2.22 Breeding Birds at Úthérað

Indicator 2.22 - Breeding Birds at Úthérað

Visir-2.22-toppmyndBelow is information about research on breeding birds at Úthérað area.

Úthérað is the utmost part of Hérað, outer than Lagarfoss waterfall (see map)



Progress

The original Monitoring Protocol has been changed somewhat, mainly because of outcomes from baseline studies (see notes on changes under "Monitoring Protocol"). The following figures reflect these changes.




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


Long-tailed duck on Lagarfljót river

Figure 1. Long-tailed ducks (Hávellur) on Lagarfljót river 2005 - 2016

Labels: (Colors show 1st, 2nd, 3rd, etc. count (talning) of each year), X-axes:  Year (Ár), Y-axes: number of Long tailed ducks (Fjöldi)

As can be seen in Figure 1, the number of Long-tailed ducks on Lagarfljót river decreased significantly in the period from 2008 - 2012. One possible explanation could be increased turbidity in the river concomitant with water from Hálslón Reservoir, which could affect the feeding conditions for diving ducks. Still, that does not have to be the reason, as the reduction was already apparent in 2007 (as compared to 2006) and then, Hálslón was filling up for the first time and bypass of water had not started. Another possible explanation for fewer Long-tailed ducks on Lagarfljót could be related to population change, but little is known about Long-tailed duck population in Iceland or whether the dispersion has changed in some way.  

Similar number of Long-tailed ducks was observed in 2013 and 2014 as in 2005 - 2007, which indicates external explanations.  In the summer of 2015 the number of Long-tailed ducks on Lagarfljót decreased again.  The weather was cold almost all summer in East Iceland and that could partly explain the decrease between years. In 2016, the number of Long-tailed ducks increased in Lagarfljót river compared to the previous year, an was similar to the years 2009 and 2010. A figure under the tab "baseline studies" shows results of counting three species of ducks, which also indicates a variation in number of ducks that is not necessarily connected to condition of the river.

Source:  Landsvirkjun 2017
Updated:  September 2017


b. Graylag goose

The Graylag goose population was studied in 2005 and again in 2013.  The results plus data, gathered by East Iceland Natural History Institude, 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.     

Source:  Landsvirkjun 2017
Updated: September 2017



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


Number of Great skua in the channel of Jökulsá á Dal river

Figure 2.  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)

Labels:  X-Axes:  Year, Y-axes:  Number of Great skua

Number of Great skua has not changed beyond natural short-term fluctuations in the population.  The development in number in 2005 - 2016 can be seen in figure 2.  Note that no counting was done in 2010 and 2012.

Great skuas have been counted, since 2014, near the channel of Jökulsá á Dal river in connection with a studie 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.

Source: Landsvirkjun 2017
Updated:  September 2017

Monitoring Protocol


Figure 1. Map of Úthérað area, Úthérað is the utmost part of Hérað, outer than Lagarfoss waterfall, marked by black arrow.Figure 1. Map of Úthérað area, Úthérað is the utmost part of Hérað, outer than Lagarfoss waterfall, marked by black arrow.

Based on data from National LandSurvey of Iceland (see terms)


Metrics: 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.


Targets

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.

Countermeasures

None - monitoring only


Metrics - changes from original plans


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

What is measured

Original text: 
Amended text:
  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
 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.


In forth phase of the initiative the numbers of the indicators were changed.  This indicator war originally number 24.3 and is referenced as such in reports issued in 2004 and 2005 about the project.




Baseline Studies

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 behaviour any further.

Great skuas were counted in 2006, 2007, 2008, 2009, 2011 and 2013. Similar research elsewhere like in Öxarfjörður fjord and at Breiðamerkursandur sand were expected to support findings. No comparable counting is available from Breiðamerkursandur sand from that time but few from Öxarfjörður fjord. Comparison to counts in Öxarfjörður and conclusions from the research at Úthérað area show that changes between years up to about 30% do not alone indicate changes in the population.

Figure 1: Number of great skuas (skúma): comparison between Öxarfjörður fjord and Úthérað area (Þorkell Lindberg Þórarinsson et al. 2013)                      Figure 1: Number of Great skuas (skúma): comparison between Öxarfjörður fjord and Úthérað area (Þorkell Lindberg Þórarinsson et al. 2013)

Labels:  X-axis: Year (Ár); Y-axes: Count of Great skua on Austursandur sand by Öxarfjörður fjord (blue) and in Úthérað area (orange).

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. This data shows among other things that all species show considerable variations between years. 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 (Source: 9th issue Bliki, August 1990 „Fuglalíf við flugvelli“). 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).  Count of all duck species decreased in 2009 – 2012 compared to former years, but increases again except the Mallard, but the variation is big (figure 2). The year 2016, the largest groups of Long-tailed ducks and Tufted ducks increased from the year before, but the number of Mallard was the same.


Long-tailed duck, Tufted duck and Mallard in Lagarfljót river2. Variations in biggest flocks of Long-tailed duck (Hávella) and Tufted duck (Skúfönd) during spring and Mallard (Stokkönd) during winter on Lagarfljót river.

Labels:  Long-tailed duck (Hávella):  Blue;  Tufted duck (Skúfönd): Orange;  Mallard (Stokkönd): grey;  X-axis: year (ár);  Y-axis:  number of birds (fjöldi)

Updated: September 2017
Source: Landsvirkjun, 2017

A report made by the East Iceland Institute for Natural Studies on the outcome of long-tailed duck research in Lagarfljót and the nesting distribution of the great skua in Úthérad is available here (in Icelandic only).


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.


Further reading

Reports published by Landsvirkjun and East Iceland Nature Research Centre (only in Icelandic)

Vatna- og sundfuglar á Jökulsá á Dal og endur á Lagarfljóti og vötnum á Fljótsdalsheiði árið 2015.
Report no:  LV-2016-074

Click here to download report.



Áhrif Kárahnjúkavirkjunar á grágæsir.
 Report no:  LV-2014-096

Click here to download report.




Vöktun skúms á Úthéraði 2005 - 2013
Report no:  LV-2014-037:  

Click here to download report.




Andatalningar á Lagarfljóti og á Fljótsdalsheiði árið 2013.
Report no:  LV-2014-034

Click here to download report.




2.22 Fjöldi hávellu á Lagarfljótti - forsíðaHávellur á Lagarfljóti og vötnum á Fljótsdalsheiði árið 2012.
Report no:  LV-2013-040:  

Click here to download report.




skúmur skýrsla 2011 forsíðaVöktun skúms á Úthéraði - Úttekt á varpi við Jökulsá á Dal 2011.
  Report no: NA-120119

Click here to download report.




hávelluskýrsla 2011 forsíðaHávellutalningar á Lagarfljóti og á vötnum í Fljótsdalsheiði 2011.
Report no:  LV-2012-036

Click here to download report.




2.22-skyrsla-LV-2011-038-forsidumyndHávellutalningar á Lagarfljóti.
Report no:  LV-2011/038

Click here to download report.

 

 

 

Hávellutalningar á Lagarfljóti og varpdreifing skúms á Úthéraði 2009.
Report no:  LV-2010/045

Click here to download report.