DEPARTMENT OF MARINE SCIENCES

Degree project for Bachelor of Science with a major in Marine Sciences

[MAR304, Bachelor degree project in marine science, major in marine geology, 15 hec]

First Cycle

Semester/year: Spring 2017

Supervisor: Kjell Nordberg, Department of Marine Sciences

Examiner: Katarina Abrahamsson, Department of Marine Sciences

HEAVY METAL CONCENTRATIONS IN THE

SANNÄS FJORD INNERMOST PART

Landfill contamination and environmental status in the Sannäs fjord surface sediments

Amelie Sjösten

1

Abstract

The aim of this study is to examine if nearby closed landfills affect the Sannäs fjord

sediments, but also an examination over the whole fjords environmental status with the help

of transects taken in 2016. There is a general perception amongst the locals that two, now

closed landfills leaks contaminants into the fjord and its sediments. The Sannäs fjord is a

pristine fjord located on the Swedish west coast without industry and commercial harbors,

yet the fjord is under environmental pressure with its heavy metal concentrations. Leisure

boat activities in combination with the fjords hydrography and characteristics as an estuary,

contribute with accumulation of heavy metals in the sediments.

Within this study surface sediment samples and some occasional stratigraphic

samples were taken on 14 stations, spread over the area on both land and in the fjord. The

samples were analyzed according to the Swedish standard with the help of ICP-MS and

isotope-ratio mass spectrometer analyzes. By analyzing concentrations of the elements:

arsenic, cadmium, chromium, copper, nickel, cobalt, zinc, mercury and lead, and also carbon

and nitrogen, an environmental classification according to Swedish guidelines could be

made together with a discussion of possible pollution sources including the landfills possible

leakage. The heavy metal concentrations did not show any alarming values, which means

no concentration is above class 3 of the Swedish Environmental Protection Agency

environmental classification, indicating a relatively clean fjord. Results from the analyzes

shows a slight decrease of lead and mercury concentrations since 2008, but also a slight

increase of arsenic-, copper- and zinc concentrations throughout the fjord that indicate

continued environmental pressure.

Agriculture have a greater impact at the innermost part of the fjord, which is noticeable

when looking at the elevated cadmium and nitrogen values, also further down in the

sediments. The stream Skärboälven have a great impact on the innermost part since it is the

main freshwater inflow to the fjord, including a larger agriculture area that contribute with

nitrogen and phosphor to the fjord. There is also a high supply of carbon and nitrogen from

land at the innermost parts and another possibility is that nearby grazing birds and cattle

may affect the nitrogen values. Heavy metal concentrations, carbon and nitrogen further

down in the sediment also indicate a more polluted environment and reflect the general

regional contamination signal in the fjord, which is also found in previous cores. The

concentrations downcore could also depend on the previous agriculture, landfills leachate,

point sources (e.g. pier) and the natural fast degradation of nitrogen leaving behind more

carbon downcore.

It is still uncertain if the older sediment further down was affected by leachates from

the landfills, but the surface sediments of today is most likely not affected by the closed

landfills because of the general low concentrations, the distance to the fjord and the previous

risk assessment by the County Administrative board. The Sannäs fjord is still a pressured

yet clean fjord, where pollutions may come from leisure boat activities and agriculture from

the stream Skärboälven.

Key words: Sannäs fjord, landfill, surface sediment, heavy metal contamination,

environmental changes.

2

Sammanfattning

Syftet med denna studie är att undersöka ifall nedlagda deponier påverkar

Sannäsfjordens sediment, samt att undersöka miljöstatusen utöver hela fjorden med hjälp av

transekt tagna från 2016. Det finns en allmän uppfattning bland befolkningen i området om

att två nedlagda deponier läcker föroreningar till fjorden och dess sediment.

Sannäsfjorden är en fjord på svenska västkusten utan industri och stora hamnar, men

ändå är fjorden belastad av tungmetaller. Fritidsbåtsverksamheten i kombination med

fjordens hydrografi och egenskaper som estuarium har bidragit med ackumulering av

tungmetaller i sedimentet.

Inom föreliggande studie togs sedimentytprover samt några enstaka stratigrafiska

prover från 14 stationer utspridda i området både på land och i fjorden. Dessa analyserades

enligt svensk standard med hjälp av ICP-MS och isotope-ratio mass spectrometer analyser.

Genom att analysera koncentrationer av elementen: arsenik, kadmium, krom, koppar, nickel,

kobolt, zink, kvicksilver och bly samt kol och kväve, kunde en miljöklassning enligt svenska

riktlinjer utföras och en diskussion om troliga föroreningskällor samt deponiernas spridning

möjliggjordes. Koncentrationerna av tungmetallerna visade inte några alarmerande halter

vilket innebar att de inte översteg klass 3 i Naturvårdsverkets miljöbelastningsklassifikation,

vilket i sig antyder att fjorden fortfarande är relativt ren. Analyserna visar att

koncentrationerna av bly och kvicksilver hade minskat sedan 2008. Däremot fanns en svag

ökning i arsenik-, koppar- och zinkkoncentrationerna utmed fjorden, vilket tyder på fortsatt

miljöbelastning. Jordbruket har en större påverkan i de innersta delarna av fjorden, vilket

syns på de förhöjda kadmium och kväve-halterna, så även längre ner i sedimenten.

Skärboälven har en stor påverkan på de innersta delarna då det är det största inflödet i

fjorden. I det stora avrinningsområdet med omkringliggande jordbruk på cirka 43 km2 är 51

% av kvävet antropogent (där en stor andel kommer från just jordbruket). Det finns även en

möjlighet i att fåglar samt boskap i området påverkar kvävehalterna och en stor tillförsel av

kol och kväve in i fjorden från land.

Om de äldre sedimenten längre ner är påverkade av deponierna är fortfarande oklart.

Ytsedimentet är med stor trolighet ej påverkat av de nedlagda deponierna i dagsläget, med

tanke på de generellt låga halterna, avståndet och tidigare riskbedömning av länsstyrelsen.

Sedimentet längre ner med högre halter kan spegla den allmänna regionala

belastningssignalen över fjorden, då stratigrafier på tidigare tagna stationer i fjorden och på

andra platser i regionen har liknande tungmetall koncentrationer neråt i lagerföljderna.

Stratigrafierna antyder också en påtaglig terrester påverkan då en hög kol/kväve-kvot

påträffas längre ner i sedimentet i fjordens innersta delar. Men halterna kan också bero på

det tidigare jordbruket, Olseröds lakvatten, punktkällor, alger och den naturligt snabbare

nedbrytningen av kväve som lämnar kvar mer kol. Allt detta i kombination med fjordens

hydrografiska processer. Sannäsfjorden är fortfarande en belastad men relativt ren fjord, där

föroreningarna i fjorden kommer till största delen från fritidsbåtsverksamhet och jordbruk från

Skärboälven. Deponier påverkar troligen inte sedimenten i nuläget, och det är oklart om de

gjorde det när de fortfarande var aktiva.

Nyckelord: Sannäsfjorden, deponier, marina sediment, tungmetall föroreningar,

miljöförändringar, lakvatten.

3

Table of Contents

Abstract ................................................................................................................................................... 1

Sammanfattning ...................................................................................................................................... 2

Introduction ............................................................................................................................................ 4

1.1 Study Area ..................................................................................................................................... 4

1.2 Hydrography ................................................................................................................................. 4

1.3 Heavy Metals and Potential Pollution Sources ............................................................................. 6

1.4 Previous Studies ............................................................................................................................ 8

2 Material and Methods ......................................................................................................................... 8

2.1 Sampling and Subsampling ........................................................................................................... 8

2.2 Sediment chemical analyses ......................................................................................................... 9

2.2.1 Heavy metal analysis .............................................................................................................. 9

2.2.3 Normalization ......................................................................................................................... 9

2.3 Environmental Classification ......................................................................................................... 9

3 Results ................................................................................................................................................ 10

3.1 Environmental status .................................................................................................................. 10

3.2 Heavy Metals: ............................................................................................................................. 10

3.2.1 Surface Sediments................................................................................................................ 11

3.2.2 Normalized Samples and Stratigraphy ................................................................................. 12

3.3 Carbon and Nitrogen:.................................................................................................................. 20

4 Discussion ........................................................................................................................................... 21

5 Conclusion .......................................................................................................................................... 25

6 Acknowledgment ............................................................................................................................... 26

7 References ......................................................................................................................................... 26

Appendix A ............................................................................................................................................ 30

Appendix B ............................................................................................................................................ 31

Appendix C ............................................................................................................................................ 32

4

Introduction

The Sannäs fjord is located in a scenic area on the Swedish west coast and is a part of

the NATURA-2000 directive. The fjord lacks industries and has previously been known for its

rich fishery, which subsided 1985, as well as for its rich oyster and mussel banks. Even

though there is a lack of industries and significant sewages, the environmental quality of the

fjord has declined over the last 30 years (Nordberg et al., 2012, 2017 and personal

communication 2017).

There is and has been general concern in the area that closed old landfills have been

contributing pollutants into the fjord. The aim of this study is to investigate if the landfills

affect the recent surface sediments and if they had an impact in the past. This is a

complementing study to Nordberg et al (2012) previous work, here focusing on the

innermost part of the Sannäsfjord. This work covers the heavy metal concentration, carbon

and nitrogen in the surface-sediments of the innermost part of the fjord. Ditches that are

connected to the closed and abandoned landfills have also been sampled in the study. But in

addition, the study is also an overview study of the environmental status of the fjords surface

sediments by looking at heavy metal concentrations as well as carbon and nitrogen along

the entire fjord by using new results from sediment samples taken in august 2016 (Nordberg

et al., unpublished data).

1.1 Study Area

The Sannäsfjord is a sill fjord located south of Strömstad on the Swedish west coast

with a surface area of 4 km2 (EEA, 2017). From its opening in the NW, the fjord extends

inland towards the SE. Grebbestad and Sannäs are the closest communities that affect the

fjord (Fig. 1 - 2).

The fjord consists of two deep-basins with associated sills: Saltpannan and

Västbacken, which connect by two narrow straits. The fjord is deeply influenced by

Skagerrak from the outside. Saltpannans deep-basin reaches a maximum depth of 32 m and

the sill 8m (Nordberg et al, 2012 & Robijn 2012). In this study, the main focus will be on the

innermost part of the fjord where the depth varies from 0.3 to 5 m. Transects from another

study over the whole fjord will also be included (Nordberg et al., unpublished data) to cover

the whole fjords surface concentrations. The crystalline bedrock characterized by the young

Bohus granite surrounds the fjord. The sediments consist of gravel, sand and silt near the

sills, with sediments of silty clay and clays in the deeper parts of the fjord. The innermost

inclined part mainly consists of silty, gyttja clays and organic-rich gyttja clays and clay

gyttjas. The innermost parts have a high organic content due to the biogenic content of the

fjord, nutrient inflow and inflow from terrestrial material (Robijn, 2012)

1.2 Hydrography

The largest influences of water exchange and currents on the fjord are the estuarine

circulation, with the inflowing saline water from Skagerrak and the outflowing brackish

surface water. The large scale oceanographic patterns are influenced by the North Sea

water transported by the Jutland current to Skagerrak and Kattegat. The high saline waters

5

from the Jutland current mixes with the low saline waters from the Baltic current (20 psu)

near Marstrand, transporting the mixed water north to later unite with the Norwegian current.

Inside of the Sannäs fjord there is three different water masses: a deepwater layer

around 33 psu made up by Skagerrak water. An intermediate layer also consisting of

inflowing Skagerrak water, reaching down to sill depth at 8 m and an outflowing brackish

surface layer reaching down 1 m, influenced by freshwater from streams and run-offs

(Nordberg et al, 2012 & Ödalen,2012). There is also a horizontal current pattern in the

surface water transporting in Skagerraks surface waters via the west side of the fjord,

circulating back up at the east side of the fjord. A deepwater exchange below sill depth takes

place around 5 times a year due to wind patterns forcing water from Skagerrak into the fjord.

The intermediate water layer exchanges around every 6th to 20th day. The innermost parts of

the fjord are mostly affected by the surface and intermediate water layers because of its

depth, and also the freshwater stream Skärboälven. The intermediate water layer salinity

varies between 18-30 psu depending on the freshwater input and winds, making it possible

for mussels and oysters to inhabit the innermost parts (Swedish Agency for marine and

water management, 2017). The sometime high salinity at the innermost part is also possible

due to upwelling in the innermost area (Nordberg, personal communication).

Accumulation rates to the sediments and water depth from Nordberg et al (2012), will

be presented in Appendix B at closely located stations.

6

Figure 1&2: (1) Map that includes sampling stations and agriculture areas surrounding

the southern part of the Sannäsfjord, and a location map over the entire fjord. Data taken at

1-2 April 2017 and disposal areas represents the station closest to the landfills. (2) Includes

stations over the whole Sannäs fjord, including (Nordberg, unpublished data) sampled in

august 2016 and an inserted map showing the Skagerrak and Kattegat region.

1.3 Heavy Metals and Potential Pollution Sources

A majority of the fjords at the Swedish west coast show an anthropogenic print by

elevated heavy metal concentrations in the sediments (Pizarro, 2015). Contamination

sources such as agriculture, sewage, industries, harbor and boat activities leave a fingerprint

in the sediment. Heavy metals attract and adsorbs to the clay-silt particles or organic

materials since these have the optimum adsorption capacity (Pizarro, 2015). Also,

depending on exchangeable cations and carbon content, higher total organic carbon content

may result in a larger adsorption of metals (Nordberg et al ,2012).

Previous publications on concentrations of pollutants found in the sediment of the

Sannäsfjord, have been of great interest and surprising, since the fjord does not have any

industries or commercial harbors. Most of the contaminants come from the outside or from

inflows, leisure boat-activities and agriculture (Nordberg et al, 2012 & Robijn, 2012). The

fjords contamination levels are affected by the geo-chemical and hydrographic properties of

the fjord as well as its quality as an estuary. The influences from the outside depend on how

the water flows or exchange in the fjord, and its morphology and bathymetry as an estuary

(Pizarro, 2015). Nordberg et al (2012) correlate the heavy metal concentrations, together

with organic pollutants, with the harbor and boat-activities in the fjord but also impact from a

nearby golf-course and Sannäs, in combination with the agricultures nutrient flow (Ödalen,

2012).

Agriculture areas are closely connected to the fjords shore, ditches and the stream

Skärboälven (Fig. 1). Artificial phosphate fertilizers affect the concentration of cadmium and

zinc in many fjords at the west coast (Berndes et al, 2004), but fertilizers and cattle also

contribute to higher nutrient levels in coastal waters, especially nitrogen (Bergsbäck et al,

1994). The Skärboälven catchment area is 43 km2 and the stream discharge around 0,5-1

m3/s of fresh water (Ödalen, 2012). Around 51 % of the nitrogen in the stream comes from

anthropogenic sources, mainly agriculture and surrounding woodland (County Administrative

board, 2017). The area is also a part of the Natura 2000 directive including a bird-habitat

with geese, swans, ducks and wading bird populations (EEA, 2017 & County Administrative

Board of West of Götaland, 2017) that may contribute and enhance the nitrogen values in

the fjord (Ruess et al, 1989 & Olson et al, 2005).

Landfills:

The landfills Olseröd and Falkeröd have been closed since 1974 and 1960

respectively and have ditches connected to the Sannäsfjord (Fig. 1&2) which could have

been subjected to leachates. A laundry also had its drain through the Skärboälven up until

the mid-1970s, when the outlet was redirected to the cleaning plant in Grebbestad.

The connecting ditches have no calculated inflow, but it would presumably be very low

since the clay-silt fraction found in the ditches indicates accumulation. Landfills started to be

7

considered an environmental problem in the 1970s, restrictions came around the same time

resulting in better care of leachates. All closed landfills are still under supervision by the

county and municipality (Rambo AB, 2008). The previous landfills in this study have been

examined and classified by the county administration board (MIFO) on how much of a risk

they are for the surroundings (Environmental Cooperation, West of Götaland, 2010, SEPA

1999 and Web-GIS 2010). Certain criterias must be reached for different classes in the risk-

analysis. Categories such as distribution possibilities, sensitivity, protection value,

contamination levels and how toxic the pollution are, are all parts of determining the risk the

landfill and leachate have on the environment (SEPA 1999 & 2008). The two landfills

Olseröd and Falkeröd are classified in the third risk-category, making them relatively

unharmful to their surroundings on the 1 to 4 risk-scale (Web-GIS, 2010 & Tanum Township,

2006). Open leachate ditches have been used by old landfills to drain the ground from

accumulating pollutants and preventing them from contaminating the ground water. Leakage

in the ground could lead to bioaccumulation and harm for surrounding ecosystems. Leachate

ditches is supposed to handle flooding, high water flows and high precipitation, and are

included in the risk analysis (Environmental Cooperation West of Götaland, 2010).

At the landfills, mainly domestic waste and industrial waste was dumped (Rambo AB,

2008). Common domestic waste includes car parts, batteries, plastic waste, paint and

electronical equipment (Environmental Cooperation West of Götaland, 2010).

Heavy Metals:

Most metals, such as zinc, arsenic and cobalt are essential as nutrients for organism,

but in high concentrations they become an environmental risk due to their toxicity (Mason,

1995). The metals do not degrade, they accumulate and bioaccumulate in the sediments or

get transported away as suspension load with for e.g. the current systems in the fjord.

Anthropogenic sources of heavy metals include paint, anti-fouling paint and pesticides for

arsenic and copper. Zinc can be found in anti-fouling paints, zinc-anodes and batteries.

Cadmium and lead have the ability to replace zinc in molecules, making them inactive and

toxic (Nordberg et al, 2012). Zinc can also be found in arable soils in agriculture (Bengtson

et al, 2005). Mercury is found in waste from older industrial products such as thermometers

and mercury pickled grains from agriculture before 1966 (SIME, 2010).

Cadmium is also found in older plastic products, batteries and paints (Nordberg et al,

2012), but a ban in 1982 stopped the use of cadmium in industrial products. Recent studies

have shown that the diatom Thalassiosira use cadmium as a nutrient-supplement when zinc

is low (Lane et al, 2005, Lane & Morel, 2000). It is possible that they absorb and bio-

accumulate cadmium that later enrich in the sediments. The diatom flora in the Sannäs fjord

is poorly studied, but studies on diatoms in Gullmarsfjorden and Koljöfjorden may suggest

that a similar flora can be found in the Sannäs fjord due to the same influence from Kattegat

and Skagerrak (McQuoid 2002, McQuiod 2005 and McQuoid and Nordberg 2003).

Carbon isotopes and carbon/nitrogen can trace the source of the content, where higher

values of carbon can be found in terrestrial material and higher nitrogen values can be found

in marine environments (Nordberg et al, 2012).

8

1.4 Previous Studies

Previous studies on distribution and contamination of heavy metals in coastal

sediments in Bohuslän have been published by the Swedish Geological Survey e.g. Cato

1992, 1997, 2006 and by Apler & Josefsson 2016. Studies in fjords and estuaries have been

performed by e.g. Cato 2004, Nordberg et al (2012); Brattström et al., (2015); Gomes et al

(2015) and Pizarro (2015). The studies on Sannäsfjorden and has been ongoing since 2006,

Andersson 2006; Olsson 2007; Ödalen 2012; Robijn 2012; Polovodova et al, 2015;

Nordberg et al 2017. The reports and papers from the Sannäsfjord include a wide

perspective on pollutants, hydrography and foraminiferal distribution. Stratigraphic studies

have been made by Robijn (2012), covering age-models, forams and heavy metal

concentrations. Recent studies of the fjord cover oxygen depletion and foraminiferal fauna in

the shallow area of the fjord (Nordberg et al, 2017). Ödalen (2012) analyzed the oxygen

deficiencies related to hydrography.

2 Material and Methods

2.1 Sampling and Subsampling

Samples were taken on 14 different stations during the 1-2 April 2017 in the

Sannäsfjord and near adjacent closed landfills with connecting ditches (Fig. 1&2),

geographical positions are presented in table 1. Sediment cores from stations 8 to 14 were

taken from a boat with a Kajak Core Sampler. An extruder was used to subsample the top 2

centimeters of the cores. From the stations 9,10,11 and 13, samples 10-12 cm and 20-22 cm

(only 9 and 11) down the cores were also collected. All samples were put in polyethylene

containers. On stations 1 to 7, only a plastic spoon and the polyethylene containers was

used to gather the uppermost 2 cm of sediments.

Core-samples from august 2016 were taken with a Gemini corer and an extruder was

used for subsampling the surface sediments (0-2 cm).

Table 1: Station, date, time, coordinates and water depth for the sediment samples taken

2017.

Station-ID Date Time land/fjord Long (WGS 84) Lat (WGS 84) Water depth [m]

1 01-apr 13:21 land E 11° 15,622 N 58° 41,754

2 01-apr 13:23 land E 11° 15,624 N 58° 41,746

3 01-apr 13:43 land E 11° 15,3 N 58° 42,908

4 01-apr 13:46 land E 11° 15,334 N 58° 42,892

5 01-apr 14:02 land E 11° 16,544 N 58° 43,208

6 01-apr 14:13 land E 11° 15,895 N 58° 43,14

7 01-apr 14:15 land E 11° 15,944 N 58° 43,122

8 02-apr 11:44 fjord E 11° 15,283 N 58° 42,984 1

9 02-apr 11:53 fjord E 11° 15,248 N 58° 42,984 0,5

10 02-apr 12:05 fjord E 11° 15,49 N 58° 43,176 0,5

11 02-apr 12:11 fjord E 11° 15,425 N 58° 43,143 0,6

12 02-apr 12:19 fjord E 11° 15,164 N 58° 43,165 3,6

13 02-apr 12:31 fjord E 11° 15,292 N 58° 43,335 0,5

14 02-apr 12:38 fjord E 11° 15,151 N 58° 43,239 4,7

9

2.2 Sediment chemical analyses

All the samples were freeze-dried before further analysis. Two grams of each sample

were homogenized in an agate-mortar before more precise weighing.

2.2.1 Heavy metal analysis

The heavy metal analysis was made according to the Swedish standard method

(SS028183), commonly used in Swedish environmental studies (SEPA, 2000). One gram of

the homogenized sediments was added to 20 mL of 7 M HNO3 and then boiled in an

autoclave at 120 degrees Celsius for 30 minutes. This method leach out the metals from the

sediment. After letting the samples set, 1 mL of the supernatant was diluted with 24 mL of

Aqua Regia (0.79 % HNO3, 0.69% HCl). Samples was analyzed in an Agilent 8800 ICP-MS

(Inductively Coupled Plasma Mass Spectrometer) performed at the department of Earth

science, University of Gothenburg, and thereafter re-calculated and presented in mg/kg dw

in table 3. Concentrations from August 2016 sampled from Nordberg et al., unpublished

data, presented in table 4 and other information in Appendix B.

2.2.2 Carbon and Nitrogen analysis

Between 15-30 grams of the homogenized sediment samples was weighted in to silver

capsules. The open capsules were then placed in a desiccator together with concentrated

HCl (acidic vapor) for 48 hours to dissolve any inorganic carbon such as calcium carbonates

(CaCO3). After that the samples was left to dry in an oven at 60 degrees Celsius for 1 hour,

to get rid of any access acid. The silver capsules were placed in tin capsules and then

sealed for analyses in a GSL elemental analyzer coupled to an isotope-ratio mass

spectrometer (20-22, Sercon Ltd., Crewe UK). Analyses were performed at the department

of Earth Science, University of Gothenburg. Data-values presented in Appendix C.

2.2.3 Normalization

By normalizing the heavy metal concentration with the total organic carbon (TOC)

(mg/kg OC) a comparison between areas with different carbon content can be made, for e.g.

a comparison between the fjord and the landfills. All values are presented in Appendix C.

2.3 Environmental Classification

By working according to the Swedish standard method, a comparison to reference-

values from the Swedish Environmental Protection Agency (SEPA, 2000) can be used for

classification. The reference values are based on statistical analyses for pre-industrial values

and there are five categories based on the deviation from that reference value (table 2). This

classification method is used due to previous studies classification in the area, for a better

comparison. Another commonly used classification is the Norwegian classification system,

which would be a more useful alternative for ecotoxicological purposes.

Table 2: Classification-values for Heavy metal concentrations in sediments, based on

deviation from reference-values provided by SEPA (2000).

10

3 Results

3.1 Environmental status

The fjord sediment samples have a greenish grey to dark grey color with a weak sulfur

scent. Mixing due to bioturbation occurs in a majority of the fjord sediments, especially for

station 9. Scattered mussels (Mytilus edulis), oysters (Ostrea edulis, Crassostrea gigas) and

frequently occurring Crepidula fornicate were also noticed in the inner fjord area. Station 5

sediments differed from the other consisting of a rust influenced color and coarser grains.

Biogenic material was found in a majority of the samples. The marine sediments mainly

consist of gyttja clay and silty gyttja-clay with a large amount of biogenic content. Stations 1

and 2 are located in an alder fen.

3.2 Heavy Metals:

The higher the concentration the larger the deviation from the reference value (Table

2).Table 3 and 4 shows the values and classification of each heavy metals concentration

from April 2017 and August 2016. In table 3, arsenic, chrome, copper, nickel, cobalt and lead

concentrations belong to class 1 & class 2. Cadmium, Zinc and Mercury all have

concentrations of class 3, but mercury also show very low concentrations, undetected

(shown as n.d. in table 3) concentrations below zero in the raw data from the ICP-MS.

Cadmium has one station (sample from station 9 on a sediment depth of 20-22 cm) in class

4. All heavy metal concentrations in Table 4 do not have a higher classification than class 3.

Nickel, cobalt, lead, cadmium and chrome classify between class 1 and class 2 and the

arsenic, zinc, copper and mercury values match class 3 on certain stations (table 4).

11

Table 3: Shows the environmental classification and concentrations of the surface sediments

from1-2 April 2017. Undetected values are shown as n.d. (no data received from the ICP-MS

during analysis).

Table 4: Shows environmental classification and concentrations of the surface sediments of

samples taken in 15 August 2016 (Nordberg et al., unpublished data).

3.2.1 Surface Sediments

Arsenic (As), shows the highest concentrations at section 3 and the west station in section 1

in class 3. The lowest concentrations can be found at station “Malin” and the stations located

on land. Station 12, Bur 1 syd, Section 1 (East and middle) and section 2 (East and middle)

all belongs to class 2 (Fig. 5).

Cadmium (Cd), shows class 3 concentrations on the stations 1, 6 (land), 12 and 14 (fjord).

The innermost part of the fjord has generally higher values than the rest of the Sannäs fjord

(near section 1) were they classify in class 1 (stations Malin, section 3 (East station) and

section 2 (west station)). The metal with the highest classification of all samples (from 2017

(station 1-14)) is cadmium (Fig. 4 & Table 3).

Stations Land/ Marine Centimeters Unit Arsenic Cadmium Chromium Copper Nickel Zinc Cobalt Mercury Lead

samples [cm] As Cd Cr Cu Ni Zn Co Hg Pb

1 Land 0-2 [mg/kg dw] 1,66 0,70 7,43 19,43 9,40 59,46 3,32 0,07 12,00

2 Land 0-2 [mg/kg dw] 1,52 0,26 7,28 7,31 4,25 42,09 1,66 0,04 9,31

3 Land 0-2 [mg/kg dw] 4,46 0,37 11,44 11,58 9,33 69,62 4,82 0,02 5,64

4 Land 0-2 [mg/kg dw] 2,09 0,23 6,63 5,26 4,50 40,28 2,48 n.d 3,10

5 Land 0-2 [mg/kg dw] 1,48 0,21 4,12 5,29 4,25 116,50 4,66 n.d 4,66

6 Land 0-2 [mg/kg dw] 7,34 0,59 25,47 15,36 18,65 102,77 7,53 0,03 11,37

7 Land 0-2 [mg/kg dw] 8,71 0,50 39,59 22,09 23,75 109,78 8,99 0,03 12,64

8 Marine 0-2 [mg/kg dw] 5,80 0,42 22,71 15,26 13,49 94,22 4,95 0,04 11,17

9 Marine 0-2 [mg/kg dw] 7,16 0,48 25,67 17,38 14,73 106,39 5,56 0,05 12,17

9 Marine 10-12 [mg/kg dw] 5,35 0,66 26,81 20,53 17,81 122,23 6,44 0,05 14,04

9 Marine 20-22 [mg/kg dw] 7,50 1,65 34,03 26,83 22,44 181,07 8,12 0,13 32,66

10 Marine 0-2 [mg/kg dw] 7,98 0,38 27,00 16,84 15,59 108,84 6,04 0,05 12,56

10 Marine 10-12 [mg/kg dw] 4,51 0,40 12,91 8,89 9,35 56,31 3,44 n.d 5,34

11 Marine 0-2 [mg/kg dw] 6,09 0,38 24,06 14,99 13,54 99,74 5,27 0,04 11,44

11 Marine 10-12 [mg/kg dw] 6,39 0,75 29,75 18,14 18,91 108,61 6,89 0,03 11,98

11 Marine 20-22 [mg/kg dw] 5,60 0,90 37,46 22,40 23,97 106,92 8,53 0,01 12,51

12 Marine 0-2 [mg/kg dw] 10,22 0,62 33,31 23,38 18,58 130,10 7,21 0,05 16,19

13 Marine 0-2 [mg/kg dw] 5,30 0,33 20,05 13,01 11,37 92,48 5,87 0,03 11,76

13 Marine 10-12 [mg/kg dw] 2,78 0,23 11,92 8,14 7,17 63,89 3,92 0,02 8,17

14 Marine 0-2 [mg/kg dw] 8,18 0,56 32,58 22,57 18,70 132,88 7,78 0,07 17,38

Stations Unit Arsenic Cadmium Chromium Copper Nickel Zinc Cobalt Mercury Lead

As Cd Cr Cu Ni Zn Co Hg Pb

SEKTION 1 ÖST mg/kg dw 12,38 0,36 31,32 26,25 16,81 148,23 6,48 0,07 15,48

SEKTION 1 W mg/kg dw 17,81 0,41 41,67 33,31 21,19 182,40 7,99 0,10 20,67

SEKTION 3 MITT mg/kg dw 17,09 0,21 36,43 30,32 19,61 147,23 7,03 0,16 23,31

SEKTION 2 OST mg/kg dw 11,38 0,22 28,62 24,49 16,12 136,90 6,02 0,10 19,21

SEKTION 3 VÄST mg/kg dw 21,16 0,37 32,83 29,36 18,55 139,92 5,93 0,14 20,98

SEKTION 2 VÄST mg/kg dw 8,22 0,16 21,75 19,15 12,87 109,31 4,58 0,07 13,82

SEKTION 3 ÖST mg/kg dw 21,16 0,18 36,44 36,38 20,81 175,05 7,11 0,15 23,36

SEKTION 2 MITT mg/kg dw 16,28 0,27 39,10 30,98 21,07 163,17 7,48 0,16 23,89

SEKTION 1 MITTEN mg/kg dw 13,62 0,32 31,16 25,68 18,08 141,49 6,18 0,07 15,04

BUR 1 SYD mg/kg dw 14,51 0,43 32,80 28,09 18,17 154,34 6,67 0,06 15,49

MALIN mg/kg dw 5,29 0,07 9,41 11,72 6,11 69,85 2,41 0,03 8,03

12

Cobalt (Co), Nickel (Ni) and Lead (Pb), have class 1 concentrations on all the surface

sample stations over the Sannäsfjord (Fig. 3 & 4).

Chrome (Cr), Section 1, station West have a class 2 concentration, but all other stations

belong to class 1 (Fig. 4).

Copper (Cu), stations 1,6 and 7 are the stations in class 2 of the land-samples. The marine

stations 8, 9, 12 and 14 also belong in class 2. The highest concentrations can be found in

the three sections (Fig. 4, Table 3 & 4). The marine samples (from 2016) generally have

higher concentrations with an exception of station Malin and section 2 East sample than the

ones from 2017 (station 8 to 14).

Mercury (Hg), the surface sample shows the highest concentrations of mercury in section 3

and the middle station of section 2, but also stations 1 and 2 on land near the landfill

Falkeröd. Stations 4 and 5 have undetectable concentrations. Stations in class 2 are section

2s east and west samples, section 1, bur 1 syd and all the marine stations from 2017 except

13 (Fig. 3, Table 3 & 4).

Zinc (Zn), figure 3 shows class 3 concentrations over the whole fjords marine stations from

2016, except at station Malin and station west in section 2. The deeper station 14 also

classify as class 3, as well as station 12. Class 1 to class 2 concentrations can be found on

land and near the shore (Fig. 3).

3.2.2 Normalized Samples and Stratigraphy

Normalized samples

Comparing the marine samples (stations 8-14) with the land samples (stations 1-7),

the marine samples generally show a higher signal together with land-station 7 (Fig. 6-9),

due to less carbon in the samples. This is accurate for a majority of the heavy metals.

Station 1 and 2 have the weakest signal out of all the heavy metals, but they also consist of

more carbon and nitrogen than the other land samples. Station 3, 6 and 7 have higher

normalized values (Fig. 6,7 & 8) in comparison to other land-samples, the C/N-quota also

matches some of the marine samples for station 3,6 and 7 (Fig. 12). This may indicate

marine sediments located above the present sea level. Zinc and Cobalt have a stronger

signal at station 5 (Fig. 8) with respective values of 56 mg/kg OC and 2 mg/kg OC. The

normalized values for cadmium are relatively alike and lies around 0,1, except for the

stratigraphic samples from station 9 and 11, that have significantly higher values downcore

(Fig. 7). A noticeable higher mercury and lead signal is found in stratigraphic samples

downcore at station 9, 20-22 cm, while station 11 have decreasing values of the metals

downcore (Fig. 9).

13

Figure 3: The analyzed concentrations of Lead (Pb), Zinc (Zn), Nickel (Ni) and Mercury (Hg) in the surface sediments (0-2 cm) on each station in the Sannäsfjord, data from April 2017 (station1-14) and August 2016. Classified according to table 2.

Zink-Zn Lead-Pb

Nickel-Ni Mercury-Hg

14

Figure 4: Analyzed concentrations of Copper (Cu), Chrome (Cr), Cobalt (Co) and Cadmium (Cd) in the surface sediments (0-2 cm) on each station in the Sannäsfjord, data collected April 2017 (station1-14) and August 2016. Classified according to table 2.

Copper- Cu Chromium-Cr

Cobalt-Co Cadmium-Cd

15

Figure 5: The analyzed arsenic concentrations in the surface sediments (0-2 cm) of the

Sannäsfjord, data collected April 2017 (stations1 to14) and August 2016. Classified

according to table 2.

Figure 6: Shows the normalized (mg/kg OC) and absolute concentrations (mg/kg dw) of

stations 1 to 14 (Fig. 1 & 2), stratigraphic samples included (stations 9 and 11). Data from

the Sannäs fjords sediment surface samples taken on 1-2 April 2017. The green line

represents class 2 (table 2), and the dashed line separates the samples taken at land

(station 1-7) from the marine samples (8-14).

0

2

4

6

8

10

12

1 2 3 4 5 6 7 8 99

, 10

-12

9,2

0-2

2

10

10

,10

-12

11

11

,10

-12

11

,20

-22

12

13

13

,10

-12

14

Arsenic

Normalized (mg/kg OC) As (mg/kg dw)

Arsenic-As

16

Figure 7: Shows the normalized (mg/kg OC) and absolute concentrations (mg/kg dw) of

cadmium, chrome and copper at stations 1 to 14 (Fig. 1 & 2), stratigraphic samples included

(stations 9 and 11). Data from the Sannäs fjords sediment surface samples taken on 1-2

April 2017. The green, yellow and orange lines represents deviation classes (table 2), and

the dashed line separates the samples taken at land (station 1-7) from the marine samples

(8-14).

0

0,5

1

1,5

2

1 2 3 4 5 6 7 8 99

, 10

-12

9,2

0-2

2

10

10

,10

-12

11

11

,10

-12

11

,20

-22

12

13

13

,10

-12

14

Cadmium

Normalized (mg/kg OC) Cd (mg/kg dw)

0

10

20

30

40

50

1 2 3 4 5 6 7 8 99

, 10

-12

9,2

0-2

2

10

10

,10

-12

11

11

,10

-12

11

,20

-22

12

13

13

,10

-12

14

Chromium

Normalized (mg/kg OC) Cr (mg/kg dw)

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 99

, 10

-12

9,2

0-2

2

10

10

,10

-12

11

11

,10

-12

11

,20

-22

12

13

13

,10

-12

14Copper

Normalized (mg/kg OC) Cu (mg/kg dw)

17

Figure 8: Shows the normalized (mg/kg OC) and absolute concentrations (mg/kg dw) of

nickel, zinc and cobalt at stations 1 to 14 (Fig. 1 & 2), stratigraphic samples included

(stations 9 and 11). Data from the Sannäs fjords sediment surface samples taken on 1-2

April 2017. The green, yellow and orange lines represents deviation classes (table 2), and

the dashed line separates the samples taken at land (station 1-7) from the marine samples

(8-14).

05

1015202530

1 2 3 4 5 6 7 8 9

9, 1

0-1

2

9,2

0-2

2

10

10

,10

-12

11

11

,10

-12

11

,20

-22

12

13

13

,10

-12

14

Nickel

Normalized (mg/kg OC) Ni (mg/kg dw)

0

50

100

150

200

1 2 3 4 5 6 7 8 99

, 10

-12

9,2

0-2

2

10

10

,10

-12

11

11

,10

-12

11

,20

-22

12

13

13

,10

-12

14

Zinc

Normalized (mg/kg OC) Zn (mg/kg dw)

0

2

4

6

8

10Cobalt

Normalized (mg/kg OC) Co (mg/kg dw)

18

Figure 9: Shows the normalized (mg/kg OC) and absolute concentrations (mg/kg dw) of

mercury and lead at stations 1 to 14 (Fig 1 & 2), stratigraphic samples included (stations 9

and 11). Data from the Sannäs fjords sediment surface samples taken on 1-2 April 2017.

The green and yellow lines represent deviation classes (table 2), and the dashed line

separates the samples taken at land (station 1-7) from the marine samples (8-14).

Stratigraphy

The stratigraphy of station 9 and 11 (Fig. 10) have similar patterns when it comes to

Cd, Cr, Co, Cu and Ni were the absolute concentrations increase down to 20 cm, but the

pattern varies with the As, Hg, Pb and Zn concentrations. Station 11 have a small variation

between its stratigraphic values on a majority of the heavy metal concentrations, the Hg

concentration are the only one with a visible increase towards the surface. Station 9 heavy

metal concentrations increase towards the depth (20-22 cm) were cadmium concentrations

start to match class 4, while zinc and cadmium concentrations match class 3 (Table 3).

Station 10 and 13 concentrations decrease downcore (Fig. 10) for all the metals. The

concentrations however do not differ that much. Except for stations 10 and 13 zinc and

copper values, where the surface concentrations classify as class 2 and the concentrations

downcore as class 1 (Table 3).

0

0,02

0,04

0,06

0,08

0,1

0,12

0,14

Mercury

Normalized (mg/kg OC) Hg (mg/kg dw)

0

5

10

15

20

25

30

35

Lead

Normalized (mg/kg OC) 208 Pb (mg/kg dw)

19

Figure 10: Shows the concentrations of As, Cd, Cr, Co, Hg, Pb, Cu, Ni and Zn (mg/kg dw)

down in the sediments on station 9 and 11 in the Sannäsfjord, data taken on 2 April 2017.

Station 10 have no 10-12 cm concentration for mercury.

0

5

10

15

20

25

0 10D

epth

[cm

]Concentration (mg/kg

dw)

As

9

11

10

13

0

5

10

15

20

25

0 2

Dep

th [

cm]

Concentration (mg/kg dw)

Cd

9

11

10

13

0

5

10

15

20

25

0 50

Dep

th [

cm]

Concentration (mg/kg dw)

Cr

9

11

10

13

0

5

10

15

20

25

0 30

Dep

th [

cm]

Concentration (mg/kg dw)

Cu

9

11

10

13

0

5

10

15

20

25

0 25

Dep

th [

cm]

Concentration (mg/kg dw)

Ni

9

11

10

13

0

5

10

15

20

25

0 200

Dep

th [

cm]

Concentration (mg/kg dw)

Zn

9

11

10

13

0

5

10

15

20

25

0 10

Dep

th [

cm]

Concentration (mg/kg dw)

Co

9

11

10

13

0

5

10

15

20

25

0 0,15

Dep

th [

cm]

Concentration (mg/kg dw)

Hg

9

11

10

13

0

5

10

15

20

25

0 40

Dep

th [

cm]

Concentration (mg/kg dw)

Pb

9

11

10

13

20

3.3 Carbon and Nitrogen:

The Nitrogen distribution in the sediments shows variation between the different

stations and depths (Fig. 11). The red staples, representing the samples taken on land

shows that station 1 and 7 have the highest levels (over 0,6 and 0,5 %) of nitrogen. Stations

3, 4 and 5 have the lowest value of the terrestrial samples. The marine stations surface

sediment samples 8,10 and 11 have all their values at around 0,3 % nitrogen. The surface

sample from station 12 have the highest concentration around 0,6 %. All samples taken from

the 10-12 cm interval have a lower value than the surface-samples, but the nitrogen content

increase from 12 cm to the 20-22 cm interval at station 9 and 11. There is a total variation

from 0,1 to 0,6 in the TN-samples.

The TOC (total organic carbon) values follow a similar pattern as the TN (total

nitrogen) values (Fig. 12), but stations 4 and 5 have the lowest carbon values. Station 9 and

11s carbon values increase at 20-22 cm. TOC-values varies from 2 to 8 %.

The C/N-quota does not follow the same pattern as the carbon and nitrogen values

(Fig. 12). The highest values can be found at the land stations, where station 5 has the

highest value around 20. Stations 1 to 4 both have similar values with small variations and

station 6 and 7 values at 11. The marine surface samples (station 8 to 14) have a value

around 9, except station 13 that has a value above 12. The C/N-quota increase with the

depth except on station 11 were the highest value is in the 10-12 cm interval. The total

variation of the C/N-quota is 8 to 19.

Figure 11: Presents the Total Nitrogen (TN) content (%) in the surface sediment samples (0-

2 cm) from 2017. The red stations 1 to 7 are the ones located on land and the blue stations 8

to 14 are the marine station, also including samples from 10-12 cm and 20-22 cm on stations

9,10,11 and 13.

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

Stations

TN [%]

21

Fig 12: Shows the total organic carbon (TOC)(%), total nitrogen(TN)* 10 (%) and C/N-quota

on each station from 2017. The dark grey stations (C/N) 1 to 7 are the samples based on

land, and the light grey (C/N) station 8 to 14 are the marine samples (Fig. 2). Stations

9,10,11 and 13 also shows values from 10-12 cm and 20-22 cm (9 and 11). TN is multiplied

with 10 only for better visuals and comparisons to the other values, when looking for trends

in the sediments.

4 Discussion

Hydrographic impact

The hydrographic patterns and processes in the fjord affect the heavy metal

distribution and is important to have in mind when discussing potential pollutions sources.

The signs of up-welling seen in the innermost part of the fjord (Nordberg et al, 2012)

may contribute to the elevated values noticed downcore (Fig. 10). Water from the deep basin

and Sannäs area transport polluted particles to the inner most part, and later settle in the

calm bays. This mechanism might also transport sediment in the opposite direction, out of

the area, by resuspension during such events (Nordberg et al, 2012).

The highest metal concentrations in the surface sediment at the innermost part, are

found at station 14 and 12, where cadmium and zinc have a class 3 deviation (Fig. 3 & 4).

Station 12 and 14 are located close to Skärboälven outflow and are influenced by the

streams freshwater, but they are also influenced by the intermediate waters due to their

water depth (4-5 m). Flocculation and accumulation occurs when the fresh surface water

meets the saline intermediate water.

The low concentrations of station 13 (table 3) might be due to its location very close to

the streams outlet, since the stream transport away material to the rest of the fjord.

Contaminants from the streams increase when wind and precipitation is higher, forcing water

out from the shores (Ödalen, 2012). The fjord horizontal surface circulation pattern might

also bring pollutants from outside the fjord into the innermost deeper parts. Pollutants from

leisure boat activities and the Sannäs village could also travel within this circulation pattern.

0

2

4

6

8

10

12

14

16

18

20

TN, TOC [%] and C/N-quota

TOC (%)

C/N

TN*10 (%)

22

Environmental status in recent surface sediments in the Sannäs fjord

The heavy metal concentrations in the fjord have shown to be modest and not

alarming according to SEPAs (2000) classification (table 2). Chromium, nickel, cobalt and

lead have class 1 concentrations, showcasing a clean environment with no deviation from

the background concentrations. Arsenic, cadmium copper zinc and mercury have

concentrations in class 2 & 3, showing variation from the background values indicating

contamination. Cadmium has the highest concentrations at the innermost part of the fjord

and on land (Fig. 4). The surface sediments are relatively clean, but some of the metals

show higher concentrations than what were reported in Nordberg et al (2012) from 2008

(table in Appendix B). Arsenic have increased in stations south of Sannäs and in section 3

(Fig. 5) from class 2 to class 3 (table 4). Cobalt, chrome and nickel concentrations are

almost unchanged compared to the 2008 values and are still in the same environmental

class. Lead has decreased on the stations in section 2 and 3, since 2008. The station named

Malin outside the mouth of the fjord have class 1 values on all elements studied, and

comparing to Nordberg et al (2012) station SSK08-9 (the nearest station to Malin) has

decreased since 2008.

Cadmiums concentration and classification is mostly unchanged from 2008 and the

higher concentrations found in the innermost part of the fjord had not been examined before

(Fig. 4). Another increasing heavy metal concentration in the fjord is copper. The increase is

seen by class 2 concentrations in the innermost parts to gradually increase to class 3 along

the fjord to the mouth (Fig. 4). The mercury concentrations are mainly unchanged since

2008, except for section 3 where it has decreased from class 4 to class 3. A gradual

increase from the innermost parts towards the mouth is seen also for Hg (Fig. 3). The zinc

concentrations have increased since 2008 in a majority of the stations of the fjord, and is one

of the most characteristic metals in the fjord, generally with class 3 concentrations (Fig. 3).

Even though there is an increase of arsenic, zinc and copper, the values do not

deviate much from the 2008 values. It is more like a slight increase on certain stations in the

fjord with zinc being the most prominent. This suggests that the fjord is continuously

subjected to pollution from various sources. Copper and zinc in the fjord correlate to leisure

boat-activities, anti-fouling paint and activities in the Sannäs village (Nordberg et al,2012).

Nordberg et al (2012) suggest that the higher mercury concentration from 2008 in one single

location is the result of an unknown local anomaly/point source, and it is still visible (Fig. 3).

Arsenic can be found in paint, impregnating agents and certain pesticides and its

concentrations in the surface sediments are highest at section 3, together with Hg and Cu

(Fig. 3 to 5). Agricultures artificial fertilizers probably contribute to the higher Cd values at the

innermost part. The run-off from the stream Skärboälven (0,5-1 m3/s) and from land

probably contribute to the cadmium levels because of its large drainage area from farm

lands (Ödalen, 2012) (Fig. 1). The cleanliness of the surface sediments in the fjord, its

innermost part and on land today does not indicate pollution from the landfills.

The differences in concentrations between 2008 and 2016/2017 are not large and

therefore could also be a result of different ICP-MS machines and models. The reaction gas

N2O used in the ICP-MS analysis in this study may show more accurate values than the

reaction gas He used in previous studies, or other methods used in the 2008 study

(Nordberg et al 2012). It is also important to note that most stations from 2016 and 2008 are

23

not from the same positions. This may be part of the discrepancy between the samples

collected (Fig. 2 & Nordberg et al, 2012).

Diatoms and Cadmium

A factor that may contribute to the higher cadmium levels at the innermost part of the

fjord, are the diatoms. Studies have shown that certain species of diatoms of the genus

Thalassiosira, store cadmium with the help of specific enzymes when Zn-concentration is

low (Lane and Morel, 2000 & Lane et al, 2005) and since the diatoms later accumulate, so

does the cadmium. Since there is no modern data of the different species of diatoms in the

Sannäs fjord this is presently just a hypothesis. However, the fjord has a diatom flora and

assemblages together with resting cyst of Thalassiosira have been discovered in fjords such

as Koljöfjorden and the Gullmar fjord on the Swedish west coast (McQuoid, 2002, 2005 and

McQuoid & Nordberg, 2003). Since the fjords on the west coast are affected by the same

currents from Skagerrak and Kattegat, there is a possibility for Thalassiosira to be a part of

the Sannäs fjords flora. A study in this area would be of interest.

Carbon and nitrogen on land and at the innermost parts of the fjord

High carbon and nitrogen levels can be found on stations 1 and 2 near the landfill

Falkeröd. It is possible that the high values are a natural result from their position in an alder

fen, that accumulate large amounts of organic carbon and nitrogen together with heavy

metals from the surrounding surface and groundwater run-offs (Flodin, 2008). The Sample

from station 5 taken near the landfill Olseröd have low values of nitrogen, but the sample

was taken in flowing water. Hence the coarse sediments suggesting a removal of finer

sediments and biogenic compounds. Higher total nitrogen (TN) levels can also be found on

stations 6 and 7 samples since they consist of elevated marine sediments as a result of the

ongoing land uplift, and may also be enriched by the grazing cattle and numerous grazing

geese (Fig. 1). The bird-reserve probably impacts the nitrogen levels in the fjord (Ruess et

al, 1989, Olson et al, 2005 & County Administrative Board of West of Götaland, 2017). The

shore is exposed to the agriculture areas via ditches through the fjord, surface runoff from

surrounding land and the stream Skärboälven. The stream contributes with 34 tons /year of

nitrogen, where 51 % comes from anthropogenic sources from which a majority comes from

the surrounding agriculture. The Sannäs fjord has a contribution of 45 tons of nitrogen per

year into the fjord (Ödalen, 2012; County Administrative board of West of Götaland, 2017).

The C/N ratios in the innermost area of the fjord are, however, similar for the entire fjord

extension (Nordberg et al., 2012).

The C/N-levels of the marine samples are the lowest and especially in the surface

layer because of its marine influenced organic matter from the outside, rich in protein and

nitrogen. Terrestrial organic matter contains relatively more carbon because of cellulose

(Cato, 1992). The C/N levels on land are generally higher than the marine samples. When

looking downcore in the sediments a slight increase of TOC and the C/N-ratio is seen at 20-

22 cm (Nitrogen degrades faster than Carbon, which is a natural process during the

diagenesis). Station 11 have its highest C/N-value at 10-12 cm, but the sediments may be

mixed due to bioturbation. According to Nordberg et al (2012) C/N-values between 8 and 9

indicate “a nutritional environment” and have a high primary production. The increase

downcore may suggest a more productive time with more nutrients, maybe from agriculture

or the outlet from a previous nearby laundry (Fig. 12).

24

Stratigraphy

A majority of both absolute and normalized heavy metal concentrations increase

downcore, showing a more polluted environment in the Sannäs fjords innermost part (Fig. 10

& Table 3). When comparing the stratigraphic samples (Fig. 10) with the previously

investigated stations SSK08-1 and SSK08-2,5 (figures in Appendix A) stratigraphy, a similar

heavy metal concentration pattern is found with values in the same range (Table 3). This is

especially relevant for station 9, 20-22 cm sample. Arsenic do not have the same linear

pattern on station 9 and 11 and in contrast to station SSK08-1 (Appendix A), but the

concentrations are even so relatively similar. Mercury is also a bit off comparing to station 9

stratigraphic values, since neither the values nor signal pattern is alike. Zinc levels are a bit

higher and lead a bit lower in contrast to SSK08-1 samples. The highest absolute heavy

metal concentrations of cadmium, copper, zinc, mercury and lead are found at station 9, 20-

22 cm sample and is similar or lower to stations SSK08-01 &2,5 from 2008 (Appendix A) and

the core from Robijn (2012) concentrations. The exception being cadmium which have a

higher concentration than previously mentioned downcore in class 4 at station 9. High values

of cadmium are also found at station 11, 20-22 cm sample.

Mercury pickled seed was banned 1966 (SIME, 2010) which could explain the

decrease of mercury up-core on station 9. Station 11 and 13 are probably influenced by the

terrestrial material from the shore, due to the shallow depths (table 1).

Station 9 is located near a small pier and the concentrations could be due to a local

anomaly. But it is most likely due to the general time signal pattern from pollutions, similar

over the whole fjord. The ban of cadmium in plastic products was effected in 1982

(Bergsbäck et al, 1994) and corresponding decrease could be seen in the stratigraphic

records, even though there still is a lot of Cd spread by the agriculture (Fig. 11). Cadmium is

also a compound in old plastic waste which could be found at landfills, so there is a

possibility that historically the landfills could have contributed to the higher concentrations of

heavy metals downcore, but later declined since the landfills closed. This theory is also

supported by the higher C/N-quota downcore, that may indicate a higher terrestrial input or

more nitrogen from leachate.

Landfills and ditches

For the metals to reach the fjord from the landfills, it needs to be transported as

leachate through the ditches and via groundwater (SEPA, 2008). By studying figures 3-5 it is

difficult to find indications for the closed landfills to be point sources for the metals

documented in the most recent fjord sediments. Cadmium is the only metal with its highest

concentrations near the innermost part, and is also visible at certain land stations such as

station 1 and 6. Zinc also has somewhat higher concentrations in the innermost part, but

lower values at the terrestrial stations (Fig.3).

Factors that may support the hypothesis that the closed landfills affect the fjord and its

surroundings, are the normalized zinc and cobalt values at station 5 (Fig.8). Station 5 with

higher normalized values of zinc (Fig. 8), could have a connection to zinc found in e.g.

galvanized scrap and batteries at the landfill, indicating a contamination signal. Station 5

slope and sediment texture suggest water transported away from the area, explaining the

low values of carbon and nitrogen as well as the low absolute heavy metal concentrations

(Fig. 11 &12). Another a factor suggesting landfill contamination are the slightly higher

concentrations of cadmium (class 3), mercury and copper (class 2) on station 1 and 2, that

25

have accumulated in the alder fen (Table 3). However, it is also possible that other nearby

contamination sources contributed to these values (Web-GIS, 2010 & Flodin, 2008), but

these theories are unsupported by the normalized values. The long distance from station 1

and 2 to the fjord through ditches also lower the distribution risk-factor (Table in Appendix B).

Higher nitrogen levels could also be an indicator of leachates, found in station 1,2,6,7,12,14

and 9 and 11s core samples at 20-22cm. However as discussed above, the nitrogen could

have originated elsewhere. The station 5 ditch is resembling many other leachate ditches

found in the region West of Götaland with its rusty sediments. It was probably used as a

drainage and leachate ditch from the landfill, since a stented dyke has been constructed and

connected to it (Environmental Cooperation West of Götaland, 2010).

The ditches connecting the fjord with the landfills have very fine sediment particles

which indicate slow to non-transportation of water. Since the landfill stations are classified as

moderate risks including the criteria for distribution (Table included in Appendix B) and the

low heavy metal concentrations, the impact from the landfills to the fjords sediments are

presently not observed. The heavy metal concentrations in the surface sediments today is

likely caused by other activities in the area. However, it is still possible that the landfills

affected the area in the past.

Many of the above mentioned factors may explain the low metal concentrations in the

innermost sediments and the slightly higher zinc, copper and cadmium pattern in the rest of

the fjord and in the stratigraphy (Fig. 3 & 4). Arsenic, cadmium, copper and zinc

concentrations, and also carbon and nitrogen values shows that the fjord still is subjected to

pollution. But, the closed landfills have no effect on the Sannäs fjord recent sediments. The

area is relatively clean from heavy metals and continues being affected by processes and

activities inside the fjord and from the larger freshwater outlets. The general perception that

the closed landfills leak pollutants to the fjord is not accurate today, but could have been

accurate before 1974. Since the County administrative board already classified the landfills

as relatively low risks and have plans of action regarding old landfills, the fjord should be

safe from landfill-pollution. No outstandingly high heavy metal concentrations were found at

the innermost stations in Nordberg et al (2012) study either.

5 Conclusion

- The recent heavy metal concentrations in the surface sediments at the Sannäs

fjord indicate a relatively good environmental status, with slight decreases of many

metals in the sediments. But there is also a slight increase of arsenic, zinc and

copper since 2008. This suggests that the fjord is continuously subjected to

pollution, probably due to the boat-activities in the fjord and contributions from

freshwater inflows, all in combination with the hydrography of the fjord.

- Agricultural activities appear to affect the innermost part of the fjord with its

cadmium, zinc and nitrogen. These elements are supposed to come to the fjord

mainly through the stream Skärboälven but also from the ditches and freshwater

runoff from land. Grazing birds and cattle probably also contribute to the elevated

nitrogen values.

26

- The contaminants may be transport away from the innermost area by the estuarine

circulation but also transported into this area via the deeper corresponding in-

transport and by upwelling.

- The former landfills do not seem to affect the fjords recent sediments. The

concentrations are too low, compared to the rest of the fjord. The area is generally

classified as class 1 and class 2 i.e. Non/insignificant or slight deviation from

background values. If the landfill had an ongoing outflow of metals it probably

would have been noticed in previous studies. However:

o Only one location, Station 5 is probably the most certain place affected by

leachates. Because of higher normalized zinc (and cadmium) values, as

well as the sediments rusty character as in a draining ditch.

o It is still uncertain if the landfills affected the fjord sediments in the past.

6 Acknowledgment

I would like to thank professor Kjell Nordberg for supervising and guiding this project,

but also for the possibility to the collect samples and getting access to unpublished research

material from the fjord. I would also like to acknowledge Johan Hogmalm, Ardo Robijn and

Irina Polovodova-Asteman for the help with the technical and chemical analyses.

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30

Appendix A

Stratigraphies from SSK08-1 and SSK09-2,5 displaying arsenic, cadmium, cobalt, chrome,

copper, mercury, nickel, lead, vanadium and zinc. Also organic carbon and water content.

Arsenic, copper, mercury, nickel and vanadium is missing from SSK09-2,5. Data from

Nordberg et al (2012).

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

45

40

35

30

25

20

15

10

5

0

0 4 8 12

Depth

in c

ore

(cm

)

Depth (cm)

As mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 2 4 6 8 10

Co mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 10

20

30

40

50

Cr mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 10 20 30

Cu mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 0,0

2

0,0

4

0,0

6

0,0

8

0,1

Hg mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 5 10

15

20

25

Ni mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 10

20

30

40

Pb mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 0,2

0,4

0,6

0,8

1

Cd mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B0 2

0

40

60

80

V mg/kg dw

BB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 50

100

150

200

Zn mg/kg dw

BB

BBBB

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

B

0 1 2 3 4 5

Org. C

BB

BBBBBBBBBBBBBBBBBB

B

B

B

B

B

B

B

B

B

B

0 100

200

300

400

500

Water content (%) dw

SSK08-1A

2008

1975

1950

1935

1920

~ År

1910

31

Appendix B

Coordinates, water depth, time and stations from Nordberg, unpublished data, 2016.

Nordberg et al (2012), 2008 surface concentrations for: Arsenic, cadmium, cobalt, chromium,

copper, mercury, nickel, lead, vanadium and zinc. Also accumulation contribution (mm/year)

to the sediments..

Table from SEPA (1999) explaining the principles for classification on the category

distribution for landfill pollutants.

Station-ID Long (WGS 84) Lat (WGS 84) Water depth [m] Time Date (2016)

SEKTION 1 ÖST E11°14.76 N58°44.04 - 13:20 15-aug

SEKTION 1 W E11°14.56 N58°44.03 - 11:48 15-aug

SEKTION 3 MITT E11°12.21 N58°45.51 17,5 m 16:07 15-aug

SEKTION 2 OST E11°13.67 N58°44.73 9 m 14:17 15-aug

SEKTION 3 VÄST E11°12.02 N58°45.53 14,5 m 16:30 15-aug

SEKTION 2 VÄST E11°13.52 N58°44.71 12 m 14:57 15-aug

SEKTION 3 ÖST E11°12.44 N58°45.50 20 m 15:45 15-aug

SEKTION 2 MITT E11°13.60 N58°44.71 14 m 14:32 15-aug

SEKTION 1 MITTEN E11°14.67 N58°44.02 - 13:05 15-aug

BUR 1 SYD E 11°14.89 N 58°43.65 - 10:48 15-aug

MALIN E 11° 11,31 N 58° 46,53 18 m 17:03 15-aug

Station Enhet Arsenik Kadmium Kobolt Krom Koppar Kvicksilver Nickel Bly Vanadin Zink Ackhast

As Cd Co Cr Cu Hg Ni Pb V Zn mm/år

SSK08-1 mg/kg TS 8,0 0,41 7,5 33 23 0,10 20 22 59 121 2,0

SSK08-2 mg/kg TS 9,7 0,37 7,5 38 24 0,08 21 21 66 118 4,0

SSK08-2,5 mg/kg TS 9,4 0,43 6,4 33 22 0,09 18 21 58 105 4,2

SSK08-4 mg/kg TS 14 0,24 8,0 44 28 0,17 23 28 78 130 2,8

SSK08-6,5 mg/kg TS 17 0,34 6,4 37 27 0,51 22 31 57 107 2,2

SSK08-7 mg/kg TS 9,9 0,19 5,7 32 21 0,31 18 25 52 85

SSK08-9 mg/kg TS 14 0,30 5,9 32 32 0,19 20 24 52 83

32

Appendix C

The total nitrogen (*10), total organic carbon, total nitrogen, C/N-quota and normalized

heavy metal values from 2017 stations.

Station Centimeters Unit Arsenic Cadmium Chromium Copper Nickel Zinc Cobalt Mercury Lead

[cm] As Cd Cr Cu Ni Zn Co Hg Pb

1 0-2 [Conc]/[TOC] 0,20 0,08 0,88 2,30 1,12 7,05 0,39 0,01 1,42

2 0-2 [Conc]/[TOC] 0,28 0,05 1,35 1,35 0,79 7,80 0,31 0,01 1,73

3 0-2 [Conc]/[TOC] 1,65 0,14 4,24 4,29 3,46 25,82 1,79 0,01 2,09

4 0-2 [Conc]/[TOC] 1,22 0,13 3,89 3,09 2,64 23,64 1,45 1,82

5 0-2 [Conc]/[TOC] 0,72 0,10 2,01 2,58 2,07 56,86 2,28 2,28

6 0-2 [Conc]/[TOC] 1,75 0,14 6,07 3,66 4,45 24,50 1,80 0,01 2,71

7 0-2 [Conc]/[TOC] 1,54 0,09 7,00 3,91 4,20 19,42 1,59 0,01 2,24

8 0-2 [Conc]/[TOC] 1,94 0,14 7,61 5,11 4,52 31,58 1,66 0,01 3,74

9 0-2 [Conc]/[TOC] 1,66 0,11 5,94 4,03 3,41 24,63 1,29 0,01 2,82

9 10-12 [Conc]/[TOC] 1,29 0,16 6,47 4,95 4,30 29,50 1,56 0,01 3,39

9 20-22 [Conc]/[TOC] 1,55 0,34 7,05 5,56 4,65 37,50 1,68 0,03 6,76

10 0-2 [Conc]/[TOC] 2,54 0,12 8,60 5,36 4,97 34,66 1,92 0,02 4,00

10 10-12 [Conc]/[TOC] 1,85 0,16 5,29 3,65 3,83 23,08 1,41 2,19

11 0-2 [Conc]/[TOC] 1,96 0,12 7,74 4,82 4,35 32,08 1,70 0,01 3,68

11 10-12 [Conc]/[TOC] 1,73 0,20 8,08 4,92 5,13 29,49 1,87 0,01 3,25

11 20-22 [Conc]/[TOC] 0,86 0,14 5,73 3,43 3,67 16,36 1,30 0,00 1,91

12 0-2 [Conc]/[TOC] 1,90 0,12 6,21 4,36 3,46 24,24 1,34 0,01 3,02

13 0-2 [Conc]/[TOC] 1,81 0,11 6,86 4,45 3,89 31,63 2,01 0,01 4,02

13 10-12 [Conc]/[TOC] 1,33 0,11 5,69 3,89 3,43 30,52 1,87 0,01 3,90

14 0-2 [Conc]/[TOC] 2,02 0,14 8,02 5,56 4,61 32,72 1,91 0,02 4,28

Station-ID Centimeters [cm] TN *10 [%] TOC [&] C/N-quota TN [%]

1 0-2 6,41 8,43 13,15 0,64

2 0-2 4,38 5,40 12,32 0,44

3 0-2 2,08 2,70 12,98 0,21

4 0-2 1,22 1,70 13,95 0,12

5 0-2 1,06 2,05 19,29 0,11

6 0-2 3,66 4,19 11,47 0,37

7 0-2 5,09 5,65 11,10 0,51

8 0-2 3,35 2,98 8,90 0,34

9 0-2 4,94 4,32 8,74 0,49

9 10-12 4,15 4,14 9,99 0,41

9 20-22 4,68 4,83 10,31 0,47

10 0-2 3,20 3,14 9,83 0,32

10 10-12 1,93 2,44 12,64 0,19

11 0-2 3,20 3,11 9,70 0,32

11 10-12 3,08 3,68 11,96 0,31

11 20-22 5,70 6,54 11,48 0,57

12 0-2 5,94 5,37 9,04 0,59

13 0-2 2,41 2,92 12,15 0,24

13 10-12 1,60 2,09 13,07 0,16

14 0-2 4,34 4,06 9,36 0,43