Management of recreational waters in relationship with harmful microalgae blooms (HAB) in the Mediterranean Sea

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1 EVK WORKSHOP Management of recreational waters in relationship with harmful microalgae blooms (HAB) in the Mediterranean Sea 25 26th October 2004 Hotel Don Antonio, Peguera- Calvià, Mallorca

2 MONITORING OF HARMFUL MICROALGAE IN TUNISIA Dr Souad Turki Planktologist INSTM/Centre La Goulette Port de pêche, 2060 La Goulette. Tunisia Taxonomy and bio-ecoloy of zooplankton species in Tunisian waters within the framework of the management and aquaculture INSTM programs. Taxonomy and monitoring of harmful microalgae in Tunisian waters within the convention with Direction Générale des Services Vétérinaires (Ministère de l Agriculture)

3 Monitoring program on harmful microalgae Goals: Control health risks through the detection of toxic phytoplankton species in shellfish production areas and a contamination of shellfish by phycotoxins. Acquisition of information on Tunisian marine waters harmful algae blooms (red tide blooms)

4 ALGERIA Bizerte T U N I S I A Gabès Tunis Sfax Mediterranean Sea GULF OF TUNIS Sousse Sea of Boughrara Occurrence of harmful algae blooms in Tunisian waters LIBYA

5 Red tide blooms occurred in Tunisian waters and causative species ZONE DATE CAUSATIVE SPECIES Sea of Boughrara 1991 Gymnodinium cf maguelonnense (Dinophyceae) Gulf of Gabès Trichodesmium erythreum (Cyanophyceae) Gymnodinium cf maguelonnense (Dinophyceae) North Lake of Tunis 2000 Rhodomonas sp (Cryptophyceae) South Lake of Tunis 1994 Tetraselmis sp (Prasinophyceae) Lake of Ghar El Melh Prorocentrum micans (Dinophyceae) Gonyaulax polyedra (Dinophyceae) Prorocentrum minimum (Dinophyceae) Lake of Bizerte Gulf of Tunis 1999 Protoperidinium quinquecorne (Dinophyceae) 2003 Noctiluca scintillans (Dinophyceae)

6 Monitoring program of harmful microalgae species in Northern Tunisian waters: Sampling stations Bizerte Ariana Tunis Sampling sites in shellfish production areas, shellfish farms and urchin production areas in North of Tunisia. Principal regions:tunis, Bizerte and Ariana localities. 19 sampling stations

7 North lake of Tunis and chanel of Tunis Ecluses Tunis Chekli T1c Digue de séparation North lake of Tunis T2 T1s T1k Go lfe de Tunis Lake of Bizerte Bizerte Bizerte Mer Canal de navigation T2r 1 km Menzel Jémil T1s,T1c, T1k,T2 and T2r: Sampling stations Faroua B2 B1C B1B B1A Oued Tindj a Coasts of Bizerte 1 km B1A, B1B, B1C and B2 : Sampling stations Bivalvae farms

8 Potentially Toxic microalgae reported from northern Tunisian waters DSP PSP ASP Other toxins Dinophysis sacculus Dinophysis acumunata Dinophysis caudata Dinophysis rotundata Dinophysis fortii Prorocentrum lima Alexandrium minutum Alexandrium tamarense Alexandrium catenella Pseudonitzschia sp Prorocentrum concavum Prorocentrum mexicanum Prorocentrum minimum Ostreopsis siamensis Coolia monotis Gymnodinium cf galatheanum

9 Monitoring of DSP toxin producer species in Tunis production shellfish area: Dinophysis spp and Prorocentrum lima Tunis North lake of Tunis T2 T1 Gulf of Tunis Canal of Tunis T1 S O N D J F M A M J J A T2 S O N D J F M A M J J A Dinophysis spp > 500 cells/l Prorocentrum lima > 100 cells/l Bioassay test DSP >

10 Monitoring of DSP producer toxin species in the lake of Bizerte: Dinophysis spp and Prorocentrum lima B1 S O N D J F M A M J J A B2 B1 a A B2 S O N D J F M A M J J A Dinophysis spp >500 cells/l Prorocentrum lima > 100 cells/l Bioassay test DSP >

11 Duration time of the contamination clams by DSP toxins ( ) in Northern shellfish production areas Year Shellfish production area Duration time of biotoxins Date T1 T2 B1 & B2 1-2 weeks 1 week 1 week February-March October-Mars October-January-June T1 T2 B1 B2 1-4 weeks 1-2 weeks 4 weeks 1-3 weeks Sep.-Nov.-Dec.-Jan.-March-May December- February-March September September-October-November B1 B2 1-2 weeks 1 week October- February-May February-March

12 Alexandrium species recorded in Tunisian waters A. minutum* A. insuetum A. margalefi A. tamarense* A. pseudogonyaulax A. leei A. foedum A. kutnerae A. concavum A. catenella* * 3 species were Toxic These microalgae were recorded particularly in the lagoons and rarely in the gulf of Tunis where the concentrations were very low. Since 1996, no PSP events were recorded in shellfish production area of the Tunisian waters.

13 Monitoring of Alexandrium spp in shellfish production areas Northern Tunisia (September September 2004) A2 A1 B2 B1c FMB T6 B1b B1a T2r T2 T1k T1c T1s S1 S2 S3 S4 O1 O2 O3 O4 N1 N2 N3 N4 D1 D2 D3 D4 J1 J2 J3 J4 F1 F2 F3 F4 M1 M2 M3 M4 A1A2 A3 A4 M1 M2 M3 M4 J1 J2 J3 J3 J1 J2 J3 J4 A1 A2 A3 A4 0 cell/l 100 cells/l< Alexandrium ssp < 500 cells/l Alexandrium ssp > 500 cells/l From September 2003 to Septembre 2004, we have been noticed that the monitoring was about: * the presence of A. margalefi, A. pseudogonyaulx et A. leei have been detected particularly in the lake of Bizerte. * [A. pseudogonyaulax] reached the maximun density with 8750 cells/l. * Seasonal successions of these Alexandrium species: i- From March to April : apparition of A. margalefi [ cells/l], ii- From April to June, apparition of A. pseudogonyaulax [ cells/l] and / A. leei [250 cells/l] since September.

14 Conclusion Toxic phytoplankton species were reported mainly to Dinophysis spp (D. sacculus) and Prorocentrum lima, DSP producer toxins in Northern Tunisian shellfish production areas. No PSP events were recorded so far in shellfish production areas 11 species of Alexandrium were identified in Tunisian waters, these species were recorded particularly in the lake of Bizerte 3 species were known to be toxic: A. minutum, A. catenella and A. tamarense Abundance of these species was very low

15 Perspectives To develop a strategy of the monitoring of the Alexandrium microalgae The focus of this environmental program will be : * prevent blooms of these microalgae in recreational waters in South Mediterranean Sea (for example: the gulf of Tunis) by emphasis: - Taxonomy of these species and their detection even at low concentrations - Sampling and germination of the cysts - Culture techniques of the Alexandrium microalgae

16 Future activities Implementation of the monitoring harmful algal blooms program caused by Noctiluca scintillans in the gulf of Tunis: population ecology, origin, biology, reproduction, nutritional status. Data base on harmful microalgae from northern Tunisian waters