ผลกระทบจากการเลี้ยงหอยแมลงภู่ (Perna viridis) แบบแพเชือกต่อปริมาณตะกอนและสภาพแวดล้อมของดินตะกอนพื้นท้องทะเลบริเวณอ่าวศรีราชา จังหวัดชลบุรี

Abstract

The influences of green mussel (Perna viridis) raft culture on bottom sediments of Sriracha coastal areas were examined in three occasions during November 2016 to July 2017. Sediment traps were deployed at each time of field sampling period for determination of sedimentation from raft culture activities compared to reference site. Bottom sediment underneath the raft and from the reference site were also retrived using plexiglass hand correr by SCUBA diver for measurement of sediment qualities. Water was also collected from both sites for water qualities examination. The results indicated that mussel raft culture induced sedimentation with the rate was up to 255.26 g/m²/d and was much higher compared to that of the reference site (9.79-93.06 g/m²/d). The trapped sediment contained lower organic matter (OM) content (9.73-18.63 %) but higher nitrogen (10.67-13.98 mg N/g) compared to those of the reference site where the OM was ranging between 11.89-27.86 % and 9.83-11.18 mg N/g for nitrogen content. Bottom sediment under mussel raft contained higher OM (7.92-9.20 %) compared to reference site (~1 %). Nitrogen contents under mussel raft were much lower (0.28-0.39 mg N/g) compared to trapped sediment but these values were 5-10 times higher than that of the reference site (0.029-0.044 mg N/g). Water at the mussel raft contained higher nutrient contents for most of the sampling periods compared to that of the reference site where PO₄^3- was fluctuated between 0.23 and 0.97 µM, NH₄⁺ felt within the range of 2.02-9.22 µM and NO₂^- + NO₃^- were 0.32-3.28 µM. Mussel raft culture could induce sedimentation to surface sediment and also alter bottom sediment characteristics as well as water qualities. Thus, it is necessary to apply the regulation on culture area and raft culture practices to reduce impacts from mussel raft culture in Sriracha coastal area.