Bird Predation and Its Impact on Fish Stocks: A Critical Look at the Ribble Catchment

As we close another license period at the Ribble Fisheries Consultative Association (RFCA), the subject of bird predation and its impact on fish stocks, particularly the migration of juvenile salmon (smolts), is at the forefront of our discussions. Our area-based license (ABL) covers the Ribble, Hodder, and Calder catchments, including some local still waters. Part of our central management role involves evaluating intelligence and reports from various sub-licensees regarding the numbers and impact of cormorants and goosanders on our fish stocks. 

The Scope of Our Bird Mitigation Program

Authorised by Natural England, our bird mitigation program employs a variety of scaring tactics. As a last resort, we are issued a very small number of lethal intervention notices. This is not a cull but a carefully regulated intervention aimed at robust management based on evidence and tactics developed over years of observation and research. 

To give you a better understanding, I recommend watching this video by a Scottish ghillie, which explains the principles behind our mitigation efforts. Although it focuses on Scotland, the same commitment to managing bird predation applies to our work in the Ribble catchment. 

Do Fish-Eating Birds Damage Fisheries, Particularly Juvenile Salmon?

The short answer is yes. Over the past 30-35 years, the number of cormorants and goosanders has increased significantly across the country, including in the Ribble catchment. Older anglers often remark how these birds were not seen decades ago. 

As someone involved in managing our ABL, I’ve observed firsthand the impact of bird predation on fish stocks, and I believe this profoundly impacts juvenile salmon, especially in the upper reaches where coarse fish numbers are limited. In these areas, salmonids will be the primary prey for these birds, which correlates with the decline in salmon numbers as observed in surveys by the Ribble River Trust. Likewise, as we have witnessed this year, as the smolts have moved downstream, we have had a build-up of birds. In one instance, up to fifty goosanders were seen on one section of the Ribble. It is important to note that this is just one of several issues compounding declining stock numbers. 

The Wider Context and Supporting Evidence

This issue is not isolated to the Ribble. Research across Europe has highlighted similar impacts. Esteemed salmon angler and ghillie Ian Gordon detailed an experiment in Germany’s Isar River, where bird predation management on certain sections led to a dramatic increase in fish populations, such as grayling, compared to unmanaged sections. This experiment clearly shows the profound impact of fish-eating birds on river ecosystems. 

Despite this evidence, a strong lobby argues against the significant impact of bird predation on fish stocks, delaying effective intervention and management. As salmon numbers continue to decline, the need for balanced ecosystem management becomes more urgent. Some parties may consider this predation to be a natural occurrence, but with multiple factors at play across the riverine system and beyond, the added impact of predation by IUCN Green Listed species such as cormorants and goosanders on juvenile salmon—an IUCN Red Listed species—tips the balance.

The stark warning was made in the Ribble Rivers Trust 2020 Fish Survey Report:

“Fisheries Monitoring of the Ribble Catchment 2020: A stark comparison of long-term sites shows that this year’s Atlantic salmon fry are at their lowest recorded densities on the Ribble and Hodder, with less than 100 fry per 100m² recorded over the 44 long-term sites on each sub-catchment (figure ii). Degradation of Atlantic salmon populations at this rate may lead to unrecoverable numbers by the end of the next decade, with local extinction on the Ribble and its sub-catchments.”

Goosanders Feeding Scared Using A Starter Pistol

Goosanders Feeding Scared Using A Starter Pistol

Goosander taken from The Ribble (Not Smolts)

Goosander taken from The Ribble (Not Smolts)

Recently taken on the Ribble – 26 Goosanders, approximately 50 Goosanders were found in this section. Observed feeding on migrating Smolts now let’s look at the previous images and do the maths!!!

Cormorants Roosting Ribble Catchment

Cormorants Roosting Ribble Catchment… on the evening, this was taken over 100 counted!!! Again, do the maths.

The Contents of a Cormorant

The Contents of a Cormorant: 32 Parr; 3 Sticklebacks; 1 Lamprey (NB – Not Ribble Catchment)

The Need for Action

The debate often revolves around whether continuous monitoring and data collection are sufficient or whether more decisive actions are needed. The RFCA believes that we have gathered ample data over the past decades to justify interventions. Without action, the decline in salmon and other fish species will likely continue, further disrupting the ecological balance and affecting other species that rely on these fish as a food source.

The Broader Ecological Impact

Declining salmon populations do not only affect our local ecosystems but have wider implications. For example, in the Pacific Northwest of the United States, declining Chinook salmon runs have led to significant ecological disruptions. More than 15 Northwest Tribal Nations have demanded federal action to restore salmon in the Snake River and Columbia River Basin, highlighting the critical role salmon play in maintaining healthy ecosystems, including the sustenance of orca populations.

Conclusion

The RFCA is committed to maintaining a balanced ecosystem in the Ribble catchment. While monitoring and data collection are essential, they must lead to effective management strategies. Our bird mitigation program, including regulated lethal interventions, is part of this strategy. It is crucial to understand that without these measures, the negative impact of fish-eating birds on our fish stocks, particularly juvenile salmon, will persist.
For those seeking more information on this topic, I encourage you to watch this informative video:
Let us work together to ensure that our fish stocks, especially our treasured salmon, continue to thrive in the Ribble catchment for generations to come.