Impact of Human Disturbance on Fiddler Crab (Uca tangeri) Burrow Morphology, Distribution and Chemistry at Eagle Island, Niger Delta, Nigeria

Document pages: 12 pages

Abstract: Fiddlercrabs are described as ecosystem engineers because of their burrow constructingability. It was hypothesized that human activity will impact crab burrows. Thestudy area was delineated into lowly, medium and highly impacted plots. Crabholes 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 resultindicates that burrow width was significantly different between impacted plots(P 0.05), but highly impacted plot has the longest lengthwhile lowly impacted plot has the shortest length. Again, the surface area ofcrab burrow varies significantly (P 2) followed by medium (390.30 ± 57.65cm2) and high (265.16 ± 30.85 cm2) impacted plots.Similarly, lowly impacted area has more number of burrows (n = 55) followed by medium (n = 30) and highly (n = 23)impacted plots. Highly impacted plot had the highest Cd and Pb concentrationwhereas lowly impacted plot had the highest Zn concentration. This implies thatburrow morphology and chemistry exemplify the level of anthropogenic impact.