BACTERIAL CONTAMINATION AND HEAVY METAL RESIDUES IN FROZEN SHELLFISH RETAILED WITHIN LAGOS METROPOLIS, NIGERIA

  • O.A. Afolayan Department of Fisheries Technology, Federal College of Fisheries and Marine Technology, V.I, Lagos
  • R.O. Moruf Department of Fisheries and Aquaculture, Bayero University, Kano
  • A.O. Lawal-Are Department of Marine Sciences, University of Lagos, Akoka, Lagos

Abstract

Shellfish has become a worldwide delicacy amongst seafood lovers due to its essential nutrients which are beneficial to human health. An investigative study was carried out on eight different shellfish– White Shrimp (Penaeus occidentalis), Tiger Shrimp (Penaeus monodon), Pink Shrimp (Farfantepenaeus notialis), Guinean Mantis Shrimp (Squilla aculeata calmani), Royal Spiny Lobster (Pallinurius regius), Lagoon Crab (Callinectes amnicola), Smoothswim Crab (Portunus validus) and Periwinkle (Tympanotonus fuscatus) obtained from Better Life market- exploring their bacterial quality and heavy metal accumulation. The highest Total Bacterial Count (2.71±0.03×108 CFU/g) was observed in P. occidentalis while the lowest count (1.00±0.04×108 cfu/g) was observed in T. fuscatus. The Total Faecal Count of the shellfishes reduced under 440C temperatures except in P. occidentalis which increased from 1.40±0.05×103 to 1.70±0.01×103 CFU/g.  Although, all identified bacteria (Bacillus spp, Escherichia coli, Lactobacillus spp, Pseudomonas aeruginosa and Klebsiella spp ) were found in C. amnicola  and T. fuscatus but the most contaminated  shellfish was Penaeus occidentalis, with 38.5% E. coli, followed by F. notialis having 37.3% P. aeruginosa. The mean heavy metals concentration occurred in the following decreasing order: Iron> Zinc> Copper> Chromium> Manganese while Cadmium, Lead, Nickel and Arsenic were not detected in most of the samples. The study revealed that frozen shellfish are preserved under unhygienic environment most times and the fact that some levels of toxic metals were found in the samples is a cause for constant monitoring.

Published
2020-03-29
Section
ARTICLES