Pengambilan Sampel Benthos Pada Air Permukaan || S&PRL UPT Lab Ling Tanah Bumbu

Summary

This video documents the process of benthic sampling from a river in Desa Sungai Lembu. The team uses an Ekman grab to collect benthos, with careful measurements of water parameters such as current speed, dissolved oxygen (DO), pH, and temperature. The collected samples are then sieved, preserved in formalin, and prepared for identification in the lab. The process emphasizes accuracy in data collection, including GPS coordinates and field documentation. The video captures the meticulous fieldwork and the procedures used to ensure proper preservation and subsequent analysis of the benthic organisms.

Takeaways

• 😀 Benthic sampling is conducted in a river near the village of Sungai Lembu.
• 😀 Sampling involves using an Ekman grab to collect benthos from the riverbed.
• 😀 The benthic samples are marked with a tag containing location data before collection.
• 😀 After the Ekman grab is deployed, it is lowered to the riverbed, and a weight is dropped to close the grab and secure the benthos sample.
• 😀 The collected samples are transferred into plastic bags for further processing.
• 😀 Several environmental parameters are recorded during the sampling process, including water velocity, pH, temperature, and dissolved oxygen (DO) levels.
• 😀 Water velocity is measured directly, and in this case, it is 0.3 m/s.
• 😀 pH is measured using a calibrated pH meter, with readings of 7.38 and 7.39 taken at two different times.
• 😀 A DO meter is used to measure dissolved oxygen levels, contributing to understanding the aquatic environment.
• 😀 Samples are sieved using mesh sizes 1 and 2 to separate the benthos before placing them in sample bags.
• 😀 The samples are preserved with 10% formalin and will later be analyzed and identified in the laboratory.

Q & A

What is the purpose of the sampling process described in the transcript?

The purpose of the sampling process is to collect benthos, a type of biota, from the riverbed of Sungai Lembu. This process involves using an Ekman grab to collect sediment and benthic organisms for further analysis.

How is the Ekman grab used in the sampling process?

The Ekman grab is lowered into the riverbed until it touches the substrate. Once it reaches the bottom, a weight is dropped to close the grab's jaws, trapping the sediment and organisms inside. The contents are then transferred into a plastic bag for further processing.

What measurements are taken to support the benthic sampling process?

Several environmental parameters are recorded, including the current velocity (0.3 m/s), dissolved oxygen (DO) levels, pH, and water temperature. These measurements help contextualize the benthic sample and provide important data for analysis.

Why is the Ekman grab used in benthic sampling?

The Ekman grab is used because it is effective at collecting samples from the riverbed by trapping sediment and benthic organisms. Its design allows for precise collection without disturbing the surrounding substrate too much.

What is the procedure for measuring the river's current velocity?

The current velocity is measured using a method involving direct observation and instrumentation, yielding a value of 0.3 m/s, which is noted in the field form as part of the data collection.

How is the pH level of the water measured during the sampling?

The pH level of the water is measured using a calibrated pH meter. The meter is first calibrated with buffer solutions of pH 4 and 7, and then the pH of the water is measured at two different points during the sampling process.

What is the role of the dissolved oxygen (DO) measurement in the sampling?

Dissolved oxygen (DO) is a crucial parameter for assessing the health of aquatic ecosystems. It is measured during the sampling to provide insights into the water quality and the potential impact on benthic organisms.

What steps are involved in preparing the benthic samples for transport to the lab?

After the samples are collected with the Ekman grab, they are sieved using a two-mesh system to separate finer materials. The benthos is then placed into a sample bag, which is treated with 10% formalin for preservation before being transported to the laboratory for identification.

Why is formalin used in the preservation of the benthic samples?

Formalin is used to preserve the benthic samples by preventing decay and maintaining the integrity of the organisms for later identification and analysis in the laboratory.

What is the significance of using a multi-mesh sieve in the sampling process?

The multi-mesh sieve helps to separate different sizes of sediment and benthic organisms, ensuring that only relevant samples are retained for further analysis. The different mesh sizes (meshes 1 and 2) allow for more efficient separation of materials based on size.