Effects of eutrophication pdf

Bricker, Suzanne B. Suzanne Boyd ;. Corporate Authors:. Content Notes:. Suzanne B. Document Type:. Miscellaneous ;. Place as Subject:. United States ;. Rights Information:. Main Document Checksum:. File Type:.

Supporting Files. Center for Coastal Monitoring and Assessment U. Published Date:. Results tarsus sp. Habitat characteristics and seasonal eutrophication Average abundance and biomasses of macroinvertebrates phenomena varied between sampling occasions within years Table 1. Maximum abundance of macroinvertebrates was recorded at The study area is characterized as eutrophic with summer from late June to July. It reached 23,—51, ind. Maximum total biomass Chironomidae contributed from Daytime dissolved oxygen In amphipods observation period.

Temporary droppings in oxygen concen- were most abundant 3. In both next years biomass proportion of amphipods every year Fig. Oligochaetes were abundant in and bottom water were recorded during several days and even , when their contribution in total biomass reached 20 weeks, when dissolved oxygen content varied between 5. The oxygen drops coincided with total biomass with a maximum in The mollusks mainly the periods of the highest phosphates concentration in water Gastropoda were common taxa but not dominant in terms Fig.

The negative relationship between oxygen and total of biomass 2—2. Invertebrate community composition, abundance and 3. The oligochaetes Stylaria lacustris L , Limnodrilus dates Fig. The abundance of oligochaetes and total abundance Reiss et Fittkau, Paratanytarsus quintuplex Kieffer, Rheotany- increased with a decrease in total phosphorus, but these Fig.

Mean biomass contribution of macroinvertebrate taxa mean for season at study site: 1-Chironomids, 2-Amphipods, 3-Hirudineans, 4-Oligochaetes, 5-Ephemeropterans, 6-Mollusks, 7-Trichopterans, 8-Others. S84 N. Other major internal sources of nutrients are 4.

The decomposition macroinvertebrates coincided with the periods of oxygen of C. Severe impacts of algae inter-algal waters and bottom habitats. Deterioration in decomposition on macrofauna abundance were recorded in a quality of benthic habitats oxygen depletion in the water lot of eutrophied estuaries and lagoons Norkko and Bons- column and in the sediments as a result of excessive growth dorff, ; Bona, The decline in abundance of up to 4.

Among Also, algae decomposition process often may accompany by a invertebrates, the chironomids, amphipods and hirudineans release of toxic hydrogen sulphide in bottom habitats Lavery and were the dominating taxa in coastal zone of Neva estuary McComb, The decomposition of the drifting algal mats with temporal oxygen depletions.

These processes provide an over short period after oxygen condition improvement. This additional supply of inorganic compounds to be potentially life strategy of chironomids may explain their dominance available for recycling of the compounds in the water. It may be a result of rapid phosphorus release pietra et al.

The survival amphipods may during algae decomposition. Phosphorus released of C. The biomass of the by narrow zone of shallow littoral to 20 m distance of algae drift in the Neva Estuary reached 1 kg m-2 in dry weight shoreline , e.

At this high biomass the phosphorus In the other areas of Methods for chemical analysis of freshwaters, IBP Handbook, 8. In the Archipelago Sea areas covered by decaying Sea Environ. Also, the algal mats Hodgkin, E. No simple solution: proposing radical manage- ment options for a eutrophic estuary. Oceanologia 47 S2 , — Fisheries Manag. Hydro- in structure and dynamics of invertebrate communities. Lavery, P. However, the study did indicate that a period, regulatory agencies may prefer to consider other assess- greater amount of treatment resources would be necessary to ment options that would not immediately result in water quality disinfect and coagulate water with greater chl-a, which agrees violations for Beaver Lake.

Each of these ST standards apply to a growing season geometric mean and an considerations are first based on the fact that the standards were annual arithmetic average, respectively, at the Hickory Creek effectively equivalent to a long-term expected average condi- location in Beaver Lake. The standard values were based on a tion in Beaver Lake at Hickory Creek. Further, to our knowl- weight-of-evidence approach, but the location to which they edge no drinking water standards were violated in periods when were applied in Beaver Lake was effectively equivalent to the our hindcasts indicated that Beaver Lake may not have been in expected long-term average conditions.

Thus, another possible compliance with in-lake water quality standards at the Hickory consideration for assessment is moving the location against which Creek location.

Thus, these options also offer possibilities for the criteria are evaluated. The probability-of-exceedance analysis decreasing the risk of exceeding the criteria based on how the presented in this study could be used to inform regulatory agen- growing season geometric mean chl-a and annual average ST cies and stakeholders on the number of exceedances allowed with data are assessed.

However, we have dem- to the standard and subsequent approval by the state legislature. Indeed our analysis is The probability analyses used to derive assessment meth- supported by the fact that four of six growing season geometric odologies in this project require relatively long-term data and mean chl-a and three of six annual average ST values measured assume no directional change during the period of record.

It is at the Hickory Creek location in Beaver Lake exceeded the water important to note that both of these requirements had to be quality standards. Multiple studies have indicated that decadal- stretched to complete the analysis. For example, long-term data scale trends in chl-a in lakes may be related to climatic variability were not available for the Hickory Creek location, so a model- Arhonditsis et al. Assuming that ing approach based on the original standard development FTN Beaver Lake conforms to a similar pattern, the use of a longer Associates, was used to calculate the exceedance prob- assessment period that approaches or exceeds a decade in length abilities for this site.

Further, there was a long-term trend in the 9 or 11 yr may capture the full range of potential chl-a variation growing season geometric mean chl-a and annual average ST at due to climate variability.

No trends were apparent at the other moni- Regulatory agencies could also consider using a rolling or toring locations. However, too few data were available to assess moving average of the yearly geometric mean chl-a during the this trend at Hickory Creek. What remains agement, or anthropogenic factors. Moreover, the probabilities that approximately half of based variability Arhonditsis et al.

For the purposes of this project, we simply acknowledge high with this approach. We also put Couple the Standards more weight on data collected before when the water qual- The chl-a and ST were probably intended to be considered ity standards were adopted. The growing season As a result, the standard developers used a regression relation- geometric mean chl-a concentration and annual average ST at ship between measured values at the Highway and Lowell Hickory Creek are strongly related because the chl-a concentra- locations for both chl-a and ST to derive estimates for these tion largely controls ST Carlson, Thus, another option parameters at Hickory Creek.

Because standard development relied standards are violated in more than half of the years in which the on a regression equation with poor predictive power, the exceed- lake is assessed.

This assessment method would provide the most ance probabilities calculated using these data could be unreliable. Welch, S. Peterson, and S. Restoration and management of lakes and reservoirs. The phosphorus—chlorophyll relationship in sonably realistic.

Nevertheless, the chl-a and ST standards for lakes. Beaver Lake site-specific water quality criteria yr are available. FTN no. FTN Assoc. Downing, R. Cruse, and P. Effects of or more due to water quality management at the watershed scale watershed configuration and composition on downstream lake water Scott et al. Although the Lowell location was the only quality.

Barfield, and J. Design hydrology and sedimentology for small catchments. Academic Press, San Diego. Water quality standards: Designated uses these variables and time at the other locations may suggest a and numeric criteria development. In: Y. Li and K. Migliaccio, editors, weak trend.

Thus, a more detailed examination of the trends is Water quality concepts, sampling, and analysis. Moore, S. Katz, B. Dennis, and E. Nevertheless, our analysis demonstrates that while the Silow. Global Change Biol.

Sharpley, P. Withers, J. Scott, B. Haggard, and C. Phosphorus mitigation to control river eutrophication: Murky recent years. Lind, and L. Reservoir primary production.

In: K. Thornton et al. Study Implications Lind, O. Terrell, and B. Problems in reservoir trophic- state classification and implications for reservoir management. In: M. The results of this study demonstrate the importance of link- Straskraba et al. Kluwer Acad. These considerations should 57— Mash, C. Winston, D. Meints, A. Pifer, J. Scott, W. Zhang, and occur before standard development to ensure that promul- J. Assessing tricholormethane formation and control in gated standards are compatible with the assessment period and algal-stimulated waters amended with nitrogen and phosphorus.

Our study dem- Sci. Haggard, A. Sharpley, and J. Change point analysis of phosphorus trends in the Illinois River Oklahoma criteria and effects-based numeric criteria for nutrients because demonstrates the effects of watershed management. In fact, nutrient concentrations, chl-a, and ST in lakes Scott, J. McCarthy, T. Otten, M. Steffon, B. Baker, E. Grantz, et al. Comment: An alternative interpretation of the relationship can exhibit tremendous interannual variation due to annual between TP:TN and microcystins in Canadian lakes.

Unlike toxic substances or Sci.