Indicator 2.22 - Breeding Birds at Úthérad

Estimating the impact of the Kárahnjúkar dam on bird life at Úthérad (the vicinity of the dam) is difficult since many factors influence bird populations in this area. Research indicates that hydrologic changes caused by the dam are not likely to have a significant impact on vegetation in the area.

Therefore, this indicator focuses on bird species that are either dependent on Lagarfljót river for food or species whose habitat could be influenced because of changes in the Jökulsá á Dal river basin. For example, it is possible that increased access to the muddy areas close to Jökulsá á Dal could have a negative impact on moulting sites for the greylag goose and nesting sites for the great skua.

Performance

The original Monitoring Protocol has been changed somewhat, mainly because of outcomes from baseline studies. The following figures reflect these changes.

a. (Not applicable)

b. Distribution of long-tailed duck in Lagarfljót River in the summer.
Graph 1 shows the outcome of research in 2005-2011:

(Colors show 1st, 2nd, 3rd, etc. countings in the year).

In the period from 2005-2011, the number of long-tailed ducks in Lagarfljót River has decreased. One possible explanation could be increased mud in the river because of water from Hálslón Reservoir, which could affect the feeding conditions for long-tailed ducks. Still, that does not have to be the reason, as the reduction can be seen already in 2007 (as compared to 2005 and 2006) and then, Hálslón was filling up for the first time and the bypass of water had not started. Another possible explanation for the reduction could be related to a change in the stock, but not much is known of the condition of the stock in Iceland or whether the distribution has changed in some way.

c. Number of moulting and nesting greylag goose in areas adjacent to Jokulsá á Dal and moulting geese by Lagarfljót river.
The outcome of research will be published in early 2014. .

d. Number of nesting great skuas in areas adjacent to Jokulsá á Dal.

Graph 2 shows the outcome of research in 2000-2011:

The great skua count has not changed beyond natural short time fluctuations in the stock. The graph shows the development in 2000-2011. Please note that no counting was done in 2010.

Source: Landsvirkjun 2005-2012.
Last updated 4 April 2012.

Metrics, Targets & Monitoring Protocol

1. Feeding behaviour of red-throated divers - # of occasions when birds seek feed at Lagarfljót river and the # of occasions they seek feed to the ocean (for instance, number of birds per hour by the river and out on the sea). (Project effect: indirect).
2. Distribution of long-tailed duck in Lagarfljót River in the summer. (Project effect: indirect). 
3. Number of moulting and nesting greylag goose in areas adjacent to Jokulsá á Dal and moulting geese by Lagarfljót river. (Project effect: indirect).
4. Number of nesting great skuas in areas adjacent to Jokulsá á Dal (Project effect: indirect).

1. As for the behavior of red-throated divers, the original plan was to measure the # of occasions when birds seek feed at Lagarfljót river and the # of occasions they seek feed to the ocean. This counting has been stopped, as it became clear during the baseline study that the red-throated diver seeks feed mainly to the ocean.
2. As for the long-tailed duck, original plans discussed the "stock" which is not right, and thus the measurement has been redefined to watch the distribution of the long-tailed duck in Lagarfljót River in the summer.
3. The original metric was number of "moulting" greylag goose in areas in Úthérad and by Lagarfljót River all the way to Fljótsdalur. Now, the number of moulting and nesting greylag geese in  Jokulsá á Dal and moulting geese by Lagarfljót river are counted.
4. The original metric was the number of "great skua nests" in nesting grounds in the areas by Jökulsá á Dal. The present counting involves the number of "great skuas."
   

1. Target not applicable.

2. Distribution of long-tailed duck will not change.

3. Number of moulting greylag goose in areas adjacent to Jökulsá á Dal will remain stable . 

4. Number of nesting great skuas in areas adjacent to Jökulsá á Dalwill remain stable.

Monitoring Protocol

1. Red-throated diver: Monitoring has been stopped.
   

2. Long-tailed duck: Baseline information was gathered 2005-2007. Monitored each year since then and for the first years.

3. Greylag goose: Baseline information was gathered in 2005. Research repeated every 5-10 years.

4. The great skua: Baseline information was gathered 2005-2007. Repeated in 2008 and 2009. Research every year in a part of the area, and every 5-10 years in the whole Hérad area.

To show changes in Monitoring Protocol - following is the original plan:

1. Experts from the IINH will collect information. Flying directions of the red-throated divers will be mapped and documented in some key locations, in order to find out if they go to the ocean for food or to the rivers. Baseline studies to take place in the summers of 2004 and 2005.
   

2. Experts from the IINH will collect information. Birds will be counted and and distribution mapped out. Baseline studies to be collected in 2005 and new information collected in 2015.
   

3. Experts from the IINH will collect information. Experts will count the birds using 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.

Rationale for Indicator Selection

Estimating the impact of the Kárahnjúkar dam on bird life at Úthérad (the vicinity of the dam) is difficult since many factors influence bird populations in this area. Research indicates that hydrologic changes caused by the dam are not likely to have a significant impact on vegetation in the area.

Therefore, this indicator focuses on bird species that are either dependent on Lagarfljót river for food or species whose habitat could be influenced because of changes in the Jökulsá á Dal river basin. For example, it is possible that increased access to the muddy areas close to Jökulsá á Dal could have a negative impact on moulting sites for the greylag goose and nesting sites for the great Skua.

Baseline Studies

The behavior of the red-throated divers was researched 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 and 2009. No comparable counting is available from Öxarfjordur and Breidamerkursandur at that time, and therefore there was no base for comparison. The number of skuas has not changed much, and specialists think that changes between years up to about 30% do not give reason to speculations about changes in the stock.

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).