Land reclamation in Penang began two decades ago and is still rampant with
large reclamation projects planned to be executed in the near future. The present study
provides the first information on effects of land reclamation in Penang towards the coastal
macroinvertebrates. This study assessed the abundance, diversity, and evenness of
coastal invertebrates assumed to be the foremost affected when land is reclaimed. Three
kinds of areas were focused on: reclaimed, unclaimed (adjacent to reclaimed), and
undisturbed. A total of 53 species of macroinvertebrates from 10 classes (Gastropoda,
Bivalvia, Polychaeta, Malacostraca, Maxillopoda, Echinoidea, Polyplacophora,
Branchiopoda, Scaphopoda, and Holothuroidea) were sampled. Reclaimed areas were
moderately rich in species averaging 11 species compared to 7 species in adjacent and
14 in undisturbed areas. Species richness was the highest in Teluk Aling (an undisturbed
area) with 22 species, and was the lowest in Gurney Drive (an adjacent area) with 2
species. The average species diversity and evenness on reclaimed land was the lowest
with values of 1.9974 and 0.5787, respectively. The diversity was higher by 5.07% in
adjacent areas and by 22.92% in undisturbed areas compared to reclaimed areas.
Species evenness was 29.75% higher in unreclaimed areas and 17.87% higher in
undisturbed areas compared to reclaimed areas. Land reclamation reduces species
diversity and evenness, and to a lesser extent, species richness.
The purpose of this paper was to provide a practical guide assisting field workers in identification and interpretation of frequently occurring bioerosional textures created in limestone by intertidal organisms along the coasts of Langkawi Islands, Malaysia. The discussion follows the textural succession from the supratidal down to the lower intertidal zone. Traces left by lichens, boring sponges, molluscs (littorinid snails, the chiton Acanthopleura, the bivalve Lithophaga) and the echinoid Echinometra are illustrated. Products of bioconstructing organisms, specifically oysters and barnacle are also described. Ecological tolerance of each group is given.
This study presents the first ever data of extracting chitin from the Chiton shell, which was then converted to the soluble chitosan by soaking in the 45% NaOH solution. The obtained chitin and chitosan were characterized by the seven different methods. Antioxidant activity of the extracted chitosan was also evaluated using the two methods. The shell content was divided into calcium carbonate (90.5 %), protein (5.2%), and chitin (4.3 %). Due to the results of element analysis and 1H NMR, the final degree of deacetylation of chitosan was 90%. Surprisingly, a significant amount of Fe was accidentally found in the shell after demineralization, and removed from the solution through the filtering. Nonetheless, remained Fe in the extracted chitin and chitosan was 20 times higher than those previously reported from the shell of shrimps and crabs. Presence of this amount of Fe could describe why the produced chitosan was darker compared to the commercial chitosan. Antioxidant activity tests showed that the IC50 of the extracted chitosan was higher than one estimated for the commercial chitosan. Antioxidant activity of the extracted chitosan is even better than the commercial version and may be used in pharmaceutical industry as a source of antioxidant.