Course: 104.6.0.QNRM Megindlegar rannsóknaraðferðir 6 ETCS

Instructor: Kári Joensen

Semester: Haustönn 2024

Verkefni 2: Einstaklingsverkefni

Leirvogsá
Leirvogsá

Introduction

Last year, I traded my usual dress and heels for waders and a fishing rod—what an adventure that was! My first time fishing at Leirvogsá was not just an outdoor experience; it felt like I was stepping into a new world. Thanks to the patience of my instructor and a dash of beginner’s luck, I was completely hooked—not only on the fishing but also on the tranquility of nature and the thrill of the catch. Now, I’m excited to share my journey and delve into some fascinating data on Iceland’s rivers, starting with my beloved Leirvogsá, a place that made me fall in love with fishing..

My First Catch at Leirvogsá

Me with a Fish Flottur maríulax úr Leirvogsá

Fishing at Leirvogsá was truly unforgettable. The joy of reeling in my first salmon was unparalleled, as you can see in this picture. The thrill of standing by the rushing river, feeling the weight of the fish as it fought, and finally holding it in my hands—it’s an experience I’ll cherish forever.

Flottur lax úr Leirvogsá
Flottur lax úr Leirvogsá

About Leirvogsá River

Leirvogsá is a 12 km long river that flows from the Leirvogsvatn lake into the sea. Known for its salmon fishing, this river has been a favorite spot for local anglers since the Veiðifélag (Fishing Club) was founded in 1940.

The river offers more than just a fishing spot — it’s a sanctuary of natural beauty. Whether you’re a seasoned angler or a first-time visitor, Leirvogsá has something special for everyone.

Here’s me taking a break next to one of the beautiful waterfalls along the river:

Leirvogsá River
Leirvogsá River

Leirvogsá, holds a surprising wealth of fishing experiences. Just a short drive from Reykjavik, it’s easy to forget how close you are to the city once you’re standing in a serene fishing spot like Birgishylur. The river boasts one of the highest catches per rod in Iceland, with over 250 salmon caught in 2020 alone, plus a remarkable number of sea trout. Its 58 designated fishing spots are a mix of riffles, pools, and smooth glides, making each visit a new adventure.

Whether it’s early spring sea trout fishing or exploring diverse fishing spots like Snoppa or Fitjakotshylur, there’s always a new challenge. For anyone eager to land a trophy sea trout, small flies are the secret weapon in the lower sections of the river—though once the season reaches September, it’s fly-only fishing and catch-and-release for all fish. The river may be small, but it sure keeps you on your toes!

Data Analysis

Yearly Catch Data for Leirvogsá

The data below represents yearly salmon catches at Leirvogsá, sourced from the Landsamband Veiðifélaga website.

Year Catch
2024 211
2023 303
2022 455
2021 279
2020 156
2019 113

Next, we can visualize the fluctuation in salmon catches over the years. Below is a line plot showing the number of salmon caught from 2000 to 2024.

Insights

From the line plot above, we can see significant fluctuations in salmon catches over the years. The river’s golden year was 2008, when an impressive 1,173 salmon were caught, followed by a noticeable decline in recent years. However, hope isn’t lost - every year holds new possibilities. Maybe my next week’s fishing trip could help turn things around and lead to a record-breaking catch — stay tuned!

Comparison of Salmon Catches: 2024 (September) vs 2023 (End of Season)

Now, let’s broaden the scope and look at how other rivers in Iceland are doing in terms of salmon catches. The data below compares the catches for September 2024 with the final tallies from 2023 for several key rivers. The season isn’t over yet, so who knows what surprises are in store for the final numbers!

Insights

The bar plot above showcases the catches of various rivers in 2024 and 2023. While some rivers, like Ytri-Rangá, are showing strong numbers, others still have some time to make up ground before the season ends. With my upcoming fishing trip, the season is still wide open, and there’s no telling how the final numbers will look!

Descriptive Statistics for 2023 and 2024

Let’s dive deeper into some key statistics using inline R code: The average number of salmon caught in 2023 across all rivers was 658.07 fish.

As of September 2024, the average catch across rivers is 714.05 fish.

Maximum catch in 2023: The river with the highest number of salmon caught in 2023 was Ytri-Rang, with 3587 salmon.

Maximum catch in 2024 (so far): For 2024, the leading river is Ytri-Rang, with 3084 salmon caught by September.

Interested in More Fishing Data?

For those who want to dive deeper into Iceland’s fishing statistics, there’s another great resource: Laxar.net. On this site, you can find various insights and data related to fishing in Iceland.

Here are some of the highlights:

  1. Fishing News (Fréttir af veiði):
    • Stay up-to-date with the latest fishing reports and news about catches from different rivers.
  2. Interactive Maps:
    • Explore maps showing key fishing spots and river basins.
  3. Comprehensive Statistics (Tölfræði):
    • Watershed Data (Vatnasvið): Explore rivers and their ecosystems.
    • Top Catches (Mesta veiði): Discover rivers with the highest catches.
    • Average Catch per Rod (Meðalveiði á stöng): See the average success rate for anglers.
  4. Detailed Graphs:
    • Catch per Day (Veiði á dag): Visualize daily catch data.
    • Catch by Month (Veiði eftir mánuðum): Analyze how catches change throughout the season.
    • Yearly Comparisons (Dagleg veiði síðustu ár): Compare daily catches over several years.
    • Deviation from Average (Frávik frá meðaltali): See how current catches deviate from historical averages.
    • Best and Worst Years (Besta til versta árið): Rank years from the most successful to the least.
    • Catch by Week (Hlutfallsleg veiði eftir vikum): View the relative distribution of catches by week.
laxar.net - tölfræði
laxar.net - tölfræði

Watch Live Fish Movements

For those truly passionate about monitoring fish behavior in rivers, check out RiverWatcher. They provide real-time videos, compare fish migration patterns, and store high-resolution images of every fish, helping fisheries manage their rivers with precision.

Largest seen this period in Korpa
Largest seen this period in Korpa

For example, check out real-time fish migration in Korpa River: Watch the latest video check out the most recent fish, its length and direction of movement or look at the species report

Counting Report for Korpa
Counting Report for Korpa

Watch te video on YouTube or simply scan the QR code below to watch the video:

Data from Hagstofa Íslands

The following data is sourced directly from Hagstofa Íslands (Statistics Iceland) via their open API, which provides detailed statistics about various sectors, including agriculture, fisheries, and the environment. The dataset used here focuses on salmon catches from Leirvogsá river between the years 1998 and 2022. Specifically, the data provides information on the total weight of salmon caught (Þyngd, kg) and the average weight of individual salmon (Meðalþyngd, kg).

Statistics Iceland plays a crucial role in collecting and publishing official data that helps individuals, companies, and organizations make informed decisions. The salmon catch data offers insights into the trends and fluctuations in catches, which is particularly useful for fisheries management, policy-making, and research purposes.

## pxweb 0.17.0: R tools for the PX-WEB API.
## https://github.com/ropengov/pxweb
Salmon Catch Data from Leirvogsá (1998-2022)
River Year Metric Value
Leirvogsá 1998 Þyngd, kg 1242.0
Leirvogsá 1998 Meðalþyngd, kg 2.3
Leirvogsá 1999 Þyngd, kg 1188.0
Leirvogsá 1999 Meðalþyngd, kg 2.5
Leirvogsá 2000 Þyngd, kg 1123.0
Leirvogsá 2000 Meðalþyngd, kg 2.3
Leirvogsá 2001 Þyngd, kg 975.0
Leirvogsá 2001 Meðalþyngd, kg 2.2
Leirvogsá 2002 Þyngd, kg 1333.0
Leirvogsá 2002 Meðalþyngd, kg 2.5
Leirvogsá 2003 Þyngd, kg 1263.0
Leirvogsá 2003 Meðalþyngd, kg 2.3
Leirvogsá 2004 Þyngd, kg 1912.0
Leirvogsá 2004 Meðalþyngd, kg 2.4
Leirvogsá 2005 Þyngd, kg 1753.0
Leirvogsá 2005 Meðalþyngd, kg 2.4
Leirvogsá 2006 Þyngd, kg 655.0
Leirvogsá 2006 Meðalþyngd, kg 2.2
Leirvogsá 2007 Þyngd, kg 751.0
Leirvogsá 2007 Meðalþyngd, kg 2.0
Leirvogsá 2008 Þyngd, kg 2532.0
Leirvogsá 2008 Meðalþyngd, kg 2.2
Leirvogsá 2009 Þyngd, kg 1646.0
Leirvogsá 2009 Meðalþyngd, kg 2.1
Leirvogsá 2010 Þyngd, kg 1260.0
Leirvogsá 2010 Meðalþyngd, kg 2.3
Leirvogsá 2011 Þyngd, kg 780.0
Leirvogsá 2011 Meðalþyngd, kg 2.2
Leirvogsá 2012 Þyngd, kg 408.0
Leirvogsá 2012 Meðalþyngd, kg 2.0
Leirvogsá 2013 Þyngd, kg 1251.0
Leirvogsá 2013 Meðalþyngd, kg 2.1
Leirvogsá 2014 Þyngd, kg 618.0
Leirvogsá 2014 Meðalþyngd, kg 2.0
Leirvogsá 2015 Þyngd, kg 1489.0
Leirvogsá 2015 Meðalþyngd, kg 2.3
Leirvogsá 2016 Þyngd, kg 748.0
Leirvogsá 2016 Meðalþyngd, kg 2.4
Leirvogsá 2017 Þyngd, kg 115.0
Leirvogsá 2017 Meðalþyngd, kg 2.4
Leirvogsá 2018 Þyngd, kg 559.0
Leirvogsá 2018 Meðalþyngd, kg 2.3
Leirvogsá 2019 Þyngd, kg 184.0
Leirvogsá 2019 Meðalþyngd, kg 2.2
Leirvogsá 2020 Þyngd, kg 496.0
Leirvogsá 2020 Meðalþyngd, kg 2.5
Leirvogsá 2021 Þyngd, kg 454.0
Leirvogsá 2021 Meðalþyngd, kg 2.6
Leirvogsá 2022 Þyngd, kg 610.0
Leirvogsá 2022 Meðalþyngd, kg 2.3

The data from Hagstofa Íslands shows that the total weight of salmon caught in Leirvogsá between 1998 and 2022 fluctuated significantly. The highest recorded weight was 2532 kg, while the lowest was 115 kg. The average weight across all years was 1013.8 kg, indicating some variation over the years.

As for the average weight of individual salmon, the mean weight was 2.28 kg, with a minimum of 2 kg and a maximum of 2.6 kg. This suggests relatively stable sizes for salmon caught in Leirvogsá during this period.

Insights from the Visualizations

The line plot of total weight caught over time shows clear fluctuations, with the highest catch in 2022 (r max(weight_data$Value) kg) and the lowest in 2000 (r min(weight_data$Value) kg). This suggests possible changes in salmon populations or fishing practices over the years.

The bar plot of average salmon weight shows relatively stable figures, indicating consistent sizes of salmon caught over the period. The stacked bar plot helps highlight both the total catch and average weight trends together, giving a deeper understanding of how both the quantity and size of salmon have shifted.

We have gathered information on two key metrics: 1. The total number of salmon caught and 2. The number of salmon released.

Insights

From the plot above, we can observe some interesting trends in the number of salmon caught versus released in Leirvogsá from 1998 to 2022.

Increase in Releases: Over the years, there has been a noticeable increase in the number of salmon being released back into the river. This could reflect increased awareness and commitment to conservation efforts, especially in recent years.

Stable Catches: While the number of caught fish fluctuates, there are years with high catches. However, in comparison, the percentage of salmon released is higher in later years, indicating a growing trend in catch-and-release practices.

This data helps highlight the balance between fishing practices and sustainability. Conservation measures, such as releasing fish back into the river, play a vital role in maintaining healthy salmon populations.

But if there’s one thing I’ve learned from this journey (and these charts), it’s that the fish are always out there… somewhere. You just have to cast your line, trust the data, and wait for that tug.

As I sit here by the waterfall, surrounded by the serenity of Leirvogsá, it becomes clear that fishing isn’t just about the number of salmon caught—or even released for that matter. It’s about patience, the thrill of the chase, and the calm that comes from standing knee-deep in nature.

Leirvogsá River
Leirvogsá River