摘要
<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 55) followed by medium (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 30) and highly (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.</span>
<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 55) followed by medium (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 30) and highly (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.</span>
作者
Aroloye O. Numbere
Aroloye O. Numbere(Department of Animal and Environmental Biology, University of Port Harcourt, Choba, Nigeria)
