Given that the highest ambient turbidity calculated from the S.S. Badger’s coal ash slurry discharge, the turbidity/TSS ratio, and the dilution factor in the previous sections is 0.080 NTU, it appears highly unlikely that the turbidity contributed by this discharge would have an adverse effect on aquatic life present in the Lake Michigan ecosystem
Interesting argument to make, but his point does come across well...
Many drinking water utilities strive to achieve turbidity levels as low as 0.1 NTU.
Cool - good fact to know
inefficiently treated effluent is only a contributor to thepollution of surface waters
Yes - a contributor, but not the whole story. It is good to note that those things which we have significant control over are working properly to reduce the impact.
highly turbid water is difficult to disinfect and is oftenassociated with the growth of pathogenic organisms
Cool cool
The relationshipbetween turbidity andE. colipopulations could beclearly seen at both treatment plants during the samplingregime. Reductions in turbidity values at the DP wasaccompanied by lower bacterial counts
Good to know, for pathogens in drinking water aren't good at all!
A comparison of the 6 months of samplingacross both plants revealed the highest turbidity in Au-gust. This may be a result of surface runoff and soilerosion into receiving water bodies caused by the heavyrains experienced during this month.
Makes sense - not all turbidity (certainly not all!) can be associated with WWTP
All values obtained at both treatment plants werenot within specified guidelines
A good point to make - I hope the standard drinking water treatment helps reduce turbidity, also reveals the privledge of having access to clean drinking water
.40 ± 0.00
Still highly variable - shows that in a country with a less-well-functioning WW infrastructure, the river quality is still highly variable
Turbidity (NTU)
Similar things
02 ± 6.2
very high turbidity at discharge point
67 ± 0.38
Pretty much the same upstream and downstream levels, though still a little high (greater than 10)
Turbidity (N
Turbidity being higher than the Androscoggin indicates high wwtp activity
The additional sediments deposited during the era of land clearance may be continually re-suspended by tidal action, resulting in turbid waters that reduce light penetration to submerged aquatic vegetation and effectively prevent recovery of the benthic food web.
Boom key point
The apparent return of juvenile fish recruitment in Merrymeeting Bay suggests that these efforts are paying off, and indicates that suitable spawning habitat exists within the ecosystem.
Wooo optimism!
At best, the recovery of Merrymeeting Bay can be described as partial. Paper mills still discharge phosphorus and toxic compounds into the rivers, and N, S, Hg, and other pollutants enter via municipal wastewater treatment facilities, atmospheric deposition, and agricultural runoff
Yes - the regime change means low recovery
Much as individual species succumbed to the novel disturbance regime at different rates, various ecosystem parameters are recovering at different rates.
Great point - should include in the paper
he Merrymeeting Bay ecosystem, therefore, may support only half the nest sites that it did during the late 19th century.
But still indicates that a regime shift has occurred, that resources are not what they once were
In 2002, there were eighteen active nesting sites in Merrymeeting Bay and the lower Kennebec estuary, and fledgling success rose to an average of 1.2 eaglets per
Good news!...
ollution was also faulted, but its effects were judged limited at that time. Sawdust, however, was seen as a problem as "Great drifts of it settle down on bottoms that were well peopled with insects and other small creatures, and destroy all life. This deprives the fish of a portion of their feeding ground, and compels them to seek new pastures" (Foster and Atkins 1869).
Not an unreasonable assumption about the physical state of the water
Consequently, the construction of a permanent dam at Brunswick-Topsham on the Androscoggin by 1815 and the completion of the Kennebec dam at Augusta in 1837 caused the demise of the famous Kennebec salmon. N.W. Foster and C.G. Atkins (1869), the state fish commissioners, gave this account of the collapse of the Kennebec salmon fishery:
Wow - our dam in particular has a lot to answer for, caused a similar regime shift in the andro
population collapse
multiple regime shifts have happened in this bay
These patterns can be explained by deposition of suspended solids from industrial and municipal sources.
Interesting - TSS and turbidity are very closely linked. What does it mean now that we're getting heartening results back from our tests?
Each of these industries disposed of their raw wastes -including great quantities of sawdust, acids, fibers, and dyes - directly into the rivers
Optimism can come out because of the amount of turnaround we're seeing
By 1867, the effects of increased sedimentation were apparent. Vessels of 1000 tons destined for Brunswick and Topsham were required to "lighter up" (i.e., unload some of their cargo) five miles downriver because of shifting sands in the mouth of the Androscoggin
History of sedimentation - this is key in relation to the fish paper
From this database, we reconstructed a 40-year time series showing the number of nesting adult pairs and the number of fledglings utilizing Merrymeeting Bay and the lower Kennebec estuary.
Great - good resources available!
1979 and continuing to the present, the MDMR conducted juvenile fish censuses annually at 14 sites in the Merrymeeting Bay ecosystem (Squiers 2002).
Good to know - check on this
6% mortality of sac fry
In this table I see overall trends of high juvinile mortality, reduced growth rates, and fry mortality
Consider watershed condition when evaluating projects. Examine legacy of land use in watershed and determine how planned disturbance will contribute to cumulative effects. • Analyze other sources of sediment contribution to the watershed, such as grazing allotments, roads and culverts, and timber harvest areas. Reduce sediment loads from these areas if possible. • Restore tributaries and off-channel habitat to create potential turbidity refuges. • Determine whether knowledge of salmonid survival responses to turbid flows can be used to develop mixing zones, work windows, treatment systems, and buffers that will allow fish to perform their necessary life functions during project construction and operation. • Test a variety of existing and new technologies used to reduce TSS during road construction projects. Collect quantitative d
This is great advice, especially the first one. Nothing is said about WWTP, but I think I can easily make the case for turbidity there
Even low turbidities near 10-25 NTU and suspended sediment concentrations near 35 ppm can have deleterious effects on fish (Berg 1982; Sigler et al. 1984; Berg and Northcote 1985). Effects of Turbidity and Suspended Sediment on Salmonids (Lloyd 1987) 1) Reduced light penetration in lakes and streams 2) Associated with decreased production and abundance of plant material (primary production) 3) Decreased abundance of fish food organisms (secondary production) 4) Decreased production and abundance of fish
I think that different levels of turbidity will associate with different effects - this is suggesting a "dead zone", which could well be the case.
uspended material reduces the amount of light available to illuminate submerged objects and provide energy for plant photosynthesis. A change in light penetration through water may be expected to have far-reaching ramifications for whole aquatic ecosystems because of its influence on photosynthetic fixation of energy by aquatic plants (Davies-Colley and Smith 2000).
Yes - good to know, though I don't think we saw this in the andro
Turbidity and siltation causes an overall reduction in the number of bottom organisms, which results in changes to community structure, density, and diversity
Yes - so now I must determine the food web of the androscoggin and tie it in to turbidity measurements
Newcombe and MacDonald (1991) note that a change in sediment concentration can adversely affect secondary production by affecting algal growth, biomass, and species composition. Sediment can clog feeding structures, reducing efficiency and growth rates of filter feeders
I like this - secondary producers drop in number, causing yet another regime shift
n the presence of cover, daily predation rates were 10-75% lower.
So juviniles have more of a chance to grow, but adults have less feeding opportunities.
Gardner (1981) showed reduced feeding rates for bluegills in turbid waters. Feeding rates in a 3 minute period declined from 14 prey per minute in clear water to 11, 10, and 7 per minute in pools of 60, 120, and 190 NTU. Gardner suggested that high (>50 NTU) levels of turbidity would reduce energy intake (through decreased feeding rates) thus reducing production of fish populations
this study links it with energy intake - fascinating
redators
I think this means that the amt of predation was reduced and so signified decreased risk for the prey
At a turbidity level of 10 NTU, fish were noted to frequently misstrike prey items. A significant delay in the response of fish to introduced prey was noted at turbidities of 20 and 60 NTU. The acquisition of food resources in turbid waters may be reduced due to the effects of turbidity on behavior and vision
Strong point, that visibility creates behavior difference
Reduced visual clarity of waters may greatly affect the behavior of visual predators, notably fishes and piscivorous birds (Davies-Colley and Smith 2000). The reaction of salmonids to these factors is variable, as shown by the results reviewed below
Disruptor not only to the fish, but those who eat the fish as well. Could have very variable effects. What's the main takeaway?
prefer slightly to moderately turbid water for foraging, as reported in studies by Sigler et al. (1984) and Gregory (1988). This behavior may represent a trade-off between predation risk and bioenergetic demand and benefits of increased growth.
Good to know, but don't read too much into this - this is adaptability for variable conditions, and "moderately" does not mean "high" turbidity pulses.
as visual feeders, the effectiveness of salmonids in obtaining food is reduced by turbidity at levels as low as 20 NTU (Berg 1982).
Key insight, and reinforced by other studies, too
breakdown of social structure
what would the salmon literature be like, in a time of social breakdown from unidentifiable causes. It would be as if terrorists came upon us, or if the world by chance were polluted by extraterrestrial beings/
the
really indicates that anything in the 25-50 range severly impacts the fish
In tanks with mean turbidities of 167 NTUs or higher, no fish were found. Fish were found in tanks with lower turbidities (57 and 77 NTUs) at numbers near carrying capacity.
This data also ranges across multiple fish species, indicating that at least part of the trophic web was impacted. Steelhead and coho both feed on small insects, plankton, and small fish.
In many cases, salmonids avoid turbid water. In these instances, fish must successfully emigrate to areas of lower TSS. Factors affecting emigration may include availability and connectivity of patches with lower turbidity as well as the developmental stage of the fish (Sedell et al. 1990).
Essentially habitat fragmentation of the waterway. See below for actual data backing this up.
Sigler et al. (1984) identified a significant difference in growth rates between steelhead and coho in clear versus turbid water. As little as 25 NTUs of turbidity caused a reduction in fish growth. The implication of this finding is that fish subjected to turbidity in this experiment might experience increased probability of mortality
Reduced fish stock
Researchers have found an inverse relationship between fines (% sediment < 3 mm) and fry survival (Bjornn 1968; Phillips et al. 1975, Everest et al. 1987) with decreases in survival ranging up to 3.4% for each 1% increase in fine sediment < 0.850mm (Cederholm et al. 1981).
What qualifies as fine sediment? Is there any way to know if fine sediment is impacting turbidity?
Settleable solids may prevent eggs from receiving necessary oxygen and inhibit removal of waste products within the redd and may create a physical barrier to fry emergence. The greater the proportion of fine sediments in redds, the greater likelihood that fry hatching from normally developed embryos will be entrapped and unable to emerge (Everest et al. 1987)
Key point
Chronic turbidity during emergence and rearing of young anadromous salmonids could affect the quantity and quality of fish produced (Sigler et al. 1984). Organic matter entering substrate interstices depletes oxygen and reduces dissolved oxygen concentrations, harming eggs (
Ooooo organic matter in turbidity causes reduced spawning possiblilty
Cough frequency was elevated eightfold over control levels at 240 mg/l (turbidity of 30 NTUs). Berg (1982) examined the effect of a short-term sediment pulse (initially 3 days at 60 NTU, then a reduction on the seventh day to 10 NTU) on coughing frequency of juvenile coho. In two of four tests, coughing rates increased significantly when turbidity was raised to 60 NTU. As turbidity declined to 10 NTU, coughing declined or remained at pretreatment levels.
10 NTU seems to be a good cap for coughing levels
3,148 mg/l
how much is this in NTU?
Fish gills are delicate and easily damaged by abrasive silt particles. As sediment begins to accumulate in the filaments, fish excessively open and close their gills to expunge the silt. If irritation continues, mucus is produced to protect the gill surface, which may impede the circulation of water over gills and interfere with fish respiration
Fish choking to death, essentially, on the basis of too much turbidity
Turbidity is associated with a number of physiological effects in Pacific salmon (Berg 1982).
Could easily use analogy to extrapolate to eastern atlantic fish
changes to spawning and rearing habitat of salmonids.
Yes, but this would be hard to separate from dam activity causing much larger shifts in spawning
avoidance, changes in foraging ability, responses to predation risk, and reduced territoriality.
Same question as above
gill trauma, blood sugar levels, and osmoregulatory function.
have any of these been found in the androscoggin fish?
Can a watershed, given past management practices, provide the protection needed to salmonids at various life stages if additional sediment pulses are released?
That's a good question for me to ask myself of the Androscoggin - I think the answer will be yes, that the WWTP does a good job of providing physical water quality non-interference with fish
These coping strategies are partially defeated by the spatial distribution of roads: road runoff discharges
Wow - good to know and investigate
increased bioenergetic demands
I.E. more stress
reduces the carrying capacity of streams for salmonids
That makes sense - reduced ability to operate means less resources available means less fish
These results suggest that salmonids in a river system might seek out turbidity refugia when subjected to short-term pulses of sediment
Cool, but what level must the water get to long-term if it is to cause regime shift?
he overall buffering capacity of a system may be reduced by frequent sediment loading.
Important!
population decline over tim
Have the potential to cause a regime shift
kill individual fish, cause overall population reductions,
Most likely to cause a regime shift
Salmonid populations not normally exposed to high levels of natural turbidity or exposed to anthropogenic sediment sources may be deleteriously affected by levels of turbidity considered to be relatively low (18-70 NTU)
if species aren't used to it, of course alterations in the environment have the capacity to cause a regime shift
altering upslope and instream physical and biological processes
So this is just EOS processes depositing sediments