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The original Monitoring Protocol has been changed somewhat, mainly because of outcomes from baseline studies. 

Distribution of Long-tailed duck (hávellur) on Lagarfljót River during summer.

Figure 1. Long tailed ducks on Lagarfljót river 2005-2019

There has been great variation in the numbers of long tailed ducks on Lagarfljót river since counting began in connection with the Kárahnjúkar powerplant in 2005. The number of long tailed ducks on Lagarfljót decreased significantly during the first years of operation of the powerplant in the period 2008 to 2012 (Figure 1). A possible explanation for this decrease was considered to be increased turbidity in the river in conjunction with the transfer of Jökulsá á Dal to Lagarfljót river with the introduction of Hálslón, but increased turbidity can reduce the Aithyini food conditions. It does not have to be, however, as a reduction could be seen as early as 2007 compared to the summer of 2006, but water transport did not begin until after the summer of 2007. Another possible explanation for fewer long tailed ducks on Lagarfljót during this period could be related to stock fluctuations, but little is known about the state of the stock in Iceland or whether the distribution has changed in any way.

In 2013 and 2014 the number of long tailed ducks increased again and reached a similar number as in the years 2005 to 2007, which again indicated that external factors are likely to have a greater effects on the number of birds counted on Lagarfljót river than the conditions in the river. In the summer of 2015 the number of long tailed ducks on Lagarfljót decreased again. The cold vawe was almost summer in the East Iceland, which may be a part of the explanation from this decrease from the previous year. From 2016 to 2019 the number of long tailed ducks has remained fairly constant on Lagarfljót river. The section on baseline conditions shows a figure showing the results of counts of three other species of ducks, which also indicate variability that is not necessarily related to the situation in the river.

Mynd 2. Hávellupar (varpeining). Ljósmynd SGÞ

Figure 2. Long tailed ducks. Photograph SGÞ

Figure 3. Development of breeding units (pairs, single nesting birds during the breeding season in nesting grounds, nests, eggs, nestlings), on one hand in Lagarfljót river and on the other hand in Hérað area from 2005-2019.

Further processing of data on long tailed ducks in the years 2005 to 2019 revealed that socalled breeding units, ie. pairs with nestlings, nests and orphaned nestlings, had increased in Lagarfljót river and elsewhere in the Héraðs area (Figure 3), while the number of long tailed ducks in the Lagarfljót river hand decreased (Figure 1). It can therefore be assumed that Lagarfljót is still a significant stop or destination for the breeding birds  of the species, despite the water transport in 2007.

Updated: May 1, 2020
Source: Landsvirkjun 2017, East Iceland Nature Research Center 2020

Graylag goose

The Graylag goose population was studied in 2005 and again in 2013. The results plus data, gathered by East Iceland Natural History Institute, suggest that water transport has limited impact on the Graylag goose population and that there is no grounds to monitor it in relation to the power plant.

Number of nesting Great skuas (skúmur) in Jökulsá á Dal river outwash plain.

Mynd 4. Skúmur. Ljósmynd HWS

Figure 4. Great skua. Photograph HWS

Number of Great skua has not changed beyond natural short-term fluctuations in the population. The development in number in 2005 - 2017 can be seen in Figure 5. Note that no counting was done in 2010 and 2012.

Figure 5. Number of Great skua (skúma) in the channel of Jökulsá á Dal river when the environmental impact assessment was made in 2000 (Guðmundur A. Guðmundsson et. al 2001) and results from monitoring in 2005 - 2009, 2011 and 2013-2016 (Halldór W. Stefánsson 2016) as well as counting the summer of 2017 and 2019 (unpublished). All the counting years, the same areas where examined in the same way.

Great skuas have been counted, since 2014, near the channel of Jökulsá á Dal river in connection with a studies on waterfowls there. In 2014 the lowest number of great skuas since 2000 was found but the following year the number had increased again. They decreased slightly in 2016 compared to the previous year but have been increasing steadily since then.

Updated: May 1, 2020
Source: Landsvirkjun, 2017 og East Iceland Nature Research Center, 2020

Metrics, Targets and Monitoring Protocol

What is measured?
  1. Long-tailed duck (hávella), Tufted duck (skúfönd) and Mallard (stokkönd) – distribution and count at Lagarfljót river during summer. (Project effect: indirect).
  2. Number of moulting and nesting Graylag goose (grágæs) in Jökulsá á Dal river outwash and geese without goslings by Lagarfljót river. (Project effect: indirect).
  3. Number of nesting Great skuas (skúmur) in Jökulsá á Dal river outwash and utmost part of Úthérað area close to Héraðsflói bay (Project effect: indirect).
Monitoring protocol
  1. Long-tailed duck: Baseline information was gathered 2005-2007. Monitored each year since then.
  2. Graylag goose: Baseline information was gathered in 2005. Study repeated every 5-10 years.
  3. Great skua: Baseline information was gathered 2005-2007. Repeated in 2008, 2009, 2011 and 2013. Monitored each year on a part of the area in the beginning, and every 5-10 years in the whole Úthérað area.

Expectations rather than targets apply for this indicator

  1. Distribution of Long-tailed duck will not change.
  2. Number of molting Graylag goose in Jökulsá á Dal river outwash remains unchanged.
  3. Number of Great skua nests in Jökulsá á Dal river outwash remains unchanged.
Possible countermeasures

None - monitoring only

Updated: December 7, 2015

Changes of indicator

At the annual meeting of the initiative on May 6 2015 the following proposed amendments were passed

Table 1. Changes accepted in annual general meeting 2018
Original text Amended text

What is measured?

  1. Behavior of red-throated diver (lóms) - number of times the birds get food from Lagarfljót river and from the sea (or number of birds per hour at the river and at the sea.
  2. Long-tailed duck (hávella) - distribution in Úthérað area
  3. Number of graylag geese (grágæs) at molting sites in Jökulsá á Dal river outwash
  4. Number of great skua (skúmur) nests in Jökulsá á Dal river outwash

What is measured?

Observation of red-throated diver (lóms) discontinued.

  1. Long-tailed duck (hávella), tufted duck (skúfönd) and mallard (stokkönd) - distribution and count on Lagarfljót river during summer.
  2. Number of molting and nesting graylag geese (grágæs) in Jökulsá á Dal river outwash and geese without goslings by Lagarfljót river.
  3. Number of great skuas (skúmur) in nesting area at Jökulsá á Dal river outwash and outmost part of Úthérað area closest to Héraðsflói bay.

Rationale for amendments

The monitoring protocol has undergone some changes since the project started. All changes are made in consultation with bird experts. Baseline studies in 2004 – 2005 revealed that Red-throated divers do not fetch food in the land or at Lagarfljót river and therefore no reason to monitor them.

Population of Long-tailed duck is not considered the appropriate term. Therefore the monitoring war redefined so as to monitor the distribution of Long-tailed duck at Lagarfljót river during summer. In addition research of other species of the Anatidae family was added.

In the beginning number of molting Graylag geese in Jökulsá á Dal river outwash was monitored. It was changed to number of Graylag geese with goslings and molting geese in Jökulsá á Dal outwash and geese without goslings by Lagarfljót river. This is expected to give better picture.

In the beginning number of Great skua nests were counted but now number of Great skuas is monitored and considered more realistic measure.

All these changes are made in order to capture nature's variability and essential for the initiative to be flexible enough to adjust to natural fluctuations.

The original monitoring protocol was written as follows:

  1. Experts from the Icelandic institute of natural history (IINH) will collect data. Flying directions of the Red-throated divers will be mapped and their behavior monitored at key locations, in order to find out how much food they get from rivers and how much from sea. Baseline studies to take place in the summers of 2004 and 2005.
  2. Experts from the IINH will collect data. Birds will be counted and distribution mapped. Baseline studies to be collected in 2005 and new information collected in 2015.
  3. Experts from the IINH will collect information. Bird count based on both aerial photos and field studies. Baseline studies to be collected in 2005 and new information collected in 2015.
  4. Experts from the IINH will collect information. The birds will be counted every year in the period 2005-2008.

This indicator was originally number 24.3. It was then named Breeding Birds at Úthérað and can be found under that number in documents of the project from 2005 and 2006.

The indicator number has been changed twice.

Table 2. Changes to name and number of indicator
Year Nr. Indicator name
2020 2.5.3 Breeding Birds at Úthérað
2007 2.22 Breeding Birds at Úthérað


It was thought that the establishment of the Kárahnjúkar power plant would possibly affect the food supply of Red-Throated divers in the area affected by the power plant. The behavior of the Red-throated divers was studied in 2004 and 2005 and the results indicated that the bird seeks mainly feed in the ocean, and therefore there was no reason to watch its behavior any further.

Deductions about the impact of the power plant on Long-tailed duck are based on comparison to monitoring done in 2005 during its run-up. East Iceland Natural History Institute has gathered data since 1989 from monitoring of common duck species on Lagarfljót river. The highest number of Long-tailed duck on Lagarfljót river reported in older sources was 440 birds on June 9 1983, this was believed to be related to hard times at the highland lakes in East Iceland (Skarphéðinn Þórisson, 1990). This shows that there are examples of peak numbers of Long-tailed ducks in other years than 2005-2007. The same source states that the Long-tailed duck is the most common migrating duck on Lagarfljót river and that the average number of Long-tailed duck in a flock (May-June) is 107 birds (through 16 counts). All species of ducks on Lagafljót decreased in the years 2009 - 2012 compared to previous years, but have been recovering from the weather in recent years, except for the Mallard. Variability between years is significant. From 2016 to 2019, the number of Tufted duck (Skúfönd), Mallard (Stokkönd)  and Long-tailed ducks (Hávella) seems to be declining. The year 2019 seems particularly sad for these species and the weather in the east of the country can have some effect on that, but the summer was rather cool and humid (Figure 4).

Figure 4. Variations in biggest flocks of Long-tailed duck (Hávella) and Tufted duck (Skúfönd) during spring and Mallard (Stokkönd) during winter on Lagarfljót river.

The great skua were counted in Úthérað from the year 2006 to 2013, with the exception of the years 2010 and 2012. Initially, it was assumed that there would be support from similar research elsewhere, such as from Öxarfjörður and Breiðamerkursandur. No comparable counts are known from Breiðamerkursandur this year, but some observations from Öxarfjörður. A comparison with counts in Öxarfjörður showed that there is also variation in the number between years, as in Úthérað (Figure 5).

Figure 5. Comparison of the development of the number of great skuas at Öxarfjörður and Úthérað (figures from Öxarfjörður from Þorkell Lindberg Þórarinsson et al. 2013).

Revised and updated: May 1, 2020
Source: Landsvirkjun 2017, East Iceland Nature Research Center 2020.

  • Skarphéðinn Þórisson 1990. Fuglalíf við Egilsstaðaflugvöll. Bliki 9: 29-40

  • Þorkell Lindberg Þórarinsson, Aðalsteinn Örn Snæþórsson, Böðvar Þórisson, Guðmundur A. Guðmundsson, Halldór Walter Stefánsson, Kristinn Haukur Skarphéðinsson og Yann Kolbeinsson 2013. Fuglar á Austursandi við Öxarfjörð. Bliki 32: 59–66.

Agreements between Landsvirkjun and East Iceland Nature Reasearch Center in 2017 provided for short reports on developments that would be published to the public in this forum, first when reviewing developments for 2017.

You can view a report from East Iceland Nature Research Center on the results of counting the long-tailed ducks on Lagarfljót and the distribution of great skuas in Úthérað by clicking here (Icelandic only).

Waterfowl and swimming birds on Jökulsá á Dal

Landsvirkjun commissioned the East Iceland Nature Center to study the settlement of waterfowl on Jökulsá á Dal due to changes in the river's ecosystem along with water transport with the introduction of Kárahnjúkar. Observations began in the summer of 2014. In general, they were gulls and Anatidae, with the exception of pink footed and greylag geese. The observations consisted of three days of counting over the summer on and by Jökla river.

Figure 6. The main categories of birds on Jökulsá á Dal from 2014 - 2019

Since the beginning of the inspection of waterfowl and swimming birds at Jökla in 2014, swans have been noticeable. The number of ducks seems rather stable, but greater fluctuations can be detected in the gull species. The amount of red-throated divers in Jökla river Varies (Figure 6). Overall, it can be said that the number of ducks decreased during the period, the number of red-throated diver remained relatively unchanged, the number of gulls, arctic skua and tern fluctuated somewhat and the number of swans increased.

Figure 7. Gulls, arctuc skua, arctic tern, cormorant, red-throated dive and fulmar in Jökla river 2014 – 2019.

Lesser black-backed gull,ílamáfur has been the most common gull at Jökla, but the number in the summer of 2019 was the smallest since 2014. Other waterfowl and swimming birds that are prominent there include Arctic Tern, Red-Throated divers and Arctic skua. Common gull, great cormorant and fulmar are rarer species (Figure 7). In the summer of 2018, the glaucous gull was added to Jökla's species list, one bird.

Figure 8. Anatidae by Jökulsá á Dal 2014-2019

The number of swans is noticable higher than other Anatidae located by Jökla river, with the exeption of the two goose species, greylag goose and red-foooted goose, which are released here. The presence of eight species of ducks indicates that the number is fairly even between years, although the observation period is still too short to draw strong conclusions from. Most of these ducks were only known on the tributaries of Jökla before the water transport (2007) (Figure 8). So far, the Mallard (dabber) is more noticable than the divers in Jökla river, which is of course explained by the supply of food connected to the river. It can be expected that the number of divers will increase in the future. The most common duck on Jökla is precisely harlequin duck, which can also be a measure of food (caddis fly and black fly larva), which are most dear to it during the summer in current water.

Since 2014, arctic skua has been monitored along the river Jökulsá á Dal in connection with an assessment of waterfowl and swimming birds, and the development there has been as Figure 9 shows. Observations in the summer of 2019 gave the second largest number of arctic skua along the Jökla (Skjöldólfsstaðir to Húsey) waterway since 2014.

Figure 9. Development in the number of arctic skua along the channel of Jökla river 2014-2019

The number of arctic skua on a road profile in Hróarstunga in Úthérað between the towns of Húsey and Geirastaðir has been monitored from 2005 to 2019. The development was downwards for the first three years but has fluctuated between six and fifteen birds since then (Figure 10).

Figure 10. Number of arctic skua in the area between Húsey and Geirastaðir 2005-2019

It is possible that more bird species may take advantage of the Jökulsá á Dal channel in the future.

Revised and updated: May 1, 2020
Source: Landsvirkjun og East Iceland Nature Research Center 2020.

Rationale for Indicator Selection

Estimating the impact of the Kárahnjúkar dam on bird life at Úthérað area is difficult since it is affected as much or more by many other factors. Research indicates that hydrologic changes will probably have insignificant impact on vegetation. Therefore, this indicator focuses on bird species expected to be either dependent on Lagarfljót river for food or affected by changes in Jökulsá á Dal river riverbed. For example, it was considered possible that better access to Jökulsá á Dal outwash could lead to fewer graylag geese in molting areas at the outwash plus that easier access for predators could have negative impact on breeding of the great Skua.

From phase I/II report on indicators and baseline from April 2005

Further reading

LV-2017/049 - Vatna- og sundfuglar á Jökulsá á Dal og endur á Lagarfljóti og á vötnum á Fljótsdalsheiði árið 2016.

LV-2017/049 - Vatna- og sundfuglar á Jökulsá á Dal og endur á Lagarfljóti og á vötnum á Fljótsdalsheiði árið 2016.

Náttúrustofa Austurlands annaðist úttekt á völdum fuglategundum á vatnasviði Kárahnjúkavirkjunar fyrir Landsvirkjun sumarið 2016. Endur voru taldar á Lagarfljóti og vötnum á Fljótsdalsheiði auk þess sem vatna- og sundfuglar voru taldir á Jökulsá á Dal (Jöklu) þriðja árið í röð. Í heildina fjölgaði hávellum á Fljóti en fækkaði á heiðarvötnum. Skúföndum fækkaði einnig á Fljótinu en stokkendur stóðu í stað milli ára og líka hávellum á Jöklu. Fuglum fjölgaði hjá nokkrum tegundum á Jöklu m.a. hjá máfum, kjóa, kríu og lóm en einstaklingum hjá nokkrum tegundum andfugla fækkaði og einnig skúmum. Álftum og straumöndum fjölgaði milli ára.

You can view more material related to the indicator by clicking on the link above.