Biota of Lakes and Reservoirs - Hydro-Environmental Analysis: Freshwater Environments - page 424

Lake Erie

5 km

N

Detriot

Windsor

Lake Erie

Toledo

Cleveland

20 km

N

FIGURE 15.12 October 2011 satellite image of a toxic algae bloom (primarily Microcystis ) in Lake Erie.
(From NOAA Landsat-5 Imagery.)

Center for Disease Control (CDC) lists the possible human impacts from the consumption of these
toxins, including stomach and intestinal illness; breathing dificulties; allergic responses; skin irri-
tation; liver damage; and neurotoxic reactions, such as tingling ingers and toes. Figure 15.12 is an
illustration of an extremely large HAB (primarily Microcystis ) that occurred in Lake Erie during
early October 2011 and was captured by satellite imagery.
Another toxic algae is the haptophyte, or golden algae, P. parvum . These algae are more com-
mon in brackish waters and can cause marine toxic algal blooms. While not considered a public
health threat, they are believed to produce a number of toxins, collectively known as prymnesins,
which include an ichthyotoxin (toxic to ish, Sallenave 2010) that ruptures gill membranes. In Texas,
this alga became a major issue as a result of massive ish kills at Dundee State Fish Hatchery. The
golden algae has caused ish kills in 33 Texas reservoirs and has invaded reservoirs and river sys-
tems in 15 other states, including Alabama, Arizona, Arkansas, California, Washington, Hawaii,
New Mexico, Wyoming, North Carolina, South Carolina, Florida, and Georgia (Sager et al. 2008,
cited by Sallenave 2010).

15.3.1.1.3 Methods for Enumeration
15.3.1.1.3.1 Direct Enumerat ion One method for quantifying phytoplankton is direct enumera-
tion. This is a typically laborious process that initially involves collecting whole-water samples
and then concentrating these samples (e.g., see Porter et al. [1993] for protocols used in the U.S.
Geological Survey's National Water-Quality Assessment Program [NAWQA]). The samples are
then counted via microscopy. Often, counting chambers are used to facilitate the process, such as
the Sedgewick/Rafter counting cell (Figure 15.13).