Species Composition, Abundance And Distribution Of Jellyfish In The Coastal Waters Of Penang National Park And Manjung
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Date
2012-05
Authors
Chuah, Chern Chung
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
A study of species composition, abundance and distribution of jellyfish population in the Straits of Malacca, Malaysia, was conducted for 14-months around the coastal waters of Penang National Park (PNP), Penang (November, 2009 to December, 2010) and Manjung, Perak (September, 2009 to October, 2010). Towing and scooping methods were used for sample collection using a fishing boat cruising at the speed of approximately 2.5 nautical knots during neap tide. The scooping method used visual observation to detect jellyfish on the water surface. Meanwhile towing method required a custom-made trawl towed behind the boat for submerged jellyfish sample. A total number of 5 jellyfish species from 5 genera were identified, namely: Phyllorhiza punctata, Chrysaora sp., Rhopilema sp., Chiropsoides buitendijki, and Carybdea morbakka. The dominant Chrysaora sp. contributed up to 95.42% (PNP) and 97.66% (Manjung) of the total jellyfish catch. The maximum jellyfish number recorded was 57.07±12.37 individuals/1000m3 in May, 2010 (PNP) and 475.70 individuals/1000m3 in October, 2010 (Manjung). A clear seasonal jellyfish blooming was observed in September, 2009 and October, 2010 at Manjung waters. In PNP, no occurrences of jellyfish bloom but their presence were observed throughout the whole sampling periods. Physico-chemical parameters recorded at PNP and Manjung were within the normal ranges. In PNP, pH, temperature, salinity, conductivity, dissolved oxygen, total suspended solid, biological oxygen demand, and chlorophyll-a varied between 8.09 - 8.97, 29.12°C - 32.06°C, 28.56ppt - 30.30ppt, 47.05μS/cm - 53.36μS/cm, 4.26mg/L - 6.70mg/L, 36.60mg/L - 80.53mg/L, 0.38mg/L - 3.19mg/L and 0.33mg/L - 2.41mg/L, respectively. For nutrient, nitrite, nitrate, ammonia and phosphate varied between 0 – 0.03mg/L, 0 – 0.05mg/L, 0 – 0.02mg/L and 0 – 0.01mg/L, respectively. Meanwhile, the water qualities parameters in Manjung coastal waters recorded pH, temperature, salinity, conductivity, dissolved oxygen, total suspended solid, biological oxygen demand, and chlorophyll-a in the range of 6.99 - 8.50, 30.14°C - 32.76°C, 25.39ppt - 29.62ppt, 44.69μS/cm - 51.85μS/cm, 4.87mg/L - 6.96mg/L, 26.88mg/L – 63.46mg/L, 0.36mg/L - 3.46mg/L, and 0.15mg/L – 1.40mg/L, respectively. For nutrient, nitrite, nitrate, ammonia and phosphate fluctuated within 0 – 0.03mg/L, 0 – 0.04mg/L, 0 – 0.05mg/L and 0 – 0.01mg/L, respectively. The concentration of nutrients was positively correlated with the abundance of jellyfish in the PNP (nitrite, r= 0.415, p< 0.01; nitrate, r=0.263 p< 0.01; ammonia, r=0.235, p< 0.05) and in Manjung (nitrite, r= 0.246, p< 0.05; nitrate, r=0.419 p< 0.05; ammonia, r=0.589, p< 0.01).
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Keywords
Species composition, abundance and distribution , jellyfish population in the Straits of Malacca