Regional Workshop on Monitoring and Management Strategies for Benthic HABs

Status of toxicity project in Mauritius

Nushreen Jeenally

Albion Research Centre Mauritius

Musée océanographique - Monaco, 9th to 12th April Country profile Land Area 1,864 Sq. Km The EEZ of Mauritius has a Capital Port Louis reasonable stock of various fish, including pelagic and demersal Population 1.26 million . Fisheries resources GDP per Capita USD 9,904.6 (2017 exploited include the island- estimate) based artisanal fisheries ( Seafood industry 1.5% of national and offlagoon), Fish Aggregating GDP Devices (FADs) (off- Exclusive 2.3 million Km² Economic Zone (including approx. lagoon), the offshore demersal 400,000 Km² jointly fishery of the banks of the managed with the Mascarene Plateau and the Seychelles) Chagos Archipelago, and the Coastline of 250 km Mauritius fishery in the Western Coral reef 150 km Indian (industrial fisheries). Currency Mauritian Rupees 1 USD = MUR 36

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Ministry of Ocean Economy, Marine Resources, Fisheries and Shipping

VISION To be an economic pillar with due regard to sustainability of aquatic resources and social development for the benefit of all stakeholders.

MISSION

To provide an enabling environment for the promotion of sustainable development of the fisheries sector and to ensure continued economic growth and social development within the framework of good governance.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April

Albion Fisheries Research Center (AFRC)

The AFRC carries out the research, development and management functions of the Ministry of Ocean Economy, Marine Resources, Fisheries and Shipping - constructed and equipped with Japanese assistance in three phases between 1981 to 1995.

Projects are implemented through 5 divisions namely: Aquaculture, Marine Science, Marine Conservation, Marine Resources and Laboratories.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April AFRC Laboratories

The Laboratories Division at the Albion Fisheries Research Centre (AFRC) comprises the Fish Toxicity, Marine Chemistry and Marine Microbiology laboratories. The marine chemistry and marine microbiology laboratories have been accredited to MS ISO/IEC 17025:2005 standard by the Mauritius Accreditation Service (MAURITAS).

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Fish Toxicity Laboratory

1. Monitoring of Harmful Marine Microalgae

2. Testing of toxic for ciguatoxins Grand Baie Trou aux Biches

Albion

Blue Le Morne

Sites around Mauritius for HAB monitoring

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Identification and enumeration of Harmful Marine Microalgae

11 species of benthic belonging to genera Gambierdiscus, Prorocentrum, Ostreopsis, Coolia and Amphidinum were observed in the lagoon of Mauritius.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Harmful marine Microalgae monitoring 2015 - 2017 14000

High level of 12000

Ostreopsis Sp and prorocentrum sp. 10000 throughout the past years.

8000 Macroalgae: Padina 6000 gymnospora., Sargassum sp., 4000 Ulva sp., Halymenia Number ofcell per 100g ofmacro algae durvillaei, 2000 Turbinaria sp.

0 Albion Le Grand Blue Bay Trou Aux Albion Le Grand Blue Bay Trou Aux Albion Le Grand Blue BayTrou Aux Morne Bay Biches Morne Bay Biches Morne Bay Biches 2015 2016 2017 Sites monitored / Years

Amphidinum sp. Coolia sp. Gambierdiscus sp. Ostreopsis sp. Prorocentrum sp. Synophysis sp.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Fish Toxicity Project

Ongoing project at the AFRC since 1991.

Mongoose Bioassay :- • Mongooses trapped in the wild are acclimated to laboratory conditions and are fed on a normal diet. • After acclimation period of 10 days to 2 weeks, mongooses are fed on suspected fish specimens for 3 days. • are observed for any signs of intoxication which vary depending on the severity of the intoxication.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Symptoms and toxicity score in mongoose bioassay

Toxicity Score Description of visible symptoms 0 (Non Toxic) No symptoms after 3 days 1 (Mildly toxic) Slight weakness and flexion of fore limbs 2 (Mildly toxic) Slight motor ataxia 3 (Moderately toxic) Moderate motor ataxia and partial paralysis of limbs 4 (Highly toxic) Acute ataxia with limited movement 5 (Very toxic) Death

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Mouse Bioassay • Mongoose bioassay was replaced by mouse bioassay in1996.

• Ciguatoxin is extracted from 100g tissue sample with acetone, followed by diethyl ether and finally with hexane and assayed by intraperitoneal injection into 2 (20 ± 2g) test mice.

• Control mice would receive tween-60/1% sterile.

• Weight, time of injection, quantity of extract injected, signs of intoxication and time of death are recorded.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Mouse toxicity (symptoms) assay scoring

Toxicity Score Description of visible symptoms 0 (Non Toxic) No ill effect 1 (Very low toxicity) 15-60 min; muscle contraction in lower back area (flexion), increased respiration, immobile (inactive), recovery. 2 (Mildly toxic) Muscle contraction in lower back area, piloerection, recovery after 2-3 hours. 3 (Moderately toxic) Muscle contraction in lower back area, paralysis in extremities, rapid and irregular breathing, immobile, close eyes, piloerection, recovery 12-24 hours 4 (Highly toxic) Muscle contraction in lower back area, paralysis in extremities, rapid and irregular breathing, immobile, close eyes, piloerection, death within 24hours

5 (Very toxic) Muscle contraction in lower back area, paralysis in extremities, rapid and irregular breathing, immobile, close eyes, piloerection, death within 6hours

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Name of fish 2014 2015 2016 2017 Lutjanus sebae (Bourgeois) 12 2 0 0 Species of fish (1 not toxic) tested for Lutjanus bohar (vara vara) 1 6 0 0 (1 not toxic) toxicity Plectropomus sp. Headless and 5 0 0 0 gutted

unidentified (sliced, frozen/cooked) 3 4 2 5 (1 sample not toxic) Plectropomus laevis 6 0 0 0

Variola Louti (Croissant Queue Jaune) 9 5 1 0

Plectropomus punctatus (Merou 5 2 0 0 Pointille)

Aethaloperra rogaa 2 0 0 0 (Not toxic) Carangoides fuluoguttatus 0 1 0 Lutjanus gibbus 0 0 1 0 Sphyraena barracuda 0 0 2 0 Filleted of dried fish, sample 0 0 5 2 unidentifiable TOTAL 43 20 11 7

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Types Seafood poisoning in Mauritius

Other types of seafood poisoning which are most likely encountered in Mauritius (Halstead and Cox, 1973):

• Clupeoid fish poisoning (Harengula ovalis - patchy distribution , rare occasions) • Scombroid fish poisoning (tuna, tuna-like species) • Pufferfish poisoning (tetrodotoxins in ovary, skin, liver, intestine of porcupine fish and pufferfish) • Hallucinogenic fish poisoning (Siganus sp.) • Crab carpillus maculatus, the echinoderm Echinotrix sp., turtle eretmochelys imbricata.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Types of seafood Symptoms poisoning Clupeoid fish poisoning Nausea, vomiting, diarrhoea, abdominal pain, nervousness, numbness, tingling, muscular cramps, respiratory distress. Scombroid fish poisoning Nausea, vomiting, diarrhoea, abdominal pain, skin allergy (intense itching), headache, dizziness, cardiac palpitation, burning of throat, respiratory distress. Puffer fish poisoning Extreme weakness, skin disorders, muscular paralysis, respiratory distress, loss of motor coordination, hyper salivation, tingling, numbness. Hallucinogenic fish Muscular weakness, dizziness, loss of equilibrium, poisoning constriction of chest, burning of throat, nightmares.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Incidences of fish toxicity in Mauritius

Year Cases 1601 As sailors of the fleet led by Dutch Admiral Harmansen took ill after consuming fish caught off Le Morne (Poison Cape) (Halstead and Cox, 1973) 1967 Crab poisoning – Carpillus maculatus – fatal case in Mahebourg

1748 Worst outbreaks of ciguatera recoded took place near Rodrigues (1500 fatal cases due to consumption of serranidae) Between April 2 incidences of ciguatera: 1999 and March (a) Unidentified serranid caught in lagoon of Mauritius (6-7 people) 2000 (b) Variola Louti from Rodrigues (8 people – 1 death, other showed acute symptoms of ciguatera)

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Epidemiology

• 1985-2000: 1814 of fish poisoning of various types including ciguatera have been treated as in-patients in government hospitals.

• Average number of cases of fish toxicity reported between the period 1985 and 1995 was 139 per year.

• Drastic decrease to 57 cases per year from January 1996 to December 2000 - Incident rates 1.26/10000 and 0.52/10000 population

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April New cases of food poisoning reported to sanitary Authorities Cases of Food Poisoning in Rodrigues

2017 (mainly fish poisoning) 45

2016 2015 40 2014 35 2013 30 2012

reported reported cases 25 2011 20 2010 15 year 2009

2008 Numberof 10 2007 5 2006 0 2014 2015 2016 2005 Year 2004 2003 2002 2001 Symptoms reported: 0 100 200 300 400 500 600 700 800 900 Number of cases of food poisoning Numbness, diarrhoea, Itching, rashes

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Legislation

The Fisheries and Marine Resources Act 2007—Fisheries and Marine Resources (Toxic Fish) Regulations 2004—defines, regulates and the sale of twenty one species/groups of fishes and other marine organisms in Mauritius.

Regulations in 1886 ban sale of certain species of fish due to fish

poisoning outbreaks.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Sensitisation Deliver talks to community centres, woman centres, schools, colleges, hotels. Lectures on fish poisoning to fishermen. Open days / exhibitions. Distribution of pamphlets, posters.

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW Musée océanographique - Monaco, 9th to 12th April Thank You

Regional Workshop on Monitoring and Management Strategies for Benthic HABs/ MOW YOUR Musée océanographique - Monaco, 9th to 12th April LOGO