [8]. This event is the first first report of lates. method or a Sedgewick-Rafter chamber an Aphanizomenon bloom in the brack- In February 2019, green water dis- (depending on cell abundance). An ad- ish environments of El Salvador. coloration, possibly caused by an in- ditional water sample from February Despite of the high concentration of tense microalgal bloom, was reported 18th sampled by staff from the Ministry Aphanizomenon in the sample of Feb- in western Bahía de Jiquilisco, particu- of the Environment and Natural Re- ruary 18th, the genus was not detected Fig. 1. A. Location of La Pirraya Island and sampling point in Bahía de Jiquilisco, El Salvador. B. Sampling location in Bahía de Jiquilisco. C. Shore of La Pirraya Island, where four pigs died. 12 HARMFUL ALGAE NEWS NO. 62 / 2019 providing video ma- terial, the Secretary of Scientific Research from the University of El Salvador for logistic support, and the Min- istry of Environment and Natural Resources (MARN) for providing water samples. This work was funded by IAEA Project RLA7022 and by the “Network for the Investigation of marine coastal stress- ors in Latin America and the Caribbean Fig. 2. Aphanizomenon fascicles found in Bahía de Jiquilisco observed using an inverted micro- (REMARCO)” scope. Supplementary material Table 1. Most abundant phytoplankton genera and species This material was provided by NGO Tablefound 1. inMost Bahía abundant de Jiquilisco,February phytoplankton genera 19th, and2019. species found ProCosta and can be accessed in the fol- in Bahía de Jiquilisco,February 19th, 2019. lowing links: Cell abundance https://drive.google.com/drive/ Taxa (cells L‐1) folders/1HLgwp_d9JNhzQQYedVsQVCW OoYQONvn4?usp=sharing Coscinodiscus References Skeletonema costatum spp. 54,429 1. Codd G A et al 2005. In Harmful Cyano- bacteria, pp. 1–23 Pseudo‐nitzschia 44,363 2. Paerl H W & J Huisman 2018. Science Prorocentrum micans spp. 18,148 320: 57–58 3. Paerl H W & T G Otten 2013. Microb Ecol Tripos fusus 672 65(4): 995–1010 4. Paerl H W 1996. Phycologia 35: 25–35 Prorocentrum compressum 672 5. Codd G A 2000. Ecol Eng 16: 51–60 6. Espinoza J et al. 2013. Bioma :43–46 Tripos furca c.f. 336 7. Espinoza J et al 2013. Atlas de Fitoplanc- ton Marino. http://hab.ioc-unesco.org/ Dinophysis caudata 336 ANCA documents # 70 20 8. Cuéllar T del C & C G Rivera 2010. Uni- versidad de El Salvador, 2010, pp. 59–81 9. Ballot A et al. 2013. Appl Environ Micro- in the samples collected during Febru- since this genus has been reported to biol76(4) 1173–1180 ary 19th; suggesting the bloom lasted produce toxins such as cylindrosper- around three days. Table 1 shows the mopsin, anatoxin-a, and saxitoxins than Authors most abundant phytoplankton genera can cause hepatic and neurologic ef- Rebeca Quintanilla, Oscar Amaya & Jeniffer and species found at the five sampling fects on mammals [5, 9]. Although four Guerra, Laboratorio de Toxinas Marinas de la Universidad de El Salvador (LABTOX-UES) sites on February 19th. These species piglets died, there were several other Final Av. Héroes y Mártires del 30 de julio, were found in similar abundances in pigs (1.5 years old) nearby that ate San Salvador, El Salvador. previous reports from this area. dead molluscs but did not die, and signs It is most likely that the spring high of dizziness and disorientation they had E-mail corresponding author: tides that occurred during the night of exhibited disappeared with time. [email protected] February 18th washed away the bloom, This event highlights the need to since local inhabitants reported that af- monitor cyanobacteria blooms in El ter high tide they no longer saw water Salvador and the toxins produced by discoloration. Locals of La Pirraya also species within this group, since the cur- expressed they had never seen such rent national capability to study these type of bloom in the area before. blooms is low. Although toxicity was not meas- ured in tissues from the dead piglets, Acknowledgements it is suspected that the Aphanizomenon We thank the NGO ProCosta for their bloom was linked to their intoxication, support for the sampling campaign and HARMFUL ALGAE NEWS NO. 62 / 2019 13.