Bacterial water quality along the Southwestern coast of Tobago - PowerPoint PPT Presentation

Bacterial water quality along the Southwestern coast of Tobago Tuesday 30 th October, 2018 Sheldon Ramoutar Research Officer (Microbiology) Institute of Marine Affairs

INTRODUCTION TO MICROBIOLOGY Study of organisms too small to be seen by naked eye. Bacteria Protozoa Fungi Virus

WHY STUDY MICROBIOLOGY Microbes are related to all life • Found everywhere • Most are beneficial Vital to plants and animals -food web, nutrient cycling, protection etc

Humans

ONLY A MINORITY ARE PATHOGENIC (1-10%) Sewage pollution- Effects Corals  Stimulate expulsion of good microbes  Decreased antibodies production  Weaken defence  More susceptible to diseases Seagrasses  Oxygen depletion  Development of anaerobic metabolism  Release sulphide and methane (toxic)  More susceptible to diseases

ONLY A MINORITY ARE PATHOGENIC (1-10%) Symptoms of waterborne diseases • Infections of : • respiratory tract, • ears, eyes, nasal cavity Skin • • gastrointestinal illnesses • severe diarrhoea • Nausea • headaches • fatigue

Indicator Organisms • Useful for all water types • Always present when pathogens are present • Not present in the absence of pathogens • Correlated with degree of pollution • More easily detectable than some pathogens Water use Indicator Organisms Drinking water Total Coliform Freshwater Faecal Coliform, E.coli Saltwater Total and Faecal, Enterococci Wastewater Faecal Coliform Reclaimed water Total Coliform (agriculture use)

METHOD- SAMPLING Coral and Seagrass Monitoring Recreational Station Site Location Ecosystem Programme Activity 1 Bon Accord Seagrass Watersports Nutrient parameters • Lagoon Nitrates, Ammonia, Phosphates • Bon Accord 2 Seagrass Watersports Suspended solids (TSS) • Lagoon Physico-chemical • Buccoo Bay 3 Seagrass Watersports Dissolved Oxygen (DO) • Kilgwyn Bay 4 Seagrass Bathing Temperature • La Guira Bay pH • 5 Seagrass Bathing Salinity • 6 Buccoo Reef Coral Reef Diving Rainfall data • Crown Point 9 Coral Reef Diving  Microbiology Pigeon Point Enterococci 10 Coral Reef, Bathing, Diving • beach Samples taken • Buccoo Reef 11 Coral Reef Diving Wet season • Buccoo Reef 12 Coral Reef Diving Dry season •

Method – Analysis (IDEXX) -Add reagent to water -Pour into package and seal -Incubate at specific temperatures -Count fluorescing wells under UV light -Use MPN Table -Compare to acceptable standard (USEPA, WHO)

Method – Analysis (Membrane Filtration) -Filter water through a 0.45 μm membrane filter -Place membrane on selective media -Incubate at specific temperatures -Count colonies -Compare to acceptable standard (USEPA, WHO)

RESULTS : PHYSICO-CHEMICAL DATA Sites pH Rainfall/mm DO Temperature Salinity USEPA 6.5 – 8.5 N/A >5 Not exceed 3°C above N/A 1995 ambient Limits Dry Wet Dry Wet Dry Wet Dry Wet Dry Wet 8.1  0.2 8.1  0.1 6  10.4 27.8  13.6 6.3  0.8 5.9  2.3 27.1  0.2 28.7  0.2 36.9  2.5 28.9  4.3 Bon Accord Lagoon 8.1  0.2 8.0  0.1 6  10.4 27.8  13.6 5.8  1.3 5.2  3.4 27.1  0.2 28.6  0.2 37.2  2.7 29.2  3.5 Bon Accord Lagoon 8.1  0.2 8.1  0.2 6  10.4 27.8  13.6 6.5  0.4 5.9  1.3 27.0  0.2 28.2  0.4 37.2  2.1 28.6  2.4 Buccoo Bay Kilgwyn 7.8  0.3 7.7  0.1 6  10.4 27.8  13.6 5.4  0.2 5.1  1.5 26.9  0.7 28.6  0.5 36.7  1.9 29.1  4.5 Bay La Guira 7.6  0.4 7.7  0.2 6  10.4 27.8  13.6 5.7  0.3 5.1  2.1 26.5  0.8 28.6  0.3 35.2  3.4 29.2  4.7 Bay 8.0  0.2 7.9  0.1 6  10.4 27.8  13.6 6.2  0.3 6.7  3.7 27.0  0.3 28.4  0.2 36.9  2.6 28.8  2.5 Buccoo Reef Crown 8.0  0.2 7.9  0.2 6  10.4 27.8  13.6 6.1  0.1 6.9  1.2 26.9  0.4 27.9  0.3 37.2  2.2 27.6  4.6 Point Pigeon 8.0  0.2 8.0  0.3 6  10.4 27.8  13.6 6.5  0.4 6.5  1.1 26.9  0.5 27.9  0.6 37.1  2.4 27.4  4.5 Point 7.9  0.2 7.8  0.2 6  10.4 27.8  13.6 5.7  0.9 6.6  2.3 26.9  0.5 28.4  0.3 37.0  2.5 29.2  2.2 Buccoo Reef 8.0  0.2 8.1  0.1 6  10.4 27.8  13.6 5.4  0.7 6.7  1.1 26.7  0.3 28.3  0.4 37.4  2.1 27.3  2.5 Buccoo Reef 8.1  0.2 8.1  0.1 6  10.4 27.8  13.6 6.1  0.1 6.9  1.8 27.0  0.5 28.1  0.3 37.4  2.0 30.2  6.5 Bon Accord Lagoon 8.1  0.2 8.2  0.2 6  10.4 27.8  13.6 6.2  0.3 6.7  1.4 27.0  0.5 28.3  0.4 37.4  1.9 31.1  4.6 Bon Accord Lagoon

RESULTS : MICROBIAL DATA Recreational Water Quality limit : 104 CFU /100 ml - Wet season had higher values - Four locations failed during the wet season

DISCUSSION – MITIGATION Limit Inputs of Bacteria into Watercourses • Fix malfunctioning wastewater treatment plants • Implement efficient sewerage systems • Limit land-based run-off from farms Public Awareness • Avoid poor water quality areas Rainy season ( rainfall events) • • Understand the risks involved to • Ecosystems and Humans

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