The blue swimming crab (BSC) (Portunus pelagicus Linnaeus 1758), is found across Asia, and Australia, Oceania, including Guam, Palau, and Tonga (Ng, 1998; Lai et al., 2010). The BSC is frequently found in maritime areas up to 40 m deep, on sandy to sandy-muddy substrates near reefs, mangrove forests, seagrass beds, and algal beds. Artisanal traps, trawls, beach seines, and crab gill nets are used to catch this crab (Ng, 1998). Crab meat is sold in local markets (fresh or frozen) and through for the crab-flesh canning business, which is particularly widespread in Southeast Asian markets (Lai et al., 2010). BSC fisheries have expanded rapidly since the early 1950s, due to the growing popularity of this crab species, with annual catch increasing dramatically (Shelley and Lovatelli, 2011). P. pelagicus exports, together with mud crab (Scylla spp), are presently rated third in Indonesia, behind tuna and shrimp, with a total value of US$153 million. Crab exports from Indonesia are supported by capture fisheries 65% of the time and aquaculture 35% (Central Bureau of Statistics, 2018). Because crab production still depends on nature, and because they are commonly found at the bottom substrates of estuaries, beaches, and oceans, where they are in regular contact with sediment, they may accumulate contaminants, including metals (Mazzei et al., 2014).
The Solo River and the Brantas River are two large rivers that flow into the northern coastal waters of East Java. Along these two rivers, there is a lot of agricultural, industrial, and residential activity (Roosmini et al., 2018). Consequently, these rivers receive waste from these activities, affecting species including BSC that inhabit the river’s estuary and adjacent area. There was no information available on the metal levels in this crab from the East Java coast. Previous studies have discovered significant amounts of metals in green mussels Perna viridis, cockles Anadara granosa, clam Meretrix sp. (Eshmat et al., 2014; Haryono et al., 2017; Fitra et al., 2018; Rayyana et al., 2019; Yona et al., 2021; Soegianto et al., 2021a,b), mud crab (Scylla serrata) (Soegianto et al., 2022) and fish (Ruaeny et al., 2015) from East Java’s estuaries and coastal waters. The metals most commonly measured by researchers in marine biota found in East Java’s coastal waters include Cu, Zn, Cr, Pb, Cd and Hg.
Metals are classified as essential elements (such as Zn, Cu and Cr) and non-essential elements (such as Hg, Cd and Pb). All organisms contain essential elements in their natural state. Higher concentrations of essential elements, on the other hand, can be toxic and even dangerous to organisms and humans. Meanwhile, non-essential elements are harmful even at low concentrations (Rajaram et al., 2020). Essential metals are required by organisms for enzymatic function and play important roles in various metabolic processes (Tuzen, 2009). However, excessive Cu consumption can result in skin allergies, liver illness, and neurological disorders (Rahman et al., 2012). Excess Zn consumption can cause electrolyte imbalances, poisonous reactions such as nausea, vomiting, stomach discomfort and cramps, severe diarrhea, and anemia, and inhibit copper absorption from the intestine (Fosmire, 1990). Long-term Cr exposure can cause allergic reactions, pneumonia, pulmonary cancer, digestive, heart, liver, and kidney illness, as well as neurological disorders (Chen et al., 2009). Hg has been reported to induce neurological disorders (Bernhoft, 2012). Cd causes adverse effects on the central nervous system, causing cell damage, inflammation, and renal failure (Rinaldi et al., 2017). In humans, Pb has been associated with immune and neurological system disorders and renal and hepatic impairment (Raknuzzaman et al., 2016; Park et al., 2017).
Evaluating metal levels in BSC along the East Java coast is important for public health. Therefore, the main aim of this study was to evaluate the concentrations of Cu, Zn, Cr, Pb, Cd and Hg in the muscle (flesh) of BSC caught off the coast of East Java, and the public health implications if the crab was consumed.
The result from this study shows that Portunus pelagicus from the Bali Strait had the lowest Cu, Zn, Cr, Pb, Cd and Hg concentrations compared to those from the Java Sea and the Madura Strait. The order of metal concentrations in BSC was Cu > Zn > Cr > Pb > Cd > Hg. The levels of six metals in BSC from all stations were less than the maximum allowable limits. However, Cr levels in BSC from the Java Sea and the Madura Strait exceeded the provisional tolerable weekly intake. All of the hazardous index values reported were greater than one, indicating that consumption of this crab from these locations appears to be hazardous to human health. Furthermore, because the Cr and Cd target cancer risk values were higher than 10− 4 , people who consume this crab from these locations may develop cancer after a lifespan of consumption.
Author: Agoes Soegianto
Published in journal: Marine Pollution Bulletin177 (2022) 113573
