In-Lake Processes Offset Increased Terrestrial Inputs of Dissolved Organic Carbon and Color to Lakes

Increased color in surface waters, or browning, can alter lake ecological function, lake thermal stratification and pose difficulties for drinking water treatment. Mechanisms suggested to cause browning include increased dissolved organic carbon (DOC) and iron concentrations, as well as a shift to more colored DOC. While browning of surface waters is widespread and well documented, little is known about why some lakes resist it. Here, we present a comprehensive study of Malaren, the third largest lake in Sweden. In Malaren, the vast majority of water and DOC enters a western lake basin, and after approximately 2.8 years, drains from an eastern basin. Despite 40 years of increased terrestrial inputs of colored substances to western lake basins, the eastern basin has resisted browning over this time period. Here we find the half-life of iron was far shorter (0.6 years) than colored organic matter (A(420); 1.7 years) and DOC as a whole (6.1 years). We found changes in filtered iron concentrations relate strongly to the observed loss of color in the western basins. In addition, we observed a substantial shift from colored DOC of terrestrial origin, to less colored autochthonous sources, with a substantial decrease in aromaticity (-17%) across the lake. We suggest that rapid losses of iron and colored DOC caused the limited browning observed in eastern lake basins. Across a wider dataset of 69 Swedish lakes, we observed greatest browning in acidic lakes with shorter retention times (< 1.5 years). These findings suggest that water residence time, along with iron, pH and colored DOC may be of central importance when modeling and projecting changes in brownification on broader spatial scales

Marine tourism and recreation in Sweden : A study for the Economic and Social Analysis of the Initial Assessment of the Marine Strategy Framework Directive

This report provides input regarding the marine recreation and tourism components of the ecosystem service approach to the Economic and Social Analysis of the Initial Assessment of the EU Marine Strategy Framework Directive. The main content of the report is the following. See also Figure 0.1 for an illustration that also provides an interpretation of the report in terms of the Drivers-Pressure-State-Impact-Response (DPSIR) framework.  Chapter 1 presents the general methodology followed in the report. It also gives an introduction to Swedes’ recreation in or at the sea.  Chapter 2 presents a number of definitions related to marine recreation and tourism. Six sectors of marine tourism are identified:  A. Cruise-ship traffic in marine waters B. International passenger ferry traffic in marine waters C. National passenger ferry traffic in marine waters D. Other commercial passenger transportation in marine waters E. Leisure boating in marine waters F. Holiday housing associated with marine recreation G. Commercial accommodation (e.g. hotels, camping sites, etc.) associated with marine recreation H. Same-day visits associated with marine recreation  For sectors A-E, the connection to marine waters is unambiguous since the activities in these sectors take place in marine waters. Sectors F-H have a less direct connection but are still relevant to include because a substantial proportion of these sectors is likely to depend on the enjoyment of marine recreation. However, including sectors F-H requires a reasonable and objective delimitation of these sectors. It was chosen to use  two alternative geographical definitions for these sectors; one (called MAX) that is likely to result in an overestimate of the sectors in relation to their association with marine recreation and one (called MIN) that is likely to result in an underestimate. The MAX definition is to include those parts of sectors F-H which are located in Swedish coastal municipalities or on islands in marine waters. The MIN definition is to include those parts of sectors F-H which are located in subdrainage basins that drain directly into coastal or transitional water bodies (typology from the Water Framework Directive, 2000/60/EG) (delavrinningsområden som avvattnas direkt till kustvattenförekomster eller övergångsvatten) or on islands in marine waters. Based on the classification of marine ecosystem services in Garpe (2008) and SEPA (2009) and a survey of people’s use of marine waters (SEPA, 2010a, 2010b), Chapter 2 identifies the following seven subcategories of the ecosystem service C1 Enjoyment of recreational activities:  C1.1  Swimming C1.2  Diving C1.3  Windsurfing, water skiing C1.4  Boating C1.5  Fishing C1.6 Being at the beach or seashore for walking, picnicking, sunbathing, visiting touristic or cultural sites, etc. C1.7  Using water-based transportation  Chapter 3 describes the extent of use of Swedish marine waters by the sectors of marine tourism. The findings are summarized in Tables 0.1 and 0.2, where the former is based on the MIN definition for sectors E-H and the latter is based on the MAX definition for these sectors. When interpreting the figures, note that turnover and employment are defined differently for the different sectors: For sector A, they are about passengers’ expenditures ashore and the jobs these expenditures create; for sectors B-D, turnover and employment are for the companies found in these sectors – for employment this implies an underestimation because a substantial part of the employment is accounted for in the country where ships are registered; and for sectors E-H, turnover and employment are about tourists’ spending when boating, having holiday housing, making use of commercial accommodation and making same-day visits and the jobs associated with this turnover. The tables illustrate the considerable extent of coastal and marine tourism in Sweden. For example, the estimated turnover of this part of the Swedish tourism industry is between SEK 58 578 million (MIN) and SEK 75 153 million. The turnover of the Swedish tourist industry as a whole in 2010 was SEK 255 000 million (Tillväxtverket, 2011), which means that coastal and marine tourism accounted for between 23 % (MIN) and 29 % (MAX) of the total turnover

Marine litter in Sweden : A study for the Economic and Social Analysis of the Initial Assessment of the Marine Strategy Framework Directive

The initial assessment (IA) of the implementation of the EU Marine Strategy Framework Directive (MSFD) includes an economic and social analysis (ESA). This analysis is about two areas: (1) the use of marine waters and (2) the cost of degradation of the marine environment. Marine litter is one descriptor relevant for assessing good environmental status (GES) within the MSFD. Based on the ecosystem approach this report provides information on marine litter in Sweden involving status of marine litter (amounts, composition, sources etc.), how marine litter affects the provision of ecosystem services and costs and benefits connected to marine litter. This report is based on a literature review and a survey carried out in October 2011 to Swedish organizations causing marine litter or affected by marine litter. From the literature review and the survey it was evident that there is a general lack of data on the status of marine litter in Sweden as well as a lack of socioeconomic data describing effects of marine litter. The literature review and the survey also show that marine litter is an urgent environmental problem that causes negative effects on the provision of ecosystem services and causes costs to affected organizations and to society as a whole.     The lack of data on marine litter might be explained by the fact that there is no uniform way in which marine litter is monitored and measured in Sweden. The data found of amounts of marine litter in Sweden only covered the coast of the North Sea and no data were found for the coast of the Baltic Sea. Data on composition of litter showed that the litter commonly consists of plastic, packages, oil cans and fishing equipment etc. The most important sources of marine litter are both based on land and at sea and involve the fishing industry, shipping sector, tourism sector and other recreational activities.Several ecosystem services are judged to be affected by marine litter including supporting, regulating, provisioning and cultural ecosystem services. There are however several policy instruments in place for handling marine litter. The main sources of marine litter are also covered by the current legislation. Marine litter and effects of marine littering has however been apparent in the literature review and the survey in this report. This indicates that the current policy instruments might be inefficient or need to be complemented. The development of marine litter is uncertain and is likely to depend of the drivers of marine litter. Potential drivers of marine litter are closely related to the sources of marine litter and probably involve changes in consumption levels (affecting the use of packages), coastal and marine recreation and tourism, commercial fishing and shipping.   Data on cost of degradation due to marine litter are scarce and the data collected only covered the coast of the North Sea. Cost data indicate that cleaning the beaches from marine litter in the province of Bohuslän in the northern part of the Swedish west coast costs about 5-10 MSEK yearly based on data from the survey and over 10 MSEK based on data from the literature review. Data on benefits of reduced marine litter are even more scarce. The benefits of reduced marine litter involve increased aesthetic values, increased possibilities for coastal and marine recreational and tourism

Comparison of observed (meas.) and modeled (calc.) absorbance for the 22 lake sites (•) in Mälaren at wavelengths of 254 nm (A₂₅₄ calc and A₂₅₄ meas) (A) and at wavelength 420 nm (A₄₂₀ calc and A₄₂₀ meas) (B) for the same 22 lake sites.

<p>Modeled absorbances were established using <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070598#eqn1" target="_blank">Eqs. 1 to 3</a>. In both graphs we used the eight stream inflows (ο) to Mälaren as validation samples using parameter values defined from the lake sites (Table S4 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070598#pone.0070598.s004" target="_blank">File S1</a>).</p

Change in absorbance at 420 nm (Δ A₄₂₀) per year using the Sen’s slope during the period 1990-2010 for 69 trend lakes across Sweden, against water residence time (WRT).

<p>(A) Lakes are indicated as those with median lake water pH > 6.5 (white circles ο) and below 6.5 (dark circles •). The two grey squares represent the observed rates of change for the Western (to the left) and Eastern Basins of Mälaren (to the right); (B) and plots of the calculated change in A₄₂₀ caused by either DOC_input (hyphenated curve) or Fe_coll (bold curve) when starting from a hypothetical value of change in A₄₂₀ of 0.5 yr^-1 at a WRT of 0 years and using the decay constants for DOC_input and Fe_coll from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070598#tab4" target="_blank">table 4</a> that were derived for Mälaren.</p

Change in absorbance measured at 420nm (A₄₂₀) in the three sampling points within the Western Basins A and B (•), and three sampling sites within the Eastern Basins C and E (ο) calculated as five year averages over 45 years (between 1967 and 2011).

<p>Change in absorbance measured at 420nm (A₄₂₀) in the three sampling points within the Western Basins A and B (•), and three sampling sites within the Eastern Basins C and E (ο) calculated as five year averages over 45 years (between 1967 and 2011).</p

Spatial variability of the modeled water residence time of Mälaren, with the age of water increasing from western to eastern basins.

<p>Lake basins are identified by letters (A–F), with lake sites (white diamonds) and streams sites (black diamonds, S1-S8). Basin D is identified in grey as it was not included in the hydrological water residence time model.</p

Changes to the concentration of (A) dissolved organic carbon (DOC), (B) absorbance at 420 nm (A₄₂₀), (C) colloidal Fe (Fe_COLL), and (D) the freshness index with increasing water residence time across Mälaren.

<p>Changes to the concentration of (A) dissolved organic carbon (DOC), (B) absorbance at 420 nm (A₄₂₀), (C) colloidal Fe (Fe_COLL), and (D) the freshness index with increasing water residence time across Mälaren.</p