Fish kill

One of the major effects of acidic deposition is felt by aquatic ecosystems in mountainous terrain, where considerable precipitation occurs due to orographic lifting. The maximum effect is felt where there is little buffering of the acid by soil or rock structures and where steep lakeshore slopes allow little time for precipitation to remain on the ground surface before entering the lake. Maximum fish kills occur in the early spring due to the "acid shock" of the first meltwater, which releases the pollution accumulated in the winter snowpack. This first melt may be 5-10 times more acidic than rainfall. 

Altliough ail accurate assessment could not be tnade itnmediately, tlie Ashland spill look a heavy toll on tlie wildlife of the Ohio River Valley. More tluiii 5000 waterfowl were killed when their feathers became contaminated witli oil. Birds tliat e. perience oil conlaminalion lose tlieir natural insulation and buoyancy and cither drown or freeze to death. In addition, a massive fish kill was e. pectcd in the spring when the ri cr entered a new cycle. 

As noted earlier, OPs are known to be highly toxic to aquatic invertebrates and to fish. This has been demonstrated in field studies. For example, malathion applied to watercress beds caused lethal intoxication of the freshwater shrimp Gammarus pulex located downstream (Crane et al. 1995). Kills of marine invertebrates have been reported following the application of OPs. Accidental release of OPs into rivers, lakes, and bays has sometimes caused large-scale fish kills (see Environmental Health Criteria 63). 

HPLC has also been utilized in more complex food chain transfers. It has been known for some time that the toxins can be responsible for fish kills in the Bay of Fundy 18). The vectors for these fish kills are zooplankton that feed on toxic dinoflagellates. In two related studies (79 Sullivan, unpublished), HPLC was utilized to investigate the transport of toxins from dinoflagellates to zooplankton and then to fish. The HPLC method is ideally suited for this since only very small sample sizes (ca. 100,000 dinoflagellate cells) are required. 

This organism, an unarmored dinoflagellate, has been observed in sporadic outbreaks in west coast Florida waters and in other nearshore waters of the Gulf of Mexico (1). Outbreaks have a considerable social, public health and economic impact because of fish kills. For example, the outbreak that lasted for three summer months during... 

Many lakes also suffer from a phenomenon called episodic acidity. Episodic acidity means that most of the time the lake has a pH within acceptable levels. But occasionally, the pH of the lake becomes much lower when heavy rainstorms or snow melts bring in large amounts of runoff. Episodic acidity sometimes results in large fish kills. The Northeastern part of the United States and Canada are especially hard hit due to the poor buffering capacity of the soil in those areas. 

According to the Illinois Environmental Protection Agency (IEPA), a series of gas blowouts has occurred at two waste injection wells in the state (Brower el al., 1989). In each case, well operators were injecting concentrated hydrochloric acid into a dolomite bed. At its plant near Tuscola, the Cabot Corporation injects acid waste from the production of fumed silica into the Cambrian Eminence and Potosi Formations below 5 000 ft (1 500 m) depth. Allied Chemical Corporation injects acid into the Potosi formation below about 3 600 ft (1 100 m). The acid, which is contaminated with arsenic, is a byproduct of the manufacture of refrigerant gas. Since some of the blowouts have caused damage such as fish kills, there is environmental interest as well as operational concern in preventing such accidents. 

Van Hoof, F. and M. Van San. 1981. Analysis of copper, zinc, cadmium and chromium in fish tissues. A tool for detecting metal caused fish kills. Chemosphere 10 1127-1135. 

Kariya, T., K. Kawase, H. Haga, and T. Tsuda. 1968. Studies on the post-mortem identification of the pollutant in the fish killed by water pollution — VB. Detection of nickel in the fish. Bull. Japan. Soc. Sci. Fish. 34 385-390. 

Single ip injection of 30 mg PCB 118/kg BW to immatures. Fish killed 4 days later and liver analyzed Liver EROD (7-ethoxyresorufin O-deethylase) activity was 5.6 times higher than controls AHH activity was 2.7 times higher than controls 5... 

Toxaphene is extremely toxic to freshwater and marine biota. In laboratory tests of 96-h duration, 50% mortality was recorded for the most sensitive species of freshwater and marine teleosts, marine crustaceans, and freshwater insects at nominal water concentrations of less than 10 pg/L of toxaphene, and, in several cases, less than 1 pg/L (Table 27.2). Bioassays of longer duration, based on exposure of aquatic organisms for the entire or most of the life cycle, produced significant adverse effects on growth, survival, and reproduction at toxaphene concentrations between 0.025 and 1.0 pg/L (Table 27.3). Toxaphene was most toxic to freshwater fishes in soft water at elevated temperatures (Saleh 1991). Based on its high toxicity and extensive use, it is not surprising that toxaphene was considered a major cause of nationwide fish kills in 1977 (USEPA 1980b). 

U.S. Environmental Protection Agency (USEPA). 1980b. Fish Kills Caused by Pollution in 1977 Eighteenth Report. U.S. Environ. Protection Agency Rep. 440/4-80-004. 73 pp. 

Problem definition Joe, a water resource specialist calls to tell you that a huge fish kill has just occurred in one of the rivers in your state. The two of you will work as a team to determine what has killed over 300,000 fish. 

Information gathering Fish kills are often due to natural phenomena, such as algal blooms that can deplete the oxygen content of the water. This one was especially severe. 

Information gathering Fish kills may also be caused by toxic industrial discharges or agricultural run-off that contains high levels of fertilizers, herbicides, or pesticides. Sometimes old barrels of industrial waste dumped in the river years ago begin leaking into the river. Such barrels occasionally come to the surface. Solutions of toxic heavy metals, such as chromium, are sometimes dumped surreptitiously into rivers. The Environmental Protection Agency (EPA) has published many methods for pesticides, herbicides, etc. in water. 

Formulating a hypothesis Though it seems far-fetched, CO poisoning is hypothesized to be the cause of the fish kill. 

Interpretation/report The spectra of the two different blood samples are different (Fig. 21.12). The Oximeter, though calibrated for human blood, indicates 60-70% of the hemoglobin in the fish from the fish kill is carboxyhemoglobin. The control fish showed less than 10%. Human fatalities have carboxyhemoglobin levels above 30% ... 

Commentary This problem demonstrates that potential health issues receive high priority. While many possible sources of the fish kill were identified, they were likely approached simultaneously and the most obvious sources were eliminated from consideration first. While there may be some ethical concerns with the use of live fish as a pollution detector, it is important to solve this problem in the most efficient manner possible, at least until it is determined whether this is a human health concern. 

Because of the persistence of endrin in the environment and its potential to bioconcentrate significantly in aquatic organisms, there has been continued concern over the levels of endrin in fish and shellfish. This concern, however, appears to be limited primarily to specific sites where endrin was used heavily in agriculture or was discharged by industrial plants. In 1963, at the height of agricultural endrin use, endrin levels in catfish poisoned by endrin exceeded 4 ppm (4,000 ppb) during a fish kill (Mount and Putnicki... 

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