Haiku Stream Data: In Situ Data

Turbidity

Turbidity is a measure of water clarity. Higher turbidity indicates cloudier water due to suspended particles like sediment (for example silt and clay) organic matter, or algae

Dissolved Oxygen

Dissolved oxygen (DO) is vital for the survival of fish, aquatic plants, and other organisms. Just like humans need air to breathe, aquatic life depends on dissolved oxygen for survival. Healthy high dissolved oxygen levels indicate a well-functioning ecosystem, while low dissolved oxygen levels can signal pollution and poor water quality. Low dissolved oxygen levels can also lead to the proliferation of harmful bacteria and algae, making the water unsafe for swimming, fishing, and other water activities. While a single “typical” dissolved oxygen (DO) level isn’t applicable across all Hawaiian streams, a generally desirable range for healthy streams falls between 6 milligrams per liter (mg/L) and 8 mg/L, because this range supports a variety of aquatic life.

Conductivity

While not a standalone indicator of safety for swimming, long-term trends in conductivity and specific conductivity can help identify water quality concerns and potential pollution sources. This information can be used to guide efforts to protect stream health. Possible sources of increased conductivity include:

Natural Mineral Content: Streams flowing through areas with naturally high mineral content may have higher baseline conductivity [1].
Pollution Sources: Human activities like road runoff, fertilizer application, or wastewater discharge can introduce dissolved salts and minerals, raising conductivity [2].

Elevated conductivity levels can suggest contamination by pollutants such as heavy metals, which pose health risks to those swimming, fishing, or engaging in other water activities.

Water pH

pH is a measure of acidity (or basicity) on a scale from 0 to 14, with 7 being neutral. Freshwater streams should ideally have pH levels between 6.5 and 8.5 to support aquatic life and be safe for recreational use (U.S. Environmental Protection Agency [EPA], 2022). Deviations from this range can indicate the presence of pollutants or other environmental issues that may harm aquatic organisms and pose risks to human health.