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A survey of cadmium and zinc concentrations in ponds supplied by Höje & Kävlinge streams and their subsequent induced bacterial tolerances

DeMarco, Jamie (2019) BIOM02 20191
Degree Projects in Biology
Popular Abstract
Heavy Metals in ponds around Skåne

A recent set of sediment assessments from the bottoms of ponds in southern Sweden determined that cadmium, zinc, and phosphorous concentrations were occurring at levels higher than normal in Kävlinge Å. Sediment from these ponds was previously proposed to be used as fertilizer on nearby agricultural land in the coming future so as to exploit its phosphorus contents. However, this could not be done until the true extent of the heavy metal presence in the region was known and to what degree their deleterious effects may have extended. However, a recurring challenge in ecotoxicology is to specifically link certain biological responses to exact changes in the environment. This is crucial for the... (More)
Heavy Metals in ponds around Skåne

A recent set of sediment assessments from the bottoms of ponds in southern Sweden determined that cadmium, zinc, and phosphorous concentrations were occurring at levels higher than normal in Kävlinge Å. Sediment from these ponds was previously proposed to be used as fertilizer on nearby agricultural land in the coming future so as to exploit its phosphorus contents. However, this could not be done until the true extent of the heavy metal presence in the region was known and to what degree their deleterious effects may have extended. However, a recurring challenge in ecotoxicology is to specifically link certain biological responses to exact changes in the environment. This is crucial for the establishment of legislation for environmental pollution levels and of interest in areas that contamination is newly found, such as these ponds.

One means of determining that organisms have been affected by a specific pollutant is by seeing if the bacterial communities have developed an increased resistance to an environmental pollutant. Similar to how bacteria can develop a resistance to antibiotics, bacteria can also develop a resistance to many other pollutants as well. These tolerances thereby unambiguously support that the pollutant has had an environmental impact that is of interest. This concept has been repeatedly applied to heavy metals in various environments and it was therefore suspected that the bacteria in ponds surrounding Kävlinge Å had developed a resistance to both cadmium and zinc. My project ultimately aimed to understand the tolerance that the bacterial community could have develop toward Cd and Zn and was executed by addressing the following questions:

(1) What were local heavy metal concentrations?
(2) To what extent did local concentrations affect bacterial tolerance?
(3) At what levels of Cd and Zn could a tolerance be induced and when did this occur?

Conclusions
After sending samples to a support laboratory, Cd and Zn concentrations in the sediment samples in all of the ponds were to determined to fall below regulatory guidelines in Sweden. Additionally, no previously induced tolerance could be detected from growth rate analysis after re-exposure of the bacteria to the heavy metals again. However, it is likely that a tolerance to Cd can be induced if concentrations increased to a range of 0.52-3.70 mM Cd/g sediment. My findings ultimately support that no resistance has developed in the studied ponds and that the local municipalities should further explore these sediments as a viable and local means of attaining phosphorus.


Master’s Degree Project in Biology, 30hp
Department of Biology, Lund University

Advisor: Johannes Rousk (Microbial Ecology) johannes.rousk@biol.lu.se
Secondary Advisor: Jonas Johansson (Höje Å och Kävlingeån Vattenråd) jonas.johansson@lund.se (Less)
Please use this url to cite or link to this publication:
author
DeMarco, Jamie
supervisor
organization
course
BIOM02 20191
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8997001
date added to LUP
2019-10-23 10:46:32
date last changed
2019-10-23 10:46:32
@misc{8997001,
  author       = {DeMarco, Jamie},
  language     = {eng},
  note         = {Student Paper},
  title        = {A survey of cadmium and zinc concentrations in ponds supplied by Höje & Kävlinge streams and their subsequent induced bacterial tolerances},
  year         = {2019},
}