Table 1. Seawater physical and chemical parameters during the summer 2019 Chattonella bloom mg O2/L Nutrient concentration μM C Salinit y pH DO COD PO4 SiO4 NO2 NO3 NH4 35.00 17.8 8.64 6.3 22.5 13.35 58 12.6 20.6 45.2 TN SiO4 PO4 Table 2. Physical and chemical properties of seawater in the study area Parameter C Salinity pH DO DO% NO2 NO3 NH4 May 25,1 37,2 8,37 10,4 61,5 3 11,02 2,5 16,52 0,12 0,66 July 28,37 35,43 8,59 9,35 39,2 1,2 8,34 2,8 12,34 5,64 5,44 October 22,34 36,6 8,11 2,65 139,2 1,5 10,1 1,2 12,8 0,62 1 February 17,63 35,8 8,65 3,58 163,1 2,34 7,8 2,2 12,34 0,45 0,39 Mean 23,36 36,26 8,43 6,50 100,75 2,01 9,32 2,18 13,50 1,71 1,87 S.D. 4,54 0,80 0,24 3,94 59,71 0,82 1,50 0,69 2,02 2,63 2,39 Table 3. The abundance of Ostreopsis cf ovata attached to Chlorophyta, Rhodophyta and Phaeophyta macroalgae. May St. I St. II Macroalgae Cell g fw-1 % Cell g fw-1 % Chlorophyta Total 401.06 63.84 325.50 66.50 Mean 133.69 108.50 SD 102.06 88.71 Rhodophyta Total 227.19 10.15 164.00 9.35 Mean 75.73 54.67 SD 64.76 46.28 Phaeophyta Total 10.80 0.09 9.35 1.90 Mean 5.40 3.10 Standard Deviation 0.57 0.49 October St. I St. II Macroalgae Cell g fw-1 % Cell g fw-1 Rhodophyta Total 7.4 10.41 1.1 Mean 2.47 0.37 SD 3.67 0.46 % 1.55 Measurements of physical and chemical parameters at the sampling sites are given in Table 2. Salinity values didnt show a particular seasonal variation, and pH values were very stable. Dissolved oxygen levels in May and July were 3.5-3.9 times greater than the minimum in October. Nitrite concentrations exhibited the typical summer minimum, and it was highest in May. Nitrate concentrations were always high, and represented > 60% of the total estimated nitrogenous resources. Ammonia concentrations were often <3 μM, and reached a minimum in October. Silicate values were the lowest in May, with a maximum of 5.6 μM in July. Phosphate trends followed that of silicate. Abundance on the thalli of 14 differHARMFUL ALGAE NEWS NO. 63 / 2019 July Macroalgae Chlorophyta Total Mean SD Rhodophyta Total Mean SD February Macroalgae Rhodophyta Total Mean SD St. I St. II -1 -1 Cell g fw % Cell g fw % 60.49 20.16 24.11 9.63 38.10 12.70 17.07 7.78 12.77 6.39 4.08 2.03 8.70 4.35 3.26 1.78 Cell g fw % Cell g fw % 1.06 0.35 0.10 5.65 0.78 0.26 0.11 2.89 St. I St. II -1 -1 ent macroalgae species was estimated during a full year sampling. Analysis of variance showed significant differences in abundance between seasons and macroalgal hosts. Water temperature and nutrients (NO2-, NO3- and PO43-) seemed to be the major factors affecting the abundance of Ostreopsis cf ovata. Salinity variations exhibit a weak, insignificant influence on the abundance of specimens attached to Chlorophyta spp., and a negligible effect for those on Rhodophyta spp. (Table 3). The Ostreopsis maximum (Fig. 3) was found in summer (July) associated with the highest water temperature (28.4 oC), while its minimum was recorded in winter (February) at a much lower temperature (17.6 oC). Tempera- ture is a key factor determining the Ostreopsis blooms, but on site-specific bases, its dynamics and distribution in summer is driven by a combination of light intensity, wave activity, etc. Allelopathy has also been suggested among the biotic factors crucial to Ostreopsis occurrence [14]. Although O. cf ovata was found on all of the examined macroalgae, its abundance was ranked between Chlorophyta > Rhodophyta > Phaeophyta. The highest abundance was observed between spring and autumn with the peak on chlorophycean species in July, followed by a sharp decline in winter with the minimum in February (Table 3). The results showed relevant differences in the abundance of O. cf ovata depending on the macroalgal host species. The Chlorophytes Ulva linza, followed by U. fasciata and U. compressa seemed particularly suitable to support relatively high abundances of Ostreopsis during May and July; abundance was relatively less on U. lactuca in October. Our results suggest Chlorophytes might be an optimal macroalgal substrate for epiphytic Ostreopsis in the study area. Conversely, previous studies in the Mediterranean showed that the Ulvaceae constituted the substrate of least preference. Some factors, such as the sampling protocol and seasonality of the macroalgae, may explain these discrepancies. As for the Rhodophyta, the maximum abundance was found on Corallina (=Ellisolandia) officinalis in July and October. The occurrence of Phaeophyta species was restricted to May and July, and among them, Padina pavonia contained the highest abundances. In summary, Ostreopsis cf ovata may pose an additional threat to public health and the economy of Alexandria. Temperature, PO4 and NO3 seemed to be the main factors influencing its abundance. Ostreopsis cf. ovata had the ability to attach to diverse macroalgae species, with preference for Chlorophyta. Since O. cf. ovata cells are loosely attached to the substrata and can be easily removed and re-suspended in the water column, future studies about their relation with wave dynamics should be addressed. To our knowledge, this is the first ecological study of epiphytic forms of this species during a full annual cycle in the SE Continued on page 16 7 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 63 - December 2019 www.ioc-unesco.org/hab Harmful Algal Blooms in a Changing Climate In September 2019 the Intergovernmental Panel on Climate Change (IPCC) approved and accepted the Special Report on the Ocean and Cryosphere New Initiative on Fish-Killing Algal Blooms An Advanced International Colloquium and Technical Workshop on Fish-Killing HABs under the auspices of IOC-IPHAB and GlobalHAB, and with the support of the government of Chile through CORFO and collaboration of CREAN-IFOP, was held in Puerto Varas, Chile, IOC-SCOR GlobalHAB Workshop: Evaluating, Reducing and Mitigating the Cost of Harmful Algal Blooms: a Compendium of Case Studies Over the last two decades, several reports have compiled what is known about the economic impacts of harmful algal blooms (HABs) [1-4]. Although these reports attempted to Several examples of HAB-related losses and loss mitigation were discussed at the workshop in detail. A HAB incident in northern Norway alone resulted in the loss of 14 thousand tons of Atlantic salmon in May 2019, resulting in a total loss of at least 330 million USD, including insured losses of 45 Massive fish mortality in Teluk Bahang, Penang, Malaysia caused by a hypoxia-inducing algal bloom Fish kill events due to algal blooms have been increased dramatically over the past decades. Several massive fish kill events have been reported in Malaysia [1-5]. Among the incidents reported, some are Blooms of the potentially harmful raphidophyte Chattonella antiqua and the occurrence of the epiphytic dinoflagellate Ostreopsis cf. ovata in the coastal waters of Alexandria, Egypt coastal marine areas. Blooms of this genus are usually accompanied by goldenbrown seawater discoloration due to their Table 1. Seawater physical and chemical parameters during the summer 2019 Chattonella bloom mg O2/L Nutrient concentration μM C Salinit y pH DO COD PO4 SiO4 NO2 NO3 NH4 35.00 17.8 8.64 6.3 22.5 13.35 58 12.6 20.6 45.2 TN SiO4 PO4 Table 2. Physical and chemical properties of First records of Gambierdiscus excentricus and Ostreopsis lenticularis in the Cape Verde Archipelago (Macaronesia, Central Eastern Atlanctic) Fig. 1. Map of Cape Verde archipelago (Macaronesia Region). Harmful algal blooms (HAB) species frequently recorded in tropical latitudes are apparently incr Fig. 3. Gambierdiscus excentricus. Scanning electron micrographs, apical and ventral views mostly on the left side of the cell. The second apical plate (2) was narrow and elongated, and located below the APC, extending dorsally to the Po plate, and reaching about the mid-position of the 3 plate. Pl Microcystis bloom in Saladito river, central-southern Cuba Fig. 1. Map showing the cyanobacterial bloom area in Saladito River, central-southern Cuba. Water blooms or simply blooms in freshwater reservoirs are mass accumulations of planktonic microalgae or cyanobacteria. Water blooms (Wasserblüte) the center of the colony; a few solitary cells may appear in the mucilage. In our populations the typical solitary cells in mucilage were not observed, neither the concentrically lamellated margins. It is possible that the Cuban specimens could be identified as M. panniformis or M. novacekii, but fu Citizen Science Oceanography in the Strait of Georgia, Canada an overview of five years of operations The Citizen Science Oceanography Program for the coastal waters of British Columbia (BC), Canada was proposed by Dr. Eddy Carmack, Fisheries and Oceans Canada (DFO). Carmack envisioned a mosquito f harm (e.g. fish kills, shellfish poisoning) at very low concentrations. In the latter case, they are still called blooms because of their effects. These types of blooms can be invisible to the naked eye and only in-situ sampling can detect them. During five years of observations, the heaviest blooms Multicoloured algal blooms in the NW Adriatic during 2018 The northern Adriatic is characterized by shallow waters (mean depth about 35 m), a weak bathymetric gradient along the main axis and a high riverine input on the western side, affecting both the circulation regime and the trophic status. As Fig. 4. A bloom of an unidentified gymnodinioid caused a brown-greenish discoloration. Fig. 6. Ostreopsis cf. ovata bloom causing bleaching of macroalgal thalli. Fig. 5. Green colored waters from a mixed bloom of diatoms and Prorocentrum cordatum. Fig. 7. Field sample showing Takayama tasmanica a A bloom of Prorocentrum triestinum in the Hossegor Marine Lake (France) Phytoplankton communities in the Hossegor marine lake (Southern French Atlantic coast, Fig. 1) have been monthly monitored since 1997 to protect human health (REPHY network: monitoring of toxin producing species which may contam The ICES Annual Science Conference 2019 The International Council for the Exploration of the Sea (ICES) annual science conference took place in Gothenburg, Sweden, 9-12th Sept 2019 with 738 participants from 38 countries attending. The conference opened with a lively panel discussion around sustaina 11th Irish Shellfish Safety Workshop At the 11th Shellfish Safety Workshop held in the Radisson Blu Hotel Athlone, Ireland, Joe Silke, Director of Marine Environment and Food Safety Services at the Marine Institute said, Irelands Shellfish Safety Monitoring Programme ensures that shellfish placed on Fig. 2. Oyster Farm. Photo courtesy of Fionn OFearghail, Marine Institute Marine Institute The Marine Institute is the state agency responsible for marine research, technology development and innovation in Ireland. The Marine Institute provides government, public agencies and the maritime industry The 33rd annual meeting of the Australasian Society for Phycology and Aquatic Botany (ASPAB) The 33rd annual ASPAB meeting was held at NIWAs Greta Point site in Wellington, New Zealand on 11-13 November 2019. This year most presentations were on macroalgae although in the past microalgae and HABs ha Forthcoming events Call for abstracts - ICHA 2020 The Organizing Committee is pleased to announce the call for abstracts and pre-registration for the 19th International Conference on Harmful Algal Blooms to be held from the 11th to the 16th of October 2020 in La Paz, Baja California Sur, Mexico. La 12th International Conference on Modern and Fossil Dinoflagellates The Canarian HABs Observatory (OCH) hosts the 12th edition of the International Conference on Modern and Fossil Dinoflagellates (DINO12), to be held from 13th to 17th July 2020 at the Alfredo Kraus Auditorium in Las Canteras beach, L