Reduction in fish

The external costs of using the flame retardants are caused by long-term adverse impacts in the aquatic environment (reduction in fish production capacity) and severe nuisance in humans (7) and potentially disturbance in human development (Z). There are as of yet no economic values derived for the latter two but we express the values as Y and U. For reduction in fish production capacity the value from the literature is 1 per kilogram fish [37, 38]. And in our example, we assume that the production capacity is reduced by some 10 tonnes of fish. 

Payne, J., D. Malins, S. Gunselman, A. Rahimtula and P. Yeats. DNA oxidative damage and vitamin A reductions in fish from a large lake system in Labrador, Newfoundland, contaminated with iron-ore mine tailings. Mar. Environ. Res. 46 289-294, 1998. 

In the La Cloche Mountain area of Ontario, 24% of lakes surveyed have no fish at all. 56% of these fishless lakes are known to have suffered a reduction in fish species composition. Small-mouth bass, walleye, white suckers, norther pike, lake trout, lake herring, perch and rock bass have been affected. 

The biological turnover of organic (lipophilic) elements like Hg is generally slow the half-life for Hg in pike is several years. This is important in remedial contexts. A liming may increase a lake s pH from 5 to 6 in a couple of days but the Hg-reduction in fish, that may be linked to this measure. Will proceed slowly. If a higher pH is maintained, then this will influence a number of chemical and biological conditions in the lake, and also the Hg uptake in fish. The Hg-concentration in fish will adapt to the new conditions, but this will take a relatively long time. 

Omega-3 fatty acids (eicosapentaenoic acid and docosa-hexaenoic acid), the predominant fatty acids in the oil of cold-water fish, lower triglycerides by as much as 35% when taken in large amounts. Fish oil supplements may be useful for patients with high triglycerides despite diet, alcohol restriction, and fibrate therapy. This effect may be modulated thru PPAR-a and a reduction in apolipoprotein B-100 secretion. Omega-3 fatty acids reduce platelet aggregation and have... 

Metabolism of trimethylamine oxide in fish muscle involves an enzyme-catalyzed oxidation-reduction reaction. The enzyme responsible for the conversion of trimethylamine oxide to trimethylamine is known as trimethylamine-W-oxide reductase. This enzyme acts on nicotinamide adenine dinucleotide (NADH) and TMAO to produce NAD+, trimethylamine and water (Fig. 13.13.1). TMAO acts as the oxidizing agent and is reduced, while NADH undergoes oxidation as the reducing agent. 

DDT and some of its breakdown products are relatively resistant to breakdown by enzymes and higher organisms found in the soil and are therefore highly persistent in soil, sediment and biota [54]. Despite significant reduction in the use of DDT in the Ebro since the 1960s, DDT still continues to cycle in the ecosystem, with high levels widely detected in both sediments and fish [47, 51, 52]. 

Studies of 30 to 60 days duration with three comparatively sensitive species of freshwater fishes demonstrated that concentrations of >1 and <3 pg Cd/L in water of low alkalinity caused reductions in growth, survival, and fecundity of brook trout (Salvelinusfontinalis), the most sensitive species tested (Table 1.3). Under conditions of increasing alkalinity, the maximum allowable cadmium concentration range for brook trout increased to >7 and <12 pg/L a similar case was made for the walleye (Stizostedion vitreum vitreum Table 1.3). 

O. mykiss 0.5 or 2.0 Exposure of 3-week-old hatchlings for 21 days. Dose-dependent increase in TBT accumulation and growth reduction. Treated fish had greater swimming stamina than controls but lacked circular orientation typical of controls. TBT tissue concentrations in head and body at 21 days ranged from 1.5-2.0 mg/kg FW vs. 0.05-0.11 in controls 46... 

---