Assessment of Heavy Metal Pollution in
            <i>Octopus cyanea</i>
            in the Coastal Waters of Tanzania

Mshana, Johnson Grayson; Sekadende, Baraka C.

doi:10.5696/2156-9614-4-6.10

Cited by 10 publications

(5 citation statements)

References 19 publications

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“…Since aquatic animals can regulate and detoxify accumulated metals, the reported high levels of trace metals in octopus (Mshana andSekadende 2014), gastropods (De Wolf et al 2001), bivalves (Rumisha et al 2012), polychaetes (Mtanga and Machiwa 2007) and mudskippers (Kruitwagen et al 2008) from the Tanzanian coast show that these animals were continuously exposed to high levels of contaminants. Although tolerance varies among species, toxic effects occur when the accumulated metals exceed the threshold concentration that can be tolerated.…”

Section: Introductionmentioning

confidence: 99%

Bioaccumulation and public health implications of trace metals in edible tissues of the crustaceans Scylla serrata and Penaeus monodon from the Tanzanian coast

Rumisha

Leermakers

Mdegela

et al. 2017

Environ Monit Assess

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The coastal population in East Africa is growing rapidly but sewage treatment and recycling facilities in major cities and towns are poorly developed. Since estuarine mangroves are the main hotspots for pollutants, there is a potential for contaminants to accumulate in edible fauna and threaten public health. This study analysed trace metals in muscle tissues of the giant mud crabs (Scylla serrata) and the giant tiger prawns (Penaeus monodon) from the Tanzanian coast, in order to determine the extent of bioaccumulation and public health risks. A total of 180 samples of muscle tissues of S. serrata and 80 of P. monodon were collected from nine sites along the coast. Both species showed high levels of trace metals in the wet season and significant bioaccumulation of As, Cu and Zn. Due to their burrowing and feeding habits, mud crabs were more contaminated compared to tiger prawns sampled from the same sites. Apart from that, the measured levels of Cd, Cr and Pb did not exceed maximum limits for human consumption. Based on the current trend of fish consumption in Tanzania (7.7 kg/person/year), the measured elements (As, Cd, Co, Cu, Mn, Pb and Zn) are not likely to present health risks to shellfish consumers. Nevertheless, potential risks of As and Cu cannot be ruled out if the average per capita consumption is exceeded. This calls for strengthened waste management systems and pollution control measures.

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Section: Introductionmentioning

confidence: 99%

Bioaccumulation and public health implications of trace metals in edible tissues of the crustaceans Scylla serrata and Penaeus monodon from the Tanzanian coast

Rumisha

Leermakers

Mdegela

et al. 2017

Environ Monit Assess

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“…The climate is tropical, with hot weather throughout the year temperatures ranging from 26 to 35 °C and there are two rainy seasons: long rains in March-May and short rains in November-December. The industries in these areas manufacture a variety of goods for the local and foreign markets, and they include: distilleries, breweries, manufacturers of cigarettes, cement, paints, pharmaceuticals, plastic, metal products, steel, chemicals, confectionery, food products, timber and wood products, petroleum products, dairy products, batteries, printing, publishing and paper products, among others (Mshana and Sekadende 2014). Pollutants released from the aforementioned activities can find their ways into the coastal waters and affect the quality of seafood and health of their consumers.…”

Section: Description Of Study Sitementioning

confidence: 99%

Levels of selected toxic and essential elements in fish and oysters from Western Indian Ocean, Coast of Tanzania

Shilla

Sawe²

2021

Tanz. J. Sci.

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Concentrations of toxic and essential elements in selected finfish and shellfish collected from Dar es Salaam and Tanga, Indian Ocean coast of Tanzania are presented. The elemental concentrations were determined using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer coupled with X-lab ProTM software. The mean concentrations of metals observed in finfish and shellfish collected from Tanga ranged from 3.40–5.75, 1.8–37.17, 3.5–7.1, 0.6–1.3, 0.53–0.73 and 16.80–96.70 mg kg–1 for As, Cu, Mn, Ni, Pb and Zn, respectively. For Dar es Salaam, the mean concentrations of metals ranged from 3.34–9.46, 2.90–30.53, 3.4–6.9, 0.7–1.0, 0.57–0.80 and 14.2–100.90 mg kg–1 for As, Cu, Mn, Ni, Pb and Zn, respectively. Thumbprint emperor showed the highest levels of Cu and Ni; octopus showed the highest values of As and Pb, while sardines showed the highest level of Mn. Oysters, used as pollution indicators in this study showed the highest elemental concentrations and exceeded their mean levels in finfish from Dar es Salaam by factors of 1.30, 7.15, 6.27, 2.72, 1.29 and 35.57 for As, Cu, Mn, Ni, Pb and Zn, respectively. In samples from Tanga, the metal concentrations in oysters were several times higher (3.76, 17.68, 1.12, 3.89, 1.88 and 66.92 for As, Cu, Mn, Ni, Pb and Zn) than in finfish, respectively. Based on metal concentrations in oysters, it can be concluded that coastal waters are contaminated with heavy metals. However, with an exception of arsenic and copper, the elemental levels in finfish are within the maximum permissible levels recommended by various international standards and guidelines. Keywords: Finfish, toxic elements, essential elements, pollution, EDXRF

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“…Octopus has been processed and sold in the local market and can be exported (Guard 2009). Local coastal communities of Tanzania mainly deal with artisanal fishing for White-spotted octopus (Octopus chromatus Heilprin, 1888), common octopus (O. vulgaris Cuvier, 1797), and Day octopus (O. cyanea Gray, 1849) as their source of employment and income generation (Guard and Mgaya 2002;Guard 2009;Mshana and Sekadende 2014) and protein source (Bultel et al 1950;Estevez et al 1996;Gestal et al 2007).…”

Section: Introductionmentioning

confidence: 99%

“…Many O. cyanea is mostly found on the East African coast and Madagascar to south-eastern Asia and Hawaii (Guard and Mgaya 2002;Benbow et al 2014). O. cyanea is a predatory cephalopod foraging and feeding on other invertebrates, such as crustaceans (Mshana and Sekadende 2014). The size of male and female O. cyanea differs at sexual maturity; females may reach 0.6 kg to 5 kg at spawning, while males may reach 300 g at sexual maturity (Van Heukelem 1973).…”

Section: Introductionmentioning

confidence: 99%

Investigation on parasites of Octopus cyanea in Tanzania

MSONGOLE

Kimbita

2020

Indo Pac J Ocean Life

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Abstract. Msongole PL, Kimbita EN. 2020. Investigation on parasites of Octopus cyanea in Tanzania. Ocean Life 4: 24-36. This study aimed to investigate parasites in Octopus cyanea (Gray, 1849) or Day octopus along the Indian Ocean of the Tanga region in Tanzania. Information from fishermen was required to determine their awareness of octopuses' parasitic infections. Twenty-five percent (25.3%) agreed on the presence of parasites in octopus skin and muscles, but these were not observed during laboratory investigation. Gamogony and sporogony of Aggregata sp. (Apicomplexa: Aggregatidae) were observed during histopathological examination of the digestive tracts of octopuses collected along the Tanga coastal area. The O. cyanea was infected with the coccidian parasite, Aggregata spp., with a prevalence of 41.1% (23 of 56 hosts examined). Oocysts were sub-spherical in the mucosa wall of the intestine and caecum, measuring 263-279 ?m. Sporocysts were smooth?surfaced, dark?staining, spherical, typically 10-15 ?m wide, and contained 9-22 banana-shaped sporozoites with a size of 2-6 ?m long and 0.2-0.3 ?m wide. The coccidian infection in octopuses is accompanied replacement of the infected cells with sporocysts. Parasite infection of Aggregata spp. was not significantly correlated with the weight of the octopus, study site, or sex of the host. Molecular analysis was used to confirm the parasite species, in which 68% of samples were positive. Molecular characterization revealed that the coccidian was the Aggregata octopiana (Schneider, 1875) Frenzel, 1885. Alignments revealed that the coccidian from O. cyanea resembled 89% with A. octopiana isolated from common Octopus in Spain. Despite the presence of A. octopiana in O. cyanea, the parasite does not cause effects on consumers unless the octopus is infected with another epizootiology agent.

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Assessment of Heavy Metal Pollution in Octopus cyanea in the Coastal Waters of Tanzania

Cited by 10 publications

References 19 publications

Bioaccumulation and public health implications of trace metals in edible tissues of the crustaceans Scylla serrata and Penaeus monodon from the Tanzanian coast

Bioaccumulation and public health implications of trace metals in edible tissues of the crustaceans Scylla serrata and Penaeus monodon from the Tanzanian coast

Levels of selected toxic and essential elements in fish and oysters from Western Indian Ocean, Coast of Tanzania

Investigation on parasites of Octopus cyanea in Tanzania

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