Mainly based on seafood consumption and its associated risks with respect to various toxins which includes fungal, algal and biological toxins.

1. -PRESENTED BY
Chayanika Das
Dept. of Fish Processing Technology
Regd. no: I-18-TN-02-003-M-F-031

2. SYNOPSIS
• INTRODUCTION
• FISH PRODUCTION (Global and Indian Scenario)
• NUTRITIONAL BENEFITS OF SEAFOOD
• GLOBAL SEAFOOD CONSUMPTION
• RISK AND HAZARD
• RISK ASSOCIATED WITH SEAFOOD
• TOXINS
• SEAFOOD BORN TOXINS
• FISH TOXINS
• CONCLUSION
• RECOMMENDATIONS
• REFERENCES

3. INTRODUCTION
• Seafood is any form of ‘sea life’ regarded as food
by humans prominently including fish and shellfish
along with crustaceans and edible seaweeds
• Seafood is an extremely diverse food commodity
representing most animal phyla, and is produced in
a wide spectrum of marine and freshwater
environments.
• Seafood production environments are potential
sources of almost every known foodborne hazard
including pathogens, parasites, marine toxins and
chemical contaminants (DePaola, 2014)

4. Cont…
• The biomass we consume as seafood starts
out as unicellular marine plankton,
transformed through one or more steps into
or fish or shellfish.
• Some species of plankton produce potent
natural toxins, accumulate in seafood and
can cause death or serious illness in human
consumers.
• To manage the problem, we need to
understand the nature of the toxins and the
organisms that produce them.

5. FISH PRODUCTION
• Fish is an important source of
protein
Economic activities
Harvest
Handling
Processing and distribution
Provides: Livelihood & Foreign
exchange earnings

6. GLOBAL DEMAND
World fish production (2018)- 178.8 MMT

7. INDIAN SCENARIO
Total fish production (2017-18)- 12.59 MMT
Marine production - 3.69 MMT
Inland production- 8.90 MMT
Revenue generated: 45,106.89 crores

8. Seafood – Nutritional Benefits
High Quality Protein
Rich in OMEGA-3 Fatty Acids

9. CONTRIBUTES TO A HEALTHY
HEART
Lowers triglyceride levels
Counteracts inflammation
Helps arteries stay elastic
Helps prevent build-up of plaque
deposits
Reduces risk of heart attack

10. • Low in saturated fats
• Contributes to proper growth
and development of children
• Source of vitamins and
minerals
Source of B complex vitamins
(Niacin, B12 and B6, thiamine)
Excellent source of minerals
(Calcium, iron, copper, potassium,
iodine, phosphorus, selenium,
magnesium)

11. CHOLESTEROL CONTENT OF SEAFOOD
• Most fish and shellfish contains
fewer than 100 milligram
cholesterol per 3-ounce of
cooked serving.
• Many leaner types of fish have
fewer than 50 milligrams per
serving.

12. GLOBAL SEAFOOD CONSUMPTION
As per FAO estimation per capita consumption is up to 20.5 kg
Asia has the highest per capita consumption of seafood

13. Many good reasons implied why people like to
consume seafood

14. Health benefits associated with fish consumption and
levels of supporting evidence

15. HAZARD
PHYSICAL
- Bolts and nut
- Metal fragments
- Sand particles
BIOLOGICAL
- Pathogenic
bacteria
- Virus
- Worms
- Helminths
CHEMICAL
- Marine toxins
- Heavy metals
- Pesticides
- Dyes
- Antibiotics
- Mycotoxins
RISK
A function the probability of an adverse health
effect and the severity of that effect, consequential
to a hazard in food
TWO PARTS
- The likelihood that a hazard will affect us
- The severity of its consequences if it does

16. Hazard identified in seafood (both wild and aquaculture)

17. RISK ASSOCIATED WITH SEAFOOD
Contaminants in seafood:
Heavy metal (Hg, Cd, Pb, Ar, Cu)
Biotoxins
Cadmium- Itai itai disease or ouch ouch
disease
Lethal dose: 3 ppm
Lead- Disease: Plumbism
Lethal dose:1.5 ppm

19. Cont..
Arsenic- Disease: Black foot disease (first recorded in Bangladesh)
Lethal dose: 75 ppm
Mercury: Toxic – Methyl mercury
Disease : Minamata (first recorded in Japan)
Lethal dose: 1 ppm
• 80 to 90% of organic mercury in human body is from fish and shellfish
intake
• 75 to 90% of organic mercury existing in fish and shellfish is methyl
mercury

20. Bioaccumulation of methyl mercury
• Bioaccumulation occurs when
organism contains higher
concentration of the substance
than the surrounding
• Bio magnification : larger
predator fish with high level of
mercury through ingestion of
smaller fish that have acquired
mercury through ingestion of
planktons

21. HEALTH EFFECTS OF METHYL MERCURY
• Reproductive effects: exposure to high concentration methyl mercury for a short
period included reduced number of sperms, testicular atrophy, reduced size of
infants in one birth, reduced survival rate of fetuses, and fetus deformity
• Neurotoxicity: refers to damage to the brain or peripheral nervous system caused by
exposure to natural or man-made toxic substances. Motor disturbances such as
ataxia and trembling, and dysesthesia such as impaired vision
• Carcinogenicity: mice fed with 10 mg/kg of methyl mercury, chronic kidney failure,
adenoma, and carcinoma were observed.
• Cardiovascular effects:death from coronary heart disease and incidence of acute
myocardial infarction became twice as high as hair mercury concentration increased
by 2 µg/g

23. TOXINS
TOXIN: a poisonous substance that is a specific product of the
metabolic activities of a living organism and is usually very unstable,
notably toxic when introduced into the tissues, and typically capable of
inducing antibody formation.
Classification (origin)
Algal toxins
 Bacterial toxins
 Mycotoxins (fungal toxins)
 Phytotoxins (plant toxins)

24. BACTERIAL TOXINS
• Most of the food born diseases are
reported due to the bacterial invasion
• In US cost due to food born diseases is
reported to be $8.4 billion
• Bacteria associated with food born
toxins includes
Bacillus cereus (diarrheal type)
Clostridium spp
Escherichia coli (enterohemorrhagic and
enterotoxigenic)
Vibrio spp
Salmonella
Shigella
Staphylococcus
Listeria

25. BACTERIA SYMPTOMS DISEASE CAUSED
Bacillus cereus Diarrhea, severe
emetic (vomiting)
reaction
toxicoinfection
Campylobacter jejuni Insignificant enteritis
to enterocolitis
human diarrhea
C. perfringens Nausea, abdominal
pain, and acute
diarrhea,
Gastroenteritis
Escherichia coli Bloody diarrhea and
severe abdominal
pain
Hemorrhagic colitis,
hemolytic uremic
syndrome, and
thrombotic
thrombocytopenic
purpura
Vibrio cholerae mild diarrhea, or may
have profuse, watery
diarrhea
Cholerae
• Clostridium botulinum :50% of foodborne
mortality (1899 and 1973).Toxin: C.
botulinum type E toxin
• Staphylococcus aureus: second most
commonly reported foodborne disease in
the U.S.Toxin: enterotoxin results in
staphyloenterotoxicosis,
staphyloenterotoxemia.

26. Cont…
• Shellfish are more likely to be a
source of infection than water:
Filter-feeders: thereby capable
of concentrating bacteria
• V. vulnificus is a dangerous vibrio
associated with marine
environments. Its primary
vehicles are raw or undercooked
seafood, particularly oysters and
clams

27. MYCOTOXINS
• According to FAO at least 25% of world’s
food crops are affected by mycotoxins
annually.
• Includes over 250 detected toxins
produced by at least 120 different micro-
or mould-fungi during favourable
condition.
• Mycotoxins originating from the species
of the genera includes -
Aflatoxin, Aspergillus, Fusarium,
Penicillium, Byssochlamis, Ochratoxins,
Sterigmatocystin, Zearalenone,
Fumonisins, Patulin, Trichothecenes,
Claviceps and many others.

28. AFLATOXIN
• It has been shown to be most potent hepatotoxins
and carcinogens in many species
• Three species: A. flavus, A. parasiticus, and A. nomius
• Formation of highest concentration of aflatoxins is
caused by the postharvest storage of foodstuffs in
unsuitable conditions
• Contamination of plant material with aflatoxin is also
reported, in wheat, corn, rice, soybeans, tree nuts etc
• Rat,poultry and rainbow trouts are highly susceptible
to the effects of aflatoxins.

30. • Ammonia heat treatments
• Chemicals resulting in acceptable detoxification includes:
Monomethylamine
Sodium hydroxide
Sodium hypochlorite
Hydrogen peroxide
• Thermal inactivation
• Irradiation
• Mechanical separation

31. PERMITED LEVELS PRESCRIBED BY USFDA COMMODITY
20 ppb of AFB1 Human foods and selected animal feeds
300 ppb Specific commodities and under selected animal
feeding operation
0.5 ppb of AFM1 Milk

32. SEAFOOD BORN TOXINS
• Few out of many toxin-containing organisms are related with food
toxicology
• Toxic compounds are produced either by:
- Edible organisms (fish, shellfish)
- Plankton or algae : ingested by fish or shellfish: phycotoxins.
• Organisms responsible: clams, lobsters, mussels, oysters, scallops
• Shellfish poisonings are divided into four groups- paralytic,
diarrhectic, neurotoxic and amnesic
• Finfish poisoning: Scombroid or histamine, puffer fish and ciguatera
poisoning

34. RISK ASSESSMENT OF SEAFOOD

35. PARALYTIC SHELLFISH POISONING
Death of Humpback
whale due to
saxitoxin in
mackerel it had
consumed.
Produced by sea dinoflagellates (Alexandium
tamarense, A. catenella, Gymnodinium catenatum
etc) and cyanobacterium (Aphanizomenon flos-
aquae)
Symptoms includes: numbness of lips, tongue,
fingertips progressing eventually leading to
breath paralysis and death
Toxin responsible – Saxitoxin, dissolves well in
water, highly stable in acidic and neutral pH. Death
occurrence by respiratory arrest
Lethal dose: 4 mg of saxitoxin considered fatal
Action level for Saxitoxin: 80μg/100 g tissue

36. Origin of the name saxitoxin:
Saxidomus giganteus (Mollusk)
Freshwater: Anabaena circinalis
(Blue algae)
Human Nervous system
supersensitive to this toxin
ACTION: reversibly block the inflow of
Na+ ions into the nerve cell via Na-
channels
CAUSE DEATH BY RESPIRATORY
ARREST
DETECTICTION METHODS
- Mouse bioassay
- HPLC Technology
- ELISA
- EIA (Enzyme Immunoassey)

37. Diarrhectic shellfish poisoning
Produced by dinoflagellates of genus
Dinophysis (D. fortii, D. acuminate and
others) and maybe Prorocentrum
Toxin responsible divided in three
groups
- Okadoic acid and its derivative
dinophysistoxins
- Pectenotoxins
- Yessotoxins
Symptoms of poisoning are nausea,
vomiting, diarrhea and abdominal pain
Maximum allowable content by EU is
0.16 μg/g
DSP is not life threatening

38. • First DSP was diagnosed in
Japan, in the province of
Tohoku
• The toxin responsible
Ocadoic acid first isolated
from the sponge
Halichrondia okadai
• Range: Japan, Southeast Asia,
Chile, New Zealand, Western
Europe, Eastern Canada,
Scandinavia
DETECTION METHODS
- Mouse bioassay
- LC-MS/MS
- ELISA
MECHANISM OF ACTION
- Inhibits protein phosphate 1 and 2A which
controls Na+ secretion from intestinal cells
- Loss of fluids and ions from gut epithelial cells
- Leading to gastrointestinal illness
- Recovery: Within 3 days

39. Neurotoxic shellfish poisoning
Produced mainly by dinoflagellate Ptychodiscus brevis
Toxic to fishes but not to shellfish
Toxin responsible: Brevetoxin
Symptoms : paresthesias of the lips, tongue, and throat,
reversal of hot and cold sensations, fever, dizziness, and
broadening of pupils.
Lethal limit to be considered <80μg/100 g
Recovery takes place within 24 hours

40. MODE OF ACTION:
• Brevetoxins are polycyclic ethers
that bind to and stimulate Na+
flux through voltage-gated Na+
channels in nerve and muscle.
• These toxins are depolarizing
substances that open voltage-
gated Na+ ion channels in cell
walls, leading to uncontrolled
Na+ influx into the cell.
• This alters the membrane
properties of excitable cell types
in ways that enhance the inward
flow of Na+ ions into the cell.
DETECTION METHODS
Brevetoxin can be assayed by using
• Mouse bioassay
• ELISA
• antibody radioimmunoassay.
Chemical structure of Brevetoxin

41. Produced from the domoic
algae of genus
Pseufonitzschia such as P.
pungens, P. multiseries, P.
australis, P. turgiduala.
Toxin responsible is domoic
acid
Soluble in water and poorly
soluble in organic solvents.
Permissible limit of domoic acid
in mollusks is 20 mg/kg

43. FISH TOXINS

45. Aquatic Food web showing origin of toxins from
Harmful Algae and distribution through ecosystem
Marine biotoxins- algal
metabolites that can
accumulate in fish or
shellfish and render these
foodstuffs improper for
human consumption
(Zendong et al.,2014).

46. TETRODOTOXIN
Source: puffer fish or
fugu (Takifugu niphobles)
Toxin: Tetrodotoxin
• Human lethal dose of TTX is about 10μg/kg bw, that is 1mg
per adult
• Symptoms: slight numbness of the lips and tongue appears
with paresthesia in the mouth, dizziness, tiredness, headache,
pressure sensation in the throat and breast, nausea partial
muscular paralysis and collapse
• Occurance of death- 4-6 hours or even 20 min.

47. 75% women migrants from Tamil Nadu engaged in puffer fish processing in Karnataka (Mangalore and Malpe Harbour)
20% - local- dry fish making (Karnataka)
80% - Tamil Nadu- Marketed to Malaysia and China

48. CIGUATOXIN
OCCURANCE
Gambiertoxins produced by
Gambierdisccus toxicus and related
dinoflagellates inhabit on microalgae
adhered to dead corals.
When consumed by herbivores
gambiertoxin converts into ciguatoxin in
its muscles and gets transferred into the
foodchain.
LETHAL LIMITS
- Can cause human
intoxication at its
concentration of 0.1
μg/kg of fish meat
- Caribbean
ciguatoxin: 1.0
μg/kg

49. POISONING FROM CIGUATOXIN AND
OTHER SHELLFISH TOXINS :
- According to statistics from the centre for Health
Protection, 365 cases of ciguatoxin poisoning
affecting 1,356 people
- 69 cases of shellfish poisoning affecting 145 people
were reported in Hong Kong from 1997 to 2006
FACTS ON CIGUATOXIN:
- Most frequently reported seafood related disease
- Cannot be detected by appearance, taste, or smell and
the toxin cannot be removed by freezing, filleting or
cooking the fish
- The larger the fish the greater the potential for poisoning
- Can be treated with a drug called Mannitol if diagnosed
within 24 hours

50. SCOMBROID POISONING/ HISTAMINE
POISONING
FORMATION OF HISTAMINE
During spoilage and improper
storage by conversion of the free
amino acid histidine in muscles of
dead fish with the presence of
certain bacteria.
SOURCE
Scombroid and non
scombroid fish species
including: Herring, pink
salmon, redfish
yellowtail, marlin,
sailfish, amberjack,
mahi-mahi, Tuna,
mackerel, sardines,
anchovies, bonito, etc
CAUSATIVE AGENT
Histamine along
with the presence
of putrescine and
cadaverine which
enhance the toxicity
LEGAL LIMITS OF HISTAMINE:
- EU regulation maximum permitted
histamine concentration in fresh fish
products of the Scombridae and
Clupeidae families is 100mg/kg and in
cured products of the same species is up
to 400 mg/kg.
- FDA regulation: 50 mg/kg as potential
health hazard.
- In Australia, the legal limit of
histamine concentration is 200 mg/kg
and in South Africa, the limit is 100
mg/kg.
CLINICAL SYMPTOMS
Occurance of facial flushuing, rashes, and palpitations, headaches,
edema, and a burning or peppery taste in the mouth typical of
allergic reactions, diarrhea and abdominal cramps.
More severe symptoms such as: Respiratory distress, swelling of
the tongue and throat, and blurred vision can occur and require
medical treatment with antihistamines.

52. RECENT CASES OF SEAFOOD TOXINS FOUND IN INDIAN COAST
• Highest concentration of PST :
Oyster (Mulki & Sasthana)
followed by Mussel (Gangoli &
Someshwar)
• No evidence of TTX (samples
not collected from intertidal
zone)
• AST: Not detected (little
evidence of this toxin from this
area)

53. CONCLUSION
• Consumption of variety of seafood causes an increasing number of human intoxications &
majorly is due to lack of information on harmful algal biology
• Monitoring seafood for toxicity is essential to manage the risks especially the toxic plankton
• Diagnosis depends mainly on recognition of specific signs-symptoms and on identification
of marine toxins, however several limitation occurs such as variation in toxin content,
different detection and extraction methods, frequency of sampling

54. The development and introduction of adequate and efficient analytical
methods
Chemical analytical techniques capable of separating , identifying and
quantifying individual marine toxins should be further developed
A database should be developed including basic data on marine
biotoxins

55. REFERENCES
• Anonymous 2000a. Handbook of Fisheries Statistics, Department of Animal Husbandry and
Dairying, Ministry of Agriculture, Government of India, New Delhi.
• Baki, M.A., Hossain, M.M., Akter, J., Quraishi, S.B., Shojib, M.F.H., Ullah, A.A. and Khan, M.F.,
2018. Concentration of heavy metals in seafood (fishes, shrimp, lobster and crabs) and human
health assessment in Saint Martin Island, Bangladesh. Ecotoxicology and environmental
safety, 159, pp.153-163.
• Canton, J.H., Kroes, R., Van Logten, M.J., Van Schothorst, M., Stavenuiter, J.F.C. and
Verhülsdonk, C.A.H., 1975. The carcinogenicity of aflatoxin M1in rainbow trout. Food and
cosmetics toxicology, 13(4), pp.441-443.
• Dashwood, R., Negishi, T., Hayatsu, H., Breinholt, V., Hendricks, J. and Bailey, G., 1998.
Chemopreventive properties of chlorophylls towards aflatoxin B1: a review of the
antimutagenicity and anticarcinogenicity data in rainbow trout. Mutation
Research/Fundamental and Molecular Mechanisms of Mutagenesis, 399(2), pp.245-253.

56. Cont…
• DePaola, A. and Toyofuku, H., 2014. Safety of food and beverages:
seafood.
• Hong, Y.S., Kim, Y.M. and Lee, K.E., 2012. Methylmercury exposure and
health effects. Journal of Preventive Medicine and Public Health, 45(6),
p.353
• Omaye, S.T., 2004. Food and nutritional toxicology. CRC Press.
• Todd, E.C., 1993. Domoic acid and amnesic shellfish poisoning-a
review. Journal of food protection, 56(1), pp.69-83.