The Anglesey lakes, Wales, UK — Changes in trophic status of three standing waters as inferred from diatom transfer functions and their implications for conservation

Bennion, H; Duigan, Catherine A.; Haworth, Elizabeth Y.; Allott, T.E.H.; Anderson, N. J.; Juggins, Steve; Monteith, Donald T.

doi:10.1002/(sici)1099-0755(199606)6:2<81::aid-aqc174>3.0.co;2-g

Cited by 18 publications

(10 citation statements)

References 31 publications

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“…Long-term nutrient records for Myall Lakes prior to 1999 are not available. Palaeo-studies of lake records are producing an increasing number of examples of sites subject to anthropogenic nutrient impacts (Schelske & Hodell, 1991;Bennion et al, 1996;Umbanhowar et al, 2003;Bennion et al, 2004) related to agricultural activities such as ploughing, dairy farming and the use of fertilizers. Such studies generally use biotic remains such as diatoms or chironomid head capsules to reconstruct nutrient levels.…”

Section: Introductionsupporting

confidence: 91%

The trophic history of Myall Lakes, New South Wales, Australia: interpretations using δ13C and δ15N of the sedimentary record

et al. 2008

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In an attempt to determine the trophic history of the Myall Lakes complex (New South Wales, Australia) d 13 C org , d 15 N and C org :N profiles were determined for bulk organic matter of two short sediment cores from Bombah Broadwater and Myall Lake. 210 Pb profiles and sediment types indicate significantly different trophic trajectories during the time periods examined. d 13 C org and C org :N indicate Bombah Broadwater has been dominated by increasing inputs of terrestrial organic material over the last century, thought to be related to watershed disturbance including agricultural activity. Primary production appears to be dominated by phytoplankton. d 15 N remained relatively stable at around 1% until the mid-1970s when there was a sharp increase to 4.7%, interpreted as an influx of sewage-derived material. These observations offer an insight into the recent trophic changes at the site. Sedimentation rates are noticeably lower in Myall Lake and the most recent sediment is a flocculent organic rich deposit overlying mineral clay. d 13 C org and C org :N values indicate a transition from plankton to macrophyte dominated primary production around 1800AD. d 15 N values become increasingly negative from approximately 1900AD. This is interpreted as being due to increasing reliance by macrophytes on nitrogen recycled from decomposing sediments driven by natural infilling and eutrophication in this basin. The contrasting sedimentation rates, sediment types and geochemical profiles suggest the different basins of this water body are subject to substantially different internal and external influences which should be considered in management decisions.

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Section: Introductionsupporting

confidence: 91%

The trophic history of Myall Lakes, New South Wales, Australia: interpretations using δ13C and δ15N of the sedimentary record

et al. 2008

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“…A calibration model based on 152 sites in North‐west Europe (Bennion, Juggins & Anderson, 1996) has been used to provide reconstructions of changes in TP concentrations over historical times in Denmark and the U.K. (e.g. Bennion & Appleby, 1999; Bennion et al ., 1996a), but applying this model to Swedish sites is problematical. The North‐west European (NWE) model presently includes only 11 Swedish sites but is otherwise based on lakes that are limnologically different to many Swedish lakes.…”

Section: Introductionmentioning

confidence: 99%

Validation of a diatom–phosphorus calibration set for Sweden

Bradshaw

Anderson

2001

Freshwater Biology

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1. A weighted averaging (WA) regression and calibration model for diatoms and total phosphorus (TP) was developed from a dataset of 45 surface‐sediment samples from Swedish lakes. Jack‐knifed error statistics were comparable with those for similar diatom–TP datasets: r2jack=0.47, root mean squared error of prediction (RMSEP)=0.24 log10μg TP L–1 and mean bias=–0.002 log10 μg TP L–1 for the simple WA model; r2jack=0.36, RMSEP=0.27 log10 μg TP L–1 and mean bias=0.017 log10 μg TP L–1 for WA with tolerance downweighting. 2. The model was used to estimate TP concentrations for the Ekoln basin of Lake Mälaren using a 210Pb‐dated sediment core record. Highly eutrophic conditions developed in the basin in the 1960s as a result of nutrient inputs from cultivated land and the city of Uppsala. A reduction in the supply of phosphorus from sewage outlets in the late 1960s resulted in less eutrophic conditions. 3. The model results indicated levels of 50–60 μg TP L–1 prior to 1900. The rapid eutrophication of the lake basin after the 1950s and the subsequent recovery were evident from the diatom data. 4. Diatom‐inferred TP (DI–TP) values were validated by comparison with monitored data for the period 1966–95. The diatom model tended to underestimate TP at high levels (> 80 μg L–1) but overestimate at lower concentrations. 5. A good agreement was observed between the trends in TP concentration and the DI–TP concentration and the timing of the maximum was well reflected by the diatom‐based reconstruction. A significant correlation (r2=0.69, P < 0.01) was found between DI–TP and measured TP at this site.

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“…ter Braak & van Dam, 1989), has become a standard technique in palaeolimnology for reconstructing past environments. Anderson, Rippey & Gibson, 1993;Bennion, 1994;Bennion, Juggins & Anderson, 1996a;Bennion et al, 1996b) from fossil diatoms deep in the sediment. This can be used to infer past lake pH (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Birks et al, 1990) and total phosphorus (TP) concentrations (e.g. Anderson, Rippey & Gibson, 1993;Bennion, 1994;Bennion, Juggins & Anderson, 1996a;Bennion et al, 1996b) from fossil diatoms deep in the sediment.…”

Section: Introductionmentioning

confidence: 99%

Temporal and geographical variation in lake trophic status in the English Lake District: evidence from (sub)fossil diatoms and aquatic macrophytes

2000

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1. A sediment core (representing 250–300 years) was taken from each of three lakes of conservation interest and contrasting trophic status in the English Lake District: Wastwater, Bassenthwaite Lake and Esthwaite Water. Lithostratigraphic analyses, radiometric dating and analysis of fossil diatoms were carried out.  2. Transfer functions, based on the diatoms, were used to reconstruct total phosphorus (TP) and, thus, eutrophication at the study lakes. In Wastwater, changes in lake pH were also reconstructed.  3. The lakes were also classified according to their present macrophyte flora, the latter being compared with previous records.  4. The fossil diatoms of Wastwater were continuously dominated by taxa typical of oligotrophic, circumneutral waters, indicating that the lake has not been enriched or acidified in the last 250 years. The aquatic macrophyte flora has probably remained unchanged since before the Industrial Revolution.  5. The diatom assemblages of both Bassenthwaite Lake and Esthwaite Water began to change in the mid‐1800s. Further change occurred from the 1960s, at the onset of a recent period of eutrophication. These two lakes have experienced continued nutrient enrichment throughout the 1970s, 80s and 90s, largely associated with increasing phosphorus inputs from sewage effluent. There is no evidence of any recovery in response to recent reductions in external nutrient loads.  6. Only in Esthwaite Water has the change in aquatic macrophytes been pronounced.  7. Palaeolimnological reconstruction is useful in determining background conditions and natural variation in lake ecosystems.

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The Anglesey lakes, Wales, UK — Changes in trophic status of three standing waters as inferred from diatom transfer functions and their implications for conservation

Cited by 18 publications

References 31 publications

The trophic history of Myall Lakes, New South Wales, Australia: interpretations using δ13C and δ15N of the sedimentary record

The trophic history of Myall Lakes, New South Wales, Australia: interpretations using δ13C and δ15N of the sedimentary record

Validation of a diatom–phosphorus calibration set for Sweden

Temporal and geographical variation in lake trophic status in the English Lake District: evidence from (sub)fossil diatoms and aquatic macrophytes

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