Lower Estuary: Day in the Life of the Hudson & Harbor 2020

Summary

The video explores the dynamic Hudson River estuary, focusing on water quality and fish species in its diverse ecosystems. Participants collect data on turbidity, salinity, dissolved oxygen, and water temperature, learning how these factors affect the river's health and its aquatic life. With contributions from various partners, viewers are guided through hands-on sampling at different locations, from Yonkers to Newburgh. The video emphasizes the importance of these parameters in understanding fish behavior and the river’s ecosystem, offering a comprehensive look at the estuary's environmental conditions.

Takeaways

• 😀 The Hudson River Estuary is a dynamic system with a mix of freshwater and saltwater, influenced by tides and the Atlantic Ocean.
• 😀 Turbidity is an important water quality parameter, referring to the cloudiness or murkiness caused by suspended particles in the water.
• 😀 The turbidity tube and Secchi disc are used to measure turbidity, with the goal of determining how far light can penetrate the water.
• 😀 Algae, plankton, mud, and sediments are common contributors to turbidity in estuarine waters.
• 😀 Fish species diversity in the Hudson River is significant due to the mixing of fresh and saltwater, providing varied habitats.
• 😀 Striped bass, Atlantic silversides, white perch, and flounders are some of the fish species commonly found in the estuary.
• 😀 Salinity is a key indicator of the river's proximity to the ocean, with readings affecting the types of fish and other organisms found in different regions of the estuary.
• 😀 The Day in the Life program helps gather data on fish species distribution, salinity levels, turbidity, and other water quality parameters.
• 😀 Dissolved oxygen is critical for aquatic life, with measurements taken using reagents to determine the oxygen content in the water.
• 😀 Understanding the difference between a fish's preference and tolerance ranges helps scientists better predict and analyze species distribution in the Hudson River.

Q & A

What is turbidity, and why is it important in this context?

Turbidity refers to the cloudiness or haziness of water caused by suspended particles like sediments, algae, and plankton. It's important because it can affect water quality and the health of aquatic ecosystems, and it provides insights into the environmental conditions of the Hudson River.

How do scientists measure turbidity in the Hudson River?

Scientists use a simple tool called a turbidity tube, which contains a black and white checkerboard disc at the bottom. The water sample is filled into the tube, and the goal is to determine how far one can see through the water to the disc. The turbidity is measured by the depth of the water at which the disc becomes visible.

What factors contribute to the high turbidity in the Hudson River?

The Hudson River has high turbidity due to several factors, including a high sediment load, turbulent mixing from fresh and salty water, plankton presence, and nutrient-rich water that supports decomposing plant matter.

What is the significance of fish species diversity in the Hudson River?

The Hudson River's mix of fresh, brackish, and salty water supports a wide diversity of over 250 fish species. The changing water conditions make it essential to understand the fish's preference ranges (optimal conditions) and tolerance ranges (survival conditions) for better ecosystem management.

What is the role of turbidity in fish survival?

Turbidity helps fish by providing camouflage, which can protect them from predators. The nutrients in turbid water also serve as a food source for fish, contributing to the river's biodiversity.

How do scientists measure salinity in the Hudson River?

Salinity is measured using a hydrometer, which floats based on the density of the water. Saltwater is denser than freshwater, so the hydrometer's plastic arm will float higher in saltwater. The salinity level is recorded in parts per thousand (ppt).

Why is the measurement of dissolved oxygen important?

Dissolved oxygen is crucial because it indicates the health of the water. Just like humans need oxygen to breathe, aquatic animals also need oxygen to survive. The amount of oxygen in the water can tell us about the overall water quality and ecosystem health.

What tools are used to measure dissolved oxygen in the Hudson River?

Scientists measure dissolved oxygen using a standard titration method. They add sodium thiosulfate to a water sample, drop by drop, until the sample clears. Each drop represents one part per million (ppm) of dissolved oxygen.

How do tides affect the Hudson River ecosystem?

Tides bring the influence of the Atlantic Ocean into the river, affecting salinity, water levels, and nutrient distribution. The Hudson River is an estuary, so the twice-daily tides play a significant role in the mixing of fresh and saltwater, influencing the habitats of aquatic species.

What fish species were commonly found during the Day in the Life of the Hudson River event?

Common fish species observed included Atlantic silversides, striped bass, white perch, spottail shiners, and bluefish. These species thrive in different parts of the river, depending on salinity, temperature, and other environmental factors.