Publications by authors named "Wen-Pei Tsai"

Marine organisms, especially top predators such as sharks, are susceptible to environmental pollutants like microplastics (MPs) and phthalate esters (PAEs), leading to ecosystem risks. Research on contamination in these apex species is, however, still limited. This study investigated MPs and PAEs in multiple shark species (Isurus oxyrinchus, Alopias superciliosus, Alopias pelagicus, Carcharhinus brevipinna, and Sphyrna zygaena) off Taiwan's eastern coast.

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The silky shark, Carcharhinus falciformis, is a cosmopolitan species commonly caught as a bycatch for longline fisheries. However, the genetic stock structure for the Indo-Pacific Ocean is not well-defined yet. Here, we used eight microsatellite loci to examine the genetic stock structure and effective population size of 307 silky sharks across 5 Indo-Pacific sampling locations.

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The shortfin mako shark () demonstrates low productivity and is thus relatively sensitive to fishing. Natural mortality () and fishing mortality () data are critical to determine their population dynamics. However, catch and fishing effort data are unavailable for this species in the South Pacific Ocean, making stock assessments difficult.

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This study assessed the concentrations of nine trace metals from juvenile C. falciformis caught from Indian Ocean. This study also discussed the metal pollution index (MPI) and bioconcentration factor (BCF) of each element, and their correlations.

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The silky shark (Carcharhinus falciformis) is the most abundant and widely distributed shark species in the marine system of tropical regions. However, it appears that there is limited information on USEPA 16 polycyclic aromatic hydrocarbons (PAHs) concentration in silky shark muscle tissue, which has together with the lack of a health risk assessment of human consumption of silky shark filets. The potential toxicity of PAHs in muscles of silky sharks and cancer and non-cancer risk of consumers were assessed.

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This present study documents the incidence of plastic digestion by shortfin mako shark (Isurus oxyrinchus), caught by the Taiwanese small-scale tuna longline fishery in the Northwest Pacific Ocean (between the northeast coast of Taiwan and Japan). In 20 stomachs of shortfin mako, nearly 10% of samples contained at least one piece of plastic debris. The ingested plastic debris was found in the forms of films (5.

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The presence of ultrafine plastics particles and its potential to concentrate and transport organic contaminants in aquatic environments have become a major concern in recent years. Specifically, the uptake of hazardous chemicals by plastics particles may affect the distribution and bioavailability of the chemicals. In this study, the adsorption of tetracycline (TC), an antibiotic frequently found in aquatic environments, on high-density polyethylene (PE) particles with the average size of 45 μm, was investigated.

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Article Synopsis
  • Multiple paternity has been confirmed in a variety of shark species, including oceanic sharks, indicating diverse reproductive strategies.
  • In a study on shortfin mako sharks, an average of 4.6 sires per litter was identified, although different software showed varying results (2.5 sires using GERUD).
  • These findings suggest that multiple paternity may be prevalent in shortfin mako sharks and should be incorporated into population studies for better projections and risk assessments.
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Focusing on 27 rare filter-feeding megamouth sharks (Megachasma pelagios) captured as a by-catch of drift gillnet fishery in the Pacific Ocean to the east of Taiwan, this study analyzes the concentrations of 24 elements in their muscle, discusses the bioaccumulation of each element and the correlation between different elements, and assesses the potential health risks of consuming megamouth shark muscle. Among the 24 elements, mean concentrations of Ga, Ag, Li, Bi, Hg, Co, and Cd were relatively low ranging from 10 to 10 mg/kg, those of Pb, Ba, Mn, Ni, As, Cr, B, Sr, Cu, and Zn ranged from 10-10 mg/kg, and those of Fe, Ca, Al, K, Mg, Ti, and Na were relatively high ranging from 10 to 10 mg/kg. The toxic element content index was most significantly correlated with the concentration of Cu.

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In this study, we investigate the microscale structure of shark skin denticles at abdomen (A) and fin (F) locations, analyze the roughness and wetting properties related to their microstructures, and evaluate the effect of the surface properties on early bacterial attachment and biofilm formation. Microstructural analysis by scanning electron microscopy and confocal laser scanning microscopy confirmed the length (A: 165-180 μm vs. F: 145-165 μm), width (A: 86-100 μm vs.

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Article Synopsis
  • The megamouth shark, a newly identified species since 1983, has been rarely observed, complicating our understanding of its movement and population dynamics.
  • Researchers analyzed tissue samples from 27 megamouth sharks in Taiwan and other regions to study genetic diversity and found no genetic structure, indicating a potentially interbreeding population.
  • Results suggest that the Kuroshio region may serve as a migratory route for these sharks, and future research should focus on more samples and satellite tracking to enhance knowledge of their global migration.
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